WO2017119362A1 - Circularly-polarized-light input/output device - Google Patents

Abstract

[Problem] To provide a circularly-polarized-light input/output device that makes it possible to configure a compact, multi-input/multi-output light switch. [Solution] A circularly-polarized-light input/output device according to the present invention includes: a first polarization diffraction grating that diffracts, when circularly polarized light slanted at angles of +θ and -θ with respect to a thickness direction is incident thereon, the circularly polarized light in the thickness direction before outputting the circularly polarized light; a liquid-crystal polarization rotating element that outputs the circularly polarized light, incident from the first polarization diffraction grating in a direction parallel to the thickness direction, in either a state wherein the rotation direction thereof is reversed or a state wherein the rotation direction thereof is maintained, in the direction parallel to the thickness direction; a second polarization diffraction grating that diffracts the circularly polarized light, incident from the liquid-crystal polarization rotating element in the direction parallel to the thickness direction, in a direction inclined at an angle of either +θ or -θ with respect to the direction parallel to the thickness direction in accordance with the rotation direction before outputting the circularly polarized light; and a circularly-polarized-light irradiation unit that irradiates the first polarization diffraction grating with the circularly polarized light from the direction inclined at the angle of either +θ or -θ with respect to the direction parallel to the thickness direction.

Description

Translated fromJapanese

円偏光入出力装置Circular polarization input / output device

　本発明は、円偏光の回転方向及び回折方向を制御可能とし、光スイッチとして利用可能な円偏光入出力装置に関する。The present invention relates to a circularly polarized light input / output device that can control the rotation direction and diffraction direction of circularly polarized light and can be used as an optical switch.

　従来の技術では、Ｍｉｃｒｏ　Ｅｌｅｃｔｒｏ　Ｍｅｃｈａｎｉｃａｌ　Ｓｙｓｔｅｍｓ（ＭＥＭＳ）ミラーアレイやＬｉｑｕｉｄ　Ｃｒｙｓｔａｌ　ｏｎ　Ｓｉ（ＬＣｏＳ）液晶変調器をスイッチングエンジンとして光スイッチが構成されてきた。
　しかし、これらのスイッチングエンジンでは、低損失に光を偏向できる角度が高々２°程度であることから、光ビームのスイッチングを行う場合、長大な光路長を確保する必要があり、光スイッチを小型化することが困難である。In the prior art, an optical switch has been configured using a Micro Electro Mechanical Systems (MEMS) mirror array or a Liquid Crystal on Si (LCoS) liquid crystal modulator as a switching engine.
However, in these switching engines, the angle at which light can be deflected with low loss is at most about 2 °. Therefore, when switching light beams, it is necessary to ensure a long optical path length and downsize the optical switch. Difficult to do.

　こうしたことから、液晶変調器と、主に＋１次と－１次の回折光が生じる偏光回折格子とで構成される光ビーム偏向器が提案されている（非特許文献１、図１参照）。
　しかしながら、この提案では、図１に示すように１×Ｎ型（Ｎ≧２）の光スイッチに適用できるものの、２入力２出力の光スイッチや複数の入力ポートから複数の出力ポートへ光路の切替えを行う多入力多出力の光スイッチを構成することができない。なお、図１は、従来の光ビーム偏光器における偏光の入出力状況を説明する説明図である。For this reason, a light beam deflector composed of a liquid crystal modulator and a polarization diffraction grating that mainly generates + 1st order and −1st order diffracted light has been proposed (see Non-PatentDocument 1, FIG. 1).
However, although this proposal can be applied to a 1 × N type (N ≧ 2) optical switch as shown in FIG. 1, the optical path is switched from a 2-input 2-output optical switch or a plurality of input ports to a plurality of output ports. It is not possible to construct a multi-input multi-output optical switch. FIG. 1 is an explanatory diagram for explaining the input / output state of polarized light in a conventional light beam polarizer.

　また、第１の偏光回折格子と液晶偏光回転素子と第２の偏光回折格子とで構成される偏光無依存の変調器が提案されている（非特許文献２、図２参照）。
　しかしながら、この提案においても、図２に示すように１入力２出力の光スイッチに適用できるものの、前記２入力２出力の光スイッチや前記多入力多出力の光スイッチを構成することができない配置とされる。なお、図２は、従来の変調器における偏光の入出力状況を説明する説明図である。Further, a polarization-independent modulator composed of a first polarization diffraction grating, a liquid crystal polarization rotation element, and a second polarization diffraction grating has been proposed (see Non-Patent Document 2 and FIG. 2).
However, this proposal can be applied to a 1-input 2-output optical switch as shown in FIG. 2, but the 2-input 2-output optical switch and the multi-input multi-output optical switch cannot be configured. Is done. FIG. 2 is an explanatory diagram for explaining an input / output state of polarized light in a conventional modulator.

　これらの提案で用いられる偏光回折格子は、格子周期を短くすることによって回折角を５°以上とすることが可能であり、この利点を生かした小型で多入力多出力の光スイッチを構成可能な円偏光入出力装置の開発が求められる。The polarization diffraction gratings used in these proposals can have a diffraction angle of 5 ° or more by shortening the grating period, and a compact, multi-input, multi-output optical switch can be constructed taking advantage of this advantage. Development of circularly polarized light input / output device is required.

Jihwan Kim et al., “Wide-angle, nonmechanical beam steering using thin liquid crystal polarization gratings,” Proceedings of SPIE, Vol. 7093, 709302Jihwan Kim et al., “Wide-angle, nonmechanical beam steering using thin liquid crystal polarization gratings,” Proceedings of SPIE, Vol. 7093, 709302Chulwoo Oh et al., “Polarization-independent Modulation Using Standard Liquid Crystal Microdisplays and Polymer Polarization Gratings,” 28th International Display Research Conference, 16.2, Orlando, Florida, United States, Nov 3-6, 2008）Chulwoo Oh et al., “Polarization-independent Modulation Using Standard Liquid Crystal Microdisplays and Polymer Polarization Gratings,” 28th International Display Research Conference, 16.2, Orlando, Florida, United States, Nov 3-6, Nov 3-6,

　本発明は、従来技術における前記諸問題を解決し、小型で多入力多出力の光スイッチを構成可能な円偏光入出力装置を提供することを課題とする。It is an object of the present invention to provide a circularly polarized light input / output device that can solve the above-mentioned problems in the prior art and can constitute a compact, multi-input, multi-output optical switch.

　前記課題を解決するための手段としては、以下の通りである。即ち、
　＜１＞　一の面が入射面とされ、前記一の面と対向する他の面が出射面とされ、θを３°～６０°のいずれかの角度として、厚さ方向に対し＋θ及び－θのいずれかの角度で傾斜するビーム状の円偏光が前記入射面から入射されたときに前記円偏光を前記厚さ方向に回折させて出射面から出射可能とされる平板状の第１の偏光回折格子と、一の面が入射面とされ、前記一の面と対向する他の面が出射面とされるとともに前記第１の偏光回折格子と対向して配され、前記第１の偏光回折格子から前記厚さ方向と平行な方向で前記入射面に入射される前記円偏光に対し、電圧印加に伴うオンオフ制御により、前記円偏光の回転方向を反転させた状態及び前記回転方向を維持させた状態のいずれかの状態とし、この状態の前記円偏光を前記出射面から前記厚さ方向と平行な方向に出射可能とされる平板状の液晶偏光回転素子と、一の面が入射面とされ、前記一の面と対向する他の面が出射面とされるとともに前記液晶偏光回転素子と対向して配され、前記液晶偏光回転素子から前記厚さ方向と平行な方向で前記入射面に入射される前記円偏光を、前記回転方向に応じて、前記厚さ方向と平行な方向から＋θ及び－θのいずれかの角度で傾斜する方向に回折させて前記出射面から出射可能とされる平板状の第２の偏光回折格子と、を有する円偏光回転回折スイッチと、前記第１の偏光回折格子の前記入射面に対し、前記厚さ方向と平行な方向に対し＋θ及び－θのいずれかの角度で傾斜する方向から前記円偏光を照射可能とされる円偏光照射部と、を備えることを特徴とする円偏光入出力装置。
　＜２＞　円偏光回転回折スイッチが、第１の偏光回折格子と液晶偏光回転素子と第２の偏光回折格子とをこの順で積層させて構成される前記＜１＞に記載の円偏光入出力装置。
　＜３＞　第１の偏光回折格子の入射面に対し、前記第１の偏光回折格子の厚さ方向と平行な方向に対し＋θの角度で傾斜する方向から円偏光を照射可能とされる円偏光照射部を第１の円偏光照射部としたとき、更に、前記第１の偏光回折格子の入射面に対し、前記第１の偏光回折格子の厚さ方向と平行な方向に対し－θの角度で傾斜する方向から前記円偏光を照射可能とされる第２の円偏光照射部を有する前記＜１＞から＜２＞のいずれかに記載の円偏光入出力装置。
　＜４＞　更に、第２の偏光回折格子から第１の偏光回折格子の厚さ方向と平行な方向に対して＋θの角度で傾斜する方向に出射される円偏光の出射方向に配され、前記円偏光を受光可能とされる第１の円偏光受光部と、前記厚さ方向と平行な方向に対して－θの角度で傾斜する方向に出射される前記円偏光の出射方向に配され、前記円偏光を受光可能とされる第２の円偏光受光部と、を備える前記＜３＞に記載の円偏光入出力装置。
　＜５＞　１行１列目の円偏光回転回折スイッチの第２の偏光回折格子から第１の偏光回折格子の厚さ方向と平行な方向に対して＋θの角度で傾斜する方向に出射される円偏光の出射方向を行の方向とし、前記１行１列目の円偏光回転回折スイッチの前記第２の偏光回折格子から前記厚さ方向と平行な方向に対して－θの角度で傾斜する方向に出射される前記円偏光の出射方向を列の方向として、Ｍ及びＮを２以上の整数として、Ｍ×Ｎ個の円偏光回転回折スイッチが、それぞれの前記第１の偏光回折格子の入射面及び前記第２の偏光回折格子の出射面を平行な状態としてＭ行Ｎ列のマトリクス格子上に配され、１列目におけるＭ個の前記円偏光回転回折スイッチの前記各第１の偏光回折格子の入射面に対し、前記厚さ方向と平行な方向に対して＋θ及び－θのいずれかの角度で傾斜する方向から前記円偏光を照射可能とされるＭ個の円偏光照射部が配され、Ｍ行目におけるＮ個の前記円偏光回転回折スイッチの前記各第２の偏光回折格子から前記厚さ方向と平行な方向に対して＋θ及び－θのいずれかの角度で傾斜する方向に出射される前記円偏光の出射方向に前記円偏光を受光可能とされるＮ個の円偏光受光部が配される前記＜１＞から＜２＞のいずれかに記載の円偏光入出力装置。
　＜６＞　１行１列目の円偏光回転回折スイッチの第２の偏光回折格子から第１の偏光回折格子の厚さ方向と平行な方向に対して＋θの角度で傾斜する方向に出射される円偏光の出射方向を行の方向とし、前記１行１列目の円偏光回転回折スイッチの前記第２の偏光回折格子から前記厚さ方向と平行な方向に対して－θの角度で傾斜する方向に出射される前記円偏光の出射方向を列の方向として、Ｌを２以上の整数として２Ｌ個の円偏光回転回折スイッチが、それぞれの前記第１の偏光回折格子の入射面及び前記第２の偏光回折格子の出射面を平行な状態としてＬ行Ｌ列の菱形格子上に配され、１列目におけるＬ個の前記円偏光回転回折スイッチの前記各第１の偏光回折格子の入射面に対し、前記厚さ方向と平行な方向に対して＋θ及び－θのいずれかの角度で傾斜する方向から前記円偏光を照射可能とされるＬ個の円偏光照射部が配され、Ｌ行目におけるＬ個の前記円偏光回転回折スイッチの前記各第２の偏光回折格子から前記厚さ方向と平行な方向に対して＋θ及び－θのいずれかの角度で傾斜する方向に出射される前記円偏光の出射方向に前記円偏光を受光可能とされるＬ個の円偏光受光部が配される前記＜５＞に記載の円偏光入出力装置。
　＜７＞　第１の偏光回折格子の入射面及び第２の偏光回折格子の出射面の面内方向に隣接する複数の円偏光回転回折スイッチが、それぞれの前記第１の偏光回折格子及び前記第２の偏光回折格子を、一体形成された１つの部材として共有するように構成される前記＜５＞から＜６＞のいずれかに記載の円偏光入出力装置。
　＜８＞　第２の偏光回折格子から第１の偏光回折格子の厚さ方向と平行な方向に対して＋θ及び－θのいずれかの角度で傾斜する方向に出射される円偏光の出射方向に配され、前記円偏光を受光可能とされる円偏光受光部を有し、前記円偏光受光部の配置位置から前記円偏光受光部における前記円偏光の受光方向と反対方向に円偏光照射部から照射される円偏光と同一の円偏光を照射したとき、前記円偏光照射部から照射される前記円偏光とで共焦点が形成される位置に、円偏光回転回折スイッチが配される前記＜１＞から＜２＞のいずれかに記載の円偏光入出力装置。
　＜９＞　一の面が入射面とされ、前記一の面と対向する他の面が出射面とされ、角度θを３°～６０°のいずれかの角度とし、角度αを０°を超え４５°以下のいずれかの角度とし、かつ、α＋θを９０°未満として、厚さ方向に対し＋（θ＋α）及び－（θ－α）のいずれかの角度で傾斜するビーム状の円偏光が前記入射面から入射されたときに前記円偏光を前記厚さ方向に対し、前記角度αで傾斜する傾斜方向に回折させて出射面から出射可能とされる平板状の第１の偏光回折格子と、一の面が入射面とされ、前記一の面と対向する他の面が出射面とされるとともに前記第１の偏光回折格子と対向して配され、前記第１の偏光回折格子から前記傾斜方向で前記入射面に入射される前記円偏光に対し、電圧印加に伴うオンオフ制御により、前記円偏光の回転方向を反転させた状態及び前記回転方向を維持させた状態のいずれかの状態とし、この状態の前記円偏光を前記出射面から前記傾斜方向に出射可能とされる平板状の液晶偏光回転素子と、一の面が入射面とされ、前記一の面と対向する他の面が出射面とされるとともに前記液晶偏光回転素子と対向して配され、前記液晶偏光回転素子から前記傾斜方向で前記入射面に入射される前記円偏光を、前記回転方向に応じて、前記厚さ方向と平行な方向に対し＋（θ＋α）及び－（θ－α）のいずれかの角度で傾斜する方向に回折させて前記出射面から出射可能とされる平板状の第２の偏光回折格子と、を有する円偏光回転回折スイッチと、前記第１の偏光回折格子の前記入射面に対し、前記厚さ方向と平行な方向に対し＋（θ＋α）及び－（θ－α）のいずれかの角度で傾斜する方向から前記円偏光を照射可能とされる円偏光照射部と、を備えることを特徴とする円偏光入出力装置。Means for solving the problems are as follows. That is,
<1> One surface is an entrance surface, the other surface opposite to the one surface is an exit surface, and θ is any angle from 3 ° to 60 °, and + θ and − A flat plate-shaped first beam that is diffracted in the thickness direction and can be emitted from the emission surface when beam-like circularly polarized light that is inclined at any angle of θ is incident from the incident surface. The polarization grating and one surface is the entrance surface, the other surface facing the one surface is the exit surface, and the first polarization diffraction grating is disposed facing the first polarization grating. With respect to the circularly polarized light incident on the incident surface in a direction parallel to the thickness direction from the diffraction grating, the rotational direction of the circularly polarized light is reversed and the rotational direction is maintained by on / off control accompanying voltage application. The circularly polarized light in this state is moved forward from the exit surface. A flat plate-shaped liquid crystal polarization rotation element capable of emitting light in a direction parallel to the thickness direction, one surface is an incident surface, and the other surface opposite to the one surface is an output surface, and the liquid crystal The circularly polarized light that is arranged opposite to the polarization rotation element and is incident on the incident surface in a direction parallel to the thickness direction from the liquid crystal polarization rotation element is parallel to the thickness direction according to the rotation direction. A circular polarization rotation diffraction switch having a flat plate-like second polarization diffraction grating that is diffracted from any direction into a direction inclined at any angle of + θ and −θ and can be emitted from the emission surface; A circularly polarized light irradiation unit capable of irradiating the circularly polarized light from a direction inclined at any angle of + θ and −θ with respect to a direction parallel to the thickness direction with respect to the incident surface of the first polarization diffraction grating And a circularly polarized light input / output device.
<2> The circularly polarized light input / output according to <1>, wherein the circularly polarized light rotation diffraction switch is configured by laminating a first polarization diffraction grating, a liquid crystal polarization rotation element, and a second polarization diffraction grating in this order. apparatus.
<3> Circularly polarized light that can be irradiated with circularly polarized light from a direction inclined at an angle of + θ with respect to a direction parallel to the thickness direction of the first polarized light diffraction grating with respect to the incident surface of the first polarized light diffraction grating When the irradiation unit is the first circularly polarized light irradiation unit, an angle of −θ with respect to the direction parallel to the thickness direction of the first polarization diffraction grating with respect to the incident surface of the first polarization diffraction grating is further provided. The circularly polarized light input / output device according to any one of <1> to <2>, further including a second circularly polarized light irradiating unit configured to be able to irradiate the circularly polarized light from a direction inclined at a point.
<4> Further, the second polarization diffraction grating is arranged in the emission direction of circularly polarized light emitted in a direction inclined at an angle of + θ with respect to a direction parallel to the thickness direction of the first polarization diffraction grating, A first circularly polarized light receiving part capable of receiving circularly polarized light, and an emission direction of the circularly polarized light emitted in a direction inclined at an angle of −θ with respect to a direction parallel to the thickness direction, The circularly polarized light input / output device according to <3>, further comprising: a second circularly polarized light receiving unit capable of receiving the circularly polarized light.
<5> The light is emitted from the second polarization diffraction grating of the circular polarization rotation diffraction switch in the first row and first column in a direction inclined at an angle of + θ with respect to a direction parallel to the thickness direction of the first polarization diffraction grating. The direction of emission of circularly polarized light is the row direction, and the second polarization diffraction grating of the circularly polarized light rotational diffraction switch in the first row and first column is inclined at an angle of −θ with respect to a direction parallel to the thickness direction. M × N circular polarization rotation diffraction switches are incident on the respective first polarization diffraction gratings, where the emission direction of the circularly polarized light emitted in the direction is a column direction, M and N are integers of 2 or more. The first polarization diffraction of the M circular polarization rotation diffraction switches in the first column is arranged on the matrix grating of M rows and N columns with the plane and the exit surface of the second polarization diffraction grating in parallel. + With respect to the direction parallel to the thickness direction with respect to the incident surface of the grating M circularly polarized light irradiators that can irradiate the circularly polarized light from a direction inclined at any angle of θ and −θ are arranged, and each of the N circularly polarized light rotational diffraction switches in the Mth row is arranged. The circularly polarized light can be received in the emitting direction of the circularly polarized light emitted from the second polarization diffraction grating in a direction inclined at either + θ or −θ with respect to a direction parallel to the thickness direction. The circularly polarized light input / output device according to any one of <1> to <2>, wherein N circularly polarized light receiving units are arranged.
<6> The light is emitted from the second polarization diffraction grating of the circular polarization rotation diffraction switch in the first row and first column in a direction inclined at an angle of + θ with respect to a direction parallel to the thickness direction of the first polarization diffraction grating. The direction of emission of circularly polarized light is the row direction, and the second polarization diffraction grating of the circularly polarized light rotational diffraction switch in the first row and first column is inclined at an angle of −θ with respect to a direction parallel to the thickness direction. 2L circular polarization rotation diffraction switches, where the emission direction of the circularly polarized light emitted in the direction is a column direction and L is an integer of 2 or more, the incident surface of the first polarization diffraction grating and the second Are arranged on L rows and L columns of rhombic gratings with the exit surfaces of the polarization diffraction gratings of the first and second polarization diffraction gratings in the first column being incident on the incident surfaces of the first polarization diffraction gratings. On the other hand, any of + θ and -θ with respect to the direction parallel to the thickness direction. L circularly polarized light irradiating portions that can irradiate the circularly polarized light from a direction inclined at the angle are arranged, and the second polarization diffraction gratings of the L circularly polarized light rotational diffraction switches in the Lth row L circularly polarized lights capable of receiving the circularly polarized light in the emission direction of the circularly polarized light emitted in a direction inclined at any angle of + θ and −θ with respect to a direction parallel to the thickness direction The circularly polarized light input / output device according to <5>, wherein the light receiving unit is arranged.
<7> A plurality of circular polarization rotation diffraction switches adjacent in the in-plane direction of the entrance surface of the first polarization diffraction grating and the exit surface of the second polarization diffraction grating include the first polarization diffraction grating and the first polarization diffraction grating, respectively. The circularly polarized light input / output device according to any one of <5> to <6>, configured to share the two polarization diffraction gratings as one integrally formed member.
<8> In the emission direction of circularly polarized light emitted from the second polarization diffraction grating in a direction inclined at either + θ or −θ with respect to a direction parallel to the thickness direction of the first polarization diffraction grating. A circularly polarized light receiving unit arranged to be capable of receiving the circularly polarized light, and from the circularly polarized light receiving unit in a direction opposite to the circularly polarized light receiving direction from the arrangement position of the circularly polarized light receiving unit. When the same circularly polarized light as the irradiated circularly polarized light is irradiated, the circularly polarized light rotation diffraction switch is disposed at a position where a confocal point is formed with the circularly polarized light irradiated from the circularly polarized light irradiation unit. The circularly polarized light input / output device according to any one of <2> to <2>.
<9> One surface is the entrance surface, the other surface facing the one surface is the exit surface, the angle θ is any angle between 3 ° and 60 °, and the angle α exceeds 0 ° The beam-shaped circularly polarized light is inclined at any angle of + (θ + α) and − (θ−α) with respect to the thickness direction with any angle of 45 ° or less and α + θ less than 90 °. A first polarizing diffraction grating in the form of a plate that can be emitted from the exit surface by diffracting the circularly polarized light in the tilt direction inclined at the angle α with respect to the thickness direction when entering from the entrance surface; One surface is an entrance surface, the other surface facing the one surface is an exit surface, and is disposed facing the first polarization diffraction grating, and is inclined from the first polarization diffraction grating. For the circularly polarized light incident on the incident surface in the direction, the circularly polarized light is controlled by on / off control accompanying voltage application. A plate-like liquid crystal polarization rotator that is in a state in which the rotation direction is reversed or in a state in which the rotation direction is maintained, and the circularly polarized light in this state can be emitted from the emission surface in the tilt direction. One surface is the entrance surface, the other surface facing the one surface is the exit surface, and the liquid crystal polarization rotator is disposed opposite the liquid crystal polarization rotator in the tilt direction. The circularly polarized light incident on the incident surface is tilted at an angle of either + (θ + α) or − (θ−α) with respect to a direction parallel to the thickness direction according to the rotation direction. A circular polarization rotating diffraction switch having a flat plate-like second polarization diffraction grating that can be diffracted and emitted from the exit surface, and the thickness direction with respect to the entrance surface of the first polarization diffraction grating + (Θ + α) and-(θ-α) Circularly polarized light output device, characterized in that it comprises, a circularly polarized light irradiating unit that is capable of irradiating the circularly polarized light from a direction inclined by any angle.

　本発明によれば、従来技術における前記諸問題を解決することができ、小型で多入力多出力の光スイッチを構成可能な円偏光入出力装置を提供することができる。According to the present invention, it is possible to solve the above-mentioned problems in the prior art, and to provide a circularly polarized light input / output device that can constitute a small-sized, multi-input multi-output optical switch.

従来の光ビーム偏光器における偏光の入出力状況を説明する説明図である。It is explanatory drawing explaining the input-output condition of the polarization in the conventional light beam polarizer.従来の変調器における偏光の入出力状況を説明する説明図である。It is explanatory drawing explaining the input-output condition of the polarization in the conventional modulator.第１の偏光回折格子の機能を説明する説明図である。It is explanatory drawing explaining the function of a 1st polarizing diffraction grating.第２の偏光回折格子の機能を説明する説明図である。It is explanatory drawing explaining the function of a 2nd polarizing diffraction grating.第１の偏光回折格子及び第２の偏光回折格子の構成を説明する説明図である。It is explanatory drawing explaining the structure of a 1st polarizing diffraction grating and a 2nd polarizing diffraction grating.液晶偏光回転素子の機能を説明する説明図である。It is explanatory drawing explaining the function of a liquid-crystal polarization | polarized-light rotation element.第１の実施形態に係る円偏光入出力装置の構成を説明する説明図である。It is explanatory drawing explaining the structure of the circularly polarized light input / output device which concerns on 1st Embodiment.第１の実施形態に係る円偏光入出力装置の動作を説明する説明図（１）である。It is explanatory drawing (1) explaining operation | movement of the circularly polarized light input / output device which concerns on 1st Embodiment.第１の実施形態に係る円偏光入出力装置の動作を説明する説明図（２）である。It is explanatory drawing (2) explaining operation | movement of the circularly polarized light input / output device which concerns on 1st Embodiment.第１の実施形態に係る円偏光入出力装置の動作を説明する説明図（３）である。It is explanatory drawing (3) explaining operation | movement of the circularly polarized light input / output device which concerns on 1st Embodiment.第１の実施形態に係る円偏光入出力装置の動作を説明する説明図（４）である。It is explanatory drawing (4) explaining operation | movement of the circularly polarized light input / output device which concerns on 1st Embodiment.第１の実施形態に係る円偏光入出力装置の変形例の動作を説明する説明図（１）である。It is explanatory drawing (1) explaining operation | movement of the modification of the circularly polarized light input / output device which concerns on 1st Embodiment.第１の実施形態に係る円偏光入出力装置の変形例の動作を説明する説明図（２）である。It is explanatory drawing (2) explaining operation | movement of the modification of the circularly polarized light input / output device which concerns on 1st Embodiment.第１の実施形態に係る円偏光入出力装置の変形例の動作を説明する説明図（３）である。It is explanatory drawing (3) explaining operation | movement of the modification of the circularly polarized light input / output device which concerns on 1st Embodiment.第１の実施形態に係る円偏光入出力装置の変形例の動作を説明する説明図（４）である。It is explanatory drawing (4) explaining operation | movement of the modification of the circularly polarized light input / output device which concerns on 1st Embodiment.円偏光回転回折スイッチの構成例を説明する説明図である。It is explanatory drawing explaining the structural example of a circularly polarized light rotation diffraction switch.Ｍ行Ｎ列の光マトリクススイッチを構成する第２の実施形態に係る円偏光入出力装置の構成を説明する説明図である。It is explanatory drawing explaining the structure of the circularly polarized light input / output device which concerns on 2nd Embodiment which comprises the optical matrix switch of a M row N column.Ｌ行Ｌ列の光マトリクススイッチを構成する第３の実施形態に係る円偏光入出力装置の構成を説明する説明図である。It is explanatory drawing explaining the structure of the circularly polarized light input / output apparatus which concerns on 3rd Embodiment which comprises the optical matrix switch of L row L column.第２，３の実施形態の変形例に係る円偏光入出力装置の構成を説明する説明図である。It is explanatory drawing explaining the structure of the circularly polarized light input / output device which concerns on the modification of 2nd, 3rd embodiment.共焦点に円偏光回転回折スイッチを配する構成を示す説明図である。It is explanatory drawing which shows the structure which arrange | positions a circularly polarized light rotation diffraction switch in a confocal.角度θ＋α、θ－αで傾斜させた方向で入出力させる状態を示す説明図（１）である。It is explanatory drawing (1) which shows the state input / output in the direction inclined by angle (theta) + alpha and (theta)-(alpha).角度θ＋α、θ－αで傾斜させた方向で入出力させる状態を示す説明図（２）である。It is explanatory drawing (2) which shows the state input / output in the direction inclined by angle (theta) + alpha and (theta)-(alpha).

（円偏光回転回折スイッチ）
　本発明の円偏光入出力装置に用いられる円偏光回転回折スイッチについて、図３（ａ）～（ｄ）を参照しつつ説明をする。前記円偏光回転回折スイッチは、第１の偏光回折格子と、液晶偏光回転素子と、第２の偏光回折格子とを有する。
　なお、図３（ａ）は、前記第１の偏光回折格子の機能を説明する説明図であり、図３（ｂ）は、前記第２の偏光回折格子の機能を説明する説明図であり、図３（ｃ）は、前記第１の偏光回折格子及び前記第２の偏光回折格子の構成を説明する説明図であり、図３（ｄ）は、前記液晶偏光回転素子の機能を説明する説明図である。(Circularly polarized rotation diffraction switch)
A circularly polarized light rotational diffraction switch used in the circularly polarized light input / output device of the present invention will be described with reference to FIGS. 3 (a) to 3 (d). The circular polarization rotation diffraction switch includes a first polarization diffraction grating, a liquid crystal polarization rotation element, and a second polarization diffraction grating.
3A is an explanatory diagram illustrating the function of the first polarization diffraction grating, and FIG. 3B is an explanatory diagram illustrating the function of the second polarization diffraction grating. FIG. 3C is an explanatory view for explaining the configuration of the first polarization diffraction grating and the second polarization diffraction grating, and FIG. 3D is an explanation for explaining the function of the liquid crystal polarization rotation element. FIG.

　第１の偏光回折格子１０１ａは、平板状の偏光回折格子で構成される（図３（ａ）参照）。また、一の面が入射面とされ、前記一の面と対向する他の面が出射面とされ、θを°３°～６０°、好適には５°～６０°のいずれかの角度として、厚さ方向に対し＋θ及び－θのいずれかの角度で傾斜するビーム状の円偏光が前記入射面から入射されたときに前記円偏光を前記厚さ方向に回折させて出射面から出射可能とされる。The firstpolarization diffraction grating 101a is a flat polarization diffraction grating (see FIG. 3A). Further, one surface is an incident surface, and the other surface opposite to the one surface is an output surface, and θ is set to any angle of 3 ° to 60 °, preferably 5 ° to 60 °. When circular circularly polarized light that is inclined at either + θ or −θ with respect to the thickness direction is incident from the incident surface, the circularly polarized light can be diffracted in the thickness direction and emitted from the output surface. It is said.

　第１の偏光回折格子１０１ａでは、前記入射面に対して垂直に右回り円偏光を入射させると、第１の偏光回折格子１０１ａの厚さ方向（図３（ａ）中のｘ方向）に対して、＋θの角度で傾斜する＋１次の左回り円偏光を前記出射面から出射可能とされる（図３（ａ）の上側参照）。
　また、前記入射面に対して垂直に左回り円偏光を入射させると、第１の偏光回折格子１０１ａの厚さ方向（図３（ａ）中のｘ方向）に対して、－θの角度で傾斜する－１次の右回り円偏光を前記出射面から出射可能とされる（図３（ａ）の下側参照）。
　即ち、第１の偏光回折格子１０１ａでは、入射される円偏光の回転状態に応じて、±１次の方向に回折され、回転方向が入射前の回転方向と反対となる円偏光のみを出射する。
　この状況は、入射及び出射の関係を反対としても同様である。
　なお、図３（ａ）中、第１の偏光回折格子１０１ａに付した矢印は、第１の偏光回折格子１０１ａの周期方向ベクトルの向きを示している。In the firstpolarization diffraction grating 101a, when clockwise circular polarized light is incident perpendicularly to the incident surface, the thickness direction of the firstpolarization diffraction grating 101a (the x direction in FIG. 3A). Thus, + 1st-order counterclockwise circularly polarized light inclined at an angle of + θ can be emitted from the emission surface (see the upper side of FIG. 3A).
Further, when counterclockwise circularly polarized light is incident perpendicularly to the incident surface, it is at an angle of −θ with respect to the thickness direction of the firstpolarization diffraction grating 101a (x direction in FIG. 3A). The inclined first-order clockwise circularly polarized light can be emitted from the emission surface (see the lower side of FIG. 3A).
That is, the firstpolarization diffraction grating 101a emits only circularly polarized light that is diffracted in the ± 1st order direction according to the rotational state of the incident circularly polarized light and whose rotational direction is opposite to the rotational direction before incidence. .
This situation is the same even if the relationship between incidence and emission is reversed.
In FIG. 3A, the arrow attached to the firstpolarization diffraction grating 101a indicates the direction of the periodic direction vector of the firstpolarization diffraction grating 101a.

　第２の偏光回折格子１０１ｂは、平板状の偏光回折格子で構成される（図３（ｂ）参照）。また、一の面が入射面とされ、前記一の面と対向する他の面が出射面とされるとともに液晶偏光回転素子１０３と対向して配され、液晶偏光回転素子１０３から第１の偏光回折格子１０１ａの厚さ方向と平行な方向で前記入射面に入射される前記円偏光を、前記回転方向に応じて、前記厚さ方向と平行な方向から＋θ及び－θのいずれかの角度で傾斜する方向に回折させて前記出射面から出射可能とされる。The secondpolarization diffraction grating 101b is a flat polarization diffraction grating (see FIG. 3B). In addition, one surface is an incident surface, the other surface facing the one surface is an exit surface, and the liquidcrystal polarization rotator 103 is arranged to face the first polarization. The circularly polarized light incident on the incident surface in a direction parallel to the thickness direction of thediffraction grating 101a is at an angle of either + θ or −θ from the direction parallel to the thickness direction, depending on the rotation direction. The light can be diffracted in an inclined direction and can be emitted from the emission surface.

　第２の偏光回折格子１０１ｂでは、前記入射面に対して、第２の偏光回折格子１０１ｂの厚さ方向（図３（ｂ）中のｘ方向）に対し－θの角度で傾斜する左回り円偏光を入射させると、前記円偏光を右回り円偏光として前記厚さ方向に回折させて出射面から出射可能とされる（図３（ｂ）の上側参照）。
　また、前記入射面に対して、第２の偏光回折格子１０１ｂの厚さ方向（図３（ｂ）中のｘ方向）に対し＋θの角度で傾斜する右回り円偏光を入射させると、前記円偏光を左回り円偏光として前記厚さ方向に回折させて出射面から出射可能とされる（図３（ｂ）の下側参照）。
　即ち、第２の偏光回折格子１０１ｂでは、入射される円偏光の回転状態に応じて、±１次の方向に回折され、回転方向が入射前の回転方向と反対となる円偏光のみを出射する。
　この状況は、入射及び出射の関係を反対としても同様である。
　つまり、第２の偏光回折格子１０１ｂと、第１の偏光回折格子１０１ａとは、周期方向ベクトルの向きが異なるのみで同様の構成及び機能を有する。
　なお、図３（ｂ）中、第２の偏光回折格子１０１ｂに付した矢印は、第２の偏光回折格子１０１ｂの周期方向ベクトルの向きを示している。In the secondpolarization diffraction grating 101b, a counterclockwise circle tilted at an angle of −θ with respect to the incident surface with respect to the thickness direction of the secondpolarization diffraction grating 101b (the x direction in FIG. 3B). When polarized light is incident, the circularly polarized light is diffracted in the thickness direction as clockwise circularly polarized light and can be emitted from the exit surface (see the upper side of FIG. 3B).
Moreover, when the clockwise circularly polarized light inclined at an angle of + θ with respect to the thickness direction of the secondpolarization diffraction grating 101b (the x direction in FIG. 3B) is incident on the incident surface, the circle The polarized light is diffracted in the thickness direction as counterclockwise circularly polarized light and can be emitted from the emission surface (see the lower side in FIG. 3B).
That is, the secondpolarization diffraction grating 101b emits only circularly polarized light that is diffracted in the ± 1st order direction according to the rotational state of the incident circularly polarized light and whose rotational direction is opposite to the rotational direction before incidence. .
This situation is the same even if the relationship between incidence and emission is reversed.
That is, the secondpolarization diffraction grating 101b and the firstpolarization diffraction grating 101a have the same configuration and function except that the direction of the periodic direction vector is different.
In FIG. 3B, the arrow attached to the secondpolarization diffraction grating 101b indicates the direction of the periodic direction vector of the secondpolarization diffraction grating 101b.

　第１の偏光回折格子１０１ａ及び第２の偏光回折格子１０１ｂの構成を図３（ｃ）に示す。
　図３（ｃ）に示すように、第１の偏光回折格子１０１ａ及び第２の偏光回折格子１０１ｂでは、長鎖状の分子１０２ａ及び１０２ｂが、第１の偏光回折格子１０１ａ及び第２の偏光回折格子１０１ｂの厚さ方向（図３（ｃ）中のｘ方向）に対し面内で直交する一の方向（図３（ｃ）中のｙ方向）に周期Λで周期的に回転して配向されて配されるとともに、これら長鎖状の分子１０２ａ及び１０２ｂの周期的な構造が、面内で前記一の方向と直交する他の方向（図３（ｃ）中のｚ方向）に一定間隔で並設されて構成される。
　また、第１の偏光回折格子１０１ａ及び第２の偏光回折格子１０１ｂでは、回折角θが、通常の回折格子と同じく、光の波長をλとして次式（１）を満たすように構成される。The configuration of the firstpolarization diffraction grating 101a and the secondpolarization diffraction grating 101b is shown in FIG.
As shown in FIG. 3C, in the firstpolarization diffraction grating 101a and the secondpolarization diffraction grating 101b, the long-chain molecules 102a and 102b are converted into the firstpolarization diffraction grating 101a and the second polarization diffraction diffraction. Oriented by periodically rotating with a period Λ in one direction (y direction in FIG. 3C) perpendicular to the thickness direction of the grating 101b (x direction in FIG. 3C) in the plane. And the periodic structure of thelong chain molecules 102a and 102b is arranged at regular intervals in another direction (z direction in FIG. 3C) perpendicular to the one direction in the plane. It is arranged side by side.
In addition, the firstpolarization diffraction grating 101a and the secondpolarization diffraction grating 101b are configured such that the diffraction angle θ satisfies the following formula (1), where the wavelength of light is λ, similarly to a normal diffraction grating.

　第１の偏光回折格子１０１ａ及び第２の偏光回折格子１０１ｂとしては、このような特徴を有するものであれば特に制限はなく、目的に応じて適宜選択することができ、例えば、特表２００８－５３２０８５号公報等に記載される高回折角の偏光回折格子を用いることができる。The firstpolarization diffraction grating 101a and the secondpolarization diffraction grating 101b are not particularly limited as long as they have such characteristics, and can be appropriately selected according to the purpose. For example, Special Table 2008- A polarizing diffraction grating having a high diffraction angle described in Japanese Patent No. 532085 can be used.

　図３（ｄ）に示すように、液晶偏光回転素子１０３は、平板状の液晶偏光回転素子で構成される。また、一の面が入射面とされ、前記一の面と対向する他の面が出射面とされるとともに第１の偏光回折格子１０１ａ（及び第２の偏光回折格子１０１ｂ）と対向して配され、第１の偏光回折格子１０１ａから第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図３（ｄ）中のｘ方向）で前記入射面に入射される前記円偏光を前記出射面から前記厚さ方向と平行な方向に出射可能とされる。As shown in FIG. 3D, the liquidcrystal polarization rotator 103 is composed of a flat liquid crystal polarization rotator. In addition, one surface is an incident surface, the other surface facing the one surface is an exit surface, and the firstpolarization diffraction grating 101a (and the secondpolarization diffraction grating 101b) is disposed. The circularly polarized light incident on the incident surface in the direction parallel to the thickness direction of the firstpolarization diffraction grating 101a (the x direction in FIG. 3D) is emitted from the firstpolarization diffraction grating 101a. The light can be emitted from the surface in a direction parallel to the thickness direction.

　ここで、液晶偏光回転素子１０３では、電圧を加えたオフ状態において、前記入射面に入射される前記円偏光に対し、前記回転方向を維持させて、前記円偏光を前記出射面から前記厚さ方向と平行な方向（図３（ｄ）のｘ方向）に出射可能とされる（図３（ｄ）の左上及び左下参照）。
　また、電圧を加えないオン状態で、前記入射面に入射される前記円偏光に対し、前記回転方向を反転させて、前記円偏光を前記出射面から前記厚さ方向と平行な方向（図３（ｄ）のｘ方向）に出射可能とされる（図３（ｄ）の右上及び右下参照）。Here, the liquidcrystal polarization rotator 103 maintains the rotation direction of the circularly polarized light incident on the incident surface in the off state where a voltage is applied, and the circularly polarized light from the exit surface has the thickness. The light can be emitted in a direction parallel to the direction (x direction in FIG. 3D) (see the upper left and lower left in FIG. 3D).
Further, in the ON state where no voltage is applied, the rotation direction is reversed with respect to the circularly polarized light incident on the incident surface, and the circularly polarized light is parallel to the thickness direction from the output surface (FIG. 3). The light can be emitted in the x direction of (d) (see the upper right and lower right in FIG. 3D).

　液晶偏光回転素子１０３としては、このような特徴を有するものであれば特に制限はなく、目的に応じて適宜選択することができ、例えば、ｘｙ平面内でｙ方向を向いたホモジニアス配向した液晶分子が電圧印可によって、ｘｙ平面内でｘ方向に傾く構成の液晶位相変調器等の公知の液晶偏光回転素子を用いることができる。なお、液晶の配向によっては、液晶偏光回転素子１０３に代えて、電圧を加えるとオン状態になり、電圧を加えないとオフ状態になるタイプの公知の液晶偏光回転素子も利用することができる。以降では、前記円偏光の回転方向を反転させる状態をオン状態とし、前記円偏光の回転方向を維持させる状態をオフ状態として説明する。The liquid crystalpolarization rotation element 103 is not particularly limited as long as it has such characteristics, and can be appropriately selected according to the purpose. For example, the liquid crystal molecules are homogeneously oriented in the xy plane and oriented in the y direction. A known liquid crystal polarization rotator such as a liquid crystal phase modulator configured to be inclined in the x direction in the xy plane by applying a voltage can be used. Depending on the orientation of the liquid crystal, instead of the liquidcrystal polarization rotator 103, a known liquid crystal polarization rotator of the type that turns on when a voltage is applied and turns off when no voltage is applied can be used. Hereinafter, the state in which the rotation direction of the circularly polarized light is reversed is referred to as an on state, and the state in which the rotation direction of the circularly polarized light is maintained is described as an off state.

　本発明の円偏光入出力装置では、以上に説明した円偏光回転回折スイッチを用いて、小型で多入力多出力の光スイッチを構成可能とする。即ち、前記円偏光回転回折スイッチでは、第１の偏光回折格子１０１ａ及び第２の偏光回折格子１０１ｂの回折角θを３°～６０°として、大きくとることができるため、本発明の円偏光入出力装置では、この特徴を利用して小型で多入力多出力の光スイッチを構成可能とする。In the circularly polarized light input / output device of the present invention, it is possible to construct a small, multi-input, multi-output optical switch by using the circularly polarized rotational diffraction switch described above. That is, in the circular polarization rotation diffraction switch, the firstpolarization diffraction grating 101a and the secondpolarization diffraction grating 101b can have a large diffraction angle θ of 3 ° to 60 °. In the output device, a small and multi-input multi-output optical switch can be configured using this feature.

　前記多入力多出力の光スイッチを構成する円偏光入出力装置としては、（１）１つの円偏光回転回折スイッチに対して２つの円偏光照射部が配される円偏光入出力装置と、（２）１つの円偏光回転回折スイッチに対して１つの円偏光照射部が配される円偏光入出力装置とに大別することができる。
　以下では、前記（１）の一例として第１の実施形態に係る円偏光入出力装置を挙げ、また、前記（２）の例として第２、第３の実施形態に係る各円偏光入出力装置を挙げて、本発明の前記円偏光入出力装置に係る実施形態の例を説明する。As the circularly polarized light input / output device constituting the multi-input multiple-output optical switch, (1) a circularly polarized light input / output device in which two circularly polarized light irradiation units are arranged for one circularly polarized light rotation diffraction switch; 2) It can be roughly classified into a circularly polarized light input / output device in which one circularly polarized light irradiation unit is arranged for one circularly polarized light rotational diffraction switch.
In the following, the circularly polarized light input / output device according to the first embodiment is given as an example of (1), and the circularly polarized light input / output devices according to the second and third embodiments are given as examples of (2). Examples of embodiments according to the circularly polarized light input / output device of the present invention will be described.

（第１の実施形態）
　第１の実施形態に係る円偏光入出力装置１００を図４を参照しつつ説明する。なお、図４は、第１の実施形態に係る円偏光入出力装置１００の構成を説明する説明図である。
　円偏光入出力装置１００は、図４に示すように、第１の偏光回折格子１０１ａ、液晶偏光回転素子１０３及び第２の偏光回折格子１０１ｂを有する円偏光回転回折スイッチ１０６と、第１の円偏光照射部１０４ａと、第２の円偏光照射部１０４ｂと、第１の円偏光受光部１０５ａと、第２の円偏光受光部１０５ｂとを備え、２入力２出力の光スイッチを構成する。(First embodiment)
The circularly polarized light input /output device 100 according to the first embodiment will be described with reference to FIG. FIG. 4 is an explanatory diagram illustrating the configuration of the circularly polarized light input /output device 100 according to the first embodiment.
As shown in FIG. 4, the circularly polarized light input /output device 100 includes a circularly polarized lightrotation diffraction switch 106 having a firstpolarization diffraction grating 101a, a liquid crystalpolarization rotation element 103, and a secondpolarization diffraction grating 101b, and a first circle. The polarizedlight irradiation unit 104a, the second circularly polarizedlight irradiation unit 104b, the first circularly polarizedlight receiving unit 105a, and the second circularly polarizedlight receiving unit 105b are configured to form an optical switch with two inputs and two outputs.

　第１の円偏光照射部１０４ａは、第１の偏光回折格子１０１ａの入射面に対し、第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図４中のｘ方向）に対し＋θの角度で傾斜する方向からビーム状の円偏光を照射可能とされる。
　また、第２の円偏光照射部１０４ｂは、第１の偏光回折格子１０１ａの入射面に対し、第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図４中のｘ方向）に対し－θの角度で傾斜する方向から前記円偏光を照射可能とされる。The first circularly polarizedlight irradiation unit 104a has + θ with respect to the direction parallel to the thickness direction of the firstpolarization diffraction grating 101a (the x direction in FIG. 4) with respect to the incident surface of the firstpolarization diffraction grating 101a. Beam-shaped circularly polarized light can be irradiated from a direction inclined at an angle.
Further, the second circularly polarizedlight irradiation unit 104b is in a direction parallel to the thickness direction of the firstpolarization diffraction grating 101a (the x direction in FIG. 4) with respect to the incident surface of the firstpolarization diffraction grating 101a. The circularly polarized light can be irradiated from a direction inclined at an angle of −θ.

　第１の円偏光照射部１０４ａ及び第２の円偏光照射部１０４ｂとしては、前記円偏光を照射するものであれば特に制限はなく、目的に応じて適宜選択することができ、公知のレーザ光源及び偏光板等で構成される円偏光照射装置を用いることができる。The first circularly polarizedlight irradiation unit 104a and the second circularly polarizedlight irradiation unit 104b are not particularly limited as long as they irradiate the circularly polarized light, and can be appropriately selected according to the purpose. In addition, a circularly polarized light irradiation device including a polarizing plate and the like can be used.

　第１の円偏光受光部１０５ａは、第２の偏光回折格子１０１ｂから第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図４中のｘ方向）に対して＋θの角度で傾斜する方向に出射される円偏光の出射方向に配され、前記円偏光を受光可能とされる。
　また、第２の円偏光受光部１０５ｂは、第２の偏光回折格子１０１ｂから前記厚さ方向と平行な方向（図４中のｘ方向）に対して－θの角度で傾斜する方向に出射される前記円偏光の出射方向に配され、前記円偏光を受光可能とされる。The first circularly polarizedlight receiving unit 105a is inclined at an angle of + θ from the secondpolarization diffraction grating 101b to a direction parallel to the thickness direction of the firstpolarization diffraction grating 101a (the x direction in FIG. 4). The circularly polarized light emitted in the direction is arranged in the emission direction, and the circularly polarized light can be received.
The second circularly polarizedlight receiving unit 105b is emitted from the secondpolarizing diffraction grating 101b in a direction inclined at an angle of −θ with respect to a direction parallel to the thickness direction (x direction in FIG. 4). The circularly polarized light is arranged in the emitting direction of the circularly polarized light and can receive the circularly polarized light.

　第１の円偏光受光部１０５ａ及び第２の円偏光受光部１０５ｂとしては、特に制限はなく、目的に応じて適宜選択することができ、例えば、受光した前記円偏光を目的とする状態の光として外部出力する公知の光出力装置を用いることができる。There is no restriction | limiting in particular as the 1st circular polarization light-receivingpart 105a and the 2nd circular polarization light-receivingpart 105b, According to the objective, it can select suitably, For example, the light of the state which aimed at the received said circularly polarized light A known light output device that outputs externally can be used.

　第１の実施形態に係る円偏光入出力装置１００の動作について、図５（ａ）～（ｄ）を参照しつつ説明をする。なお、図５（ａ）～（ｄ）は、第１の実施形態に係る円偏光入出力装置１００の動作を説明する説明図（１）～（４）である。The operation of the circularly polarized light input /output device 100 according to the first embodiment will be described with reference to FIGS. 5A to 5D are explanatory views (1) to (4) for explaining the operation of the circularly polarized light input /output device 100 according to the first embodiment.

　図５（ａ）に示すように、円偏光入出力装置１００では、第１の円偏光照射部１０４ａから、第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図５（ａ）中のｘ方向）に対し＋θの角度で傾斜する方向で、第１の偏光回折光子１０１ａの入射面に対して左回り円偏光を照射すると、前記左回り円偏光が第１の偏光回折格子１０１ａにより右回り円偏光に変換されるとともに第１の偏光回折格子１０１ａの厚さ方向（図５（ａ）中のｘ方向）に回折され、液晶偏光回転素子１０３に導入される。
　このとき、液晶偏光回転素子１０３が前記オフ状態であると、前記右回り円偏光は、液晶偏光回転素子１０３をそのまま透過して、第２の偏光回折格子１０１ｂに導入される。
　第２の偏光回折格子１０１ｂに導入された前記右回り円偏光は、第２の偏光回折格子１０１ｂにより前記左回り円偏光に変換されるとともに第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図５（ａ）中のｘ方向）に対して－θの角度をもって回折され、第２の円偏光受光部１０５ｂに導入される。As shown in FIG. 5A, in the circularly polarized light input /output device 100, a direction parallel to the thickness direction of the firstpolarization diffraction grating 101a from the first circularly polarizedlight irradiation unit 104a (in FIG. 5A). When the left-handed circularly polarized light is irradiated to the incident surface of the first polarization diffractedphoton 101a in a direction inclined at an angle of + θ with respect to the x-direction of the left-handed circularly polarized light, the left-handed circularly polarized light is The light is converted into clockwise circularly polarized light and diffracted in the thickness direction of the firstpolarization diffraction grating 101 a (x direction in FIG. 5A) and introduced into the liquid crystalpolarization rotation element 103.
At this time, if the liquidcrystal polarization rotator 103 is in the OFF state, the clockwise circularly polarized light passes through the liquidcrystal polarization rotator 103 as it is and is introduced into the secondpolarization diffraction grating 101b.
The clockwise circularly polarized light introduced into the secondpolarizing diffraction grating 101b is converted into the counterclockwise circularly polarized light by the secondpolarizing diffraction grating 101b and parallel to the thickness direction of the firstpolarizing diffraction grating 101a. The light is diffracted at an angle of −θ with respect to the direction (x direction in FIG. 5A) and introduced into the second circularly polarizedlight receiving unit 105b.

　一方、液晶偏光回転素子１０３が前記オン状態であると、図５（ｂ）に示すように、液晶偏光回転素子１０３に導入される前記右回り円偏光は、液晶偏光回転素子１０３により前記左回り円偏光に回転方向が変換され、第２の偏光回折格子１０１ｂに導入される。
　第２の偏光回折格子１０１ｂに導入された前記左回り円偏光は、第２の偏光回折格子１０１ｂにより前記右回り円偏光に変換されるとともに第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図５（ｂ）中のｘ方向）に対して＋θの角度をもって回折され、第１の円偏光受光部１０５ａに導入される。On the other hand, when the liquidcrystal polarization rotator 103 is in the on state, the clockwise circularly polarized light introduced into the liquidcrystal polarization rotator 103 is counterclockwise by the liquidcrystal polarization rotator 103 as shown in FIG. The direction of rotation is converted into circularly polarized light and introduced into the secondpolarization diffraction grating 101b.
The counterclockwise circularly polarized light introduced into the secondpolarization diffraction grating 101b is converted into the clockwise circular polarization by the secondpolarization diffraction grating 101b and parallel to the thickness direction of the firstpolarization diffraction grating 101a. The light is diffracted at an angle of + θ with respect to the direction (x direction in FIG. 5B) and introduced into the first circularly polarizedlight receiving unit 105a.

　次に、図５（ｃ）に示すように、円偏光入出力装置１００では、第２の円偏光照射部１０４ｂから、第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図５（ｃ）中のｘ方向）に対し－θの角度で傾斜する方向で、第１の偏光回折光子１０１ａの入射面に対して右回り円偏光を照射すると、前記右回り円偏光が第１の偏光回折格子１０１ａにより左回り円偏光に変換されるとともに第１の偏光回折格子１０１ａの厚さ方向（図５（ｃ）中のｘ方向）に回折され、液晶偏光回転素子１０３に導入される。
　このとき、液晶偏光回転素子１０３が前記オフ状態であると、前記左回り円偏光は、液晶偏光回転素子１０３をそのまま透過して、第２の偏光回折格子１０１ｂに導入される。
　第２の偏光回折格子１０１ｂに導入された前記左回り円偏光は、第２の偏光回折格子１０１ｂにより前記右回り円偏光に変換されるとともに第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図５（ｃ）中のｘ方向）に対して＋θの角度をもって回折され、第１の円偏光受光部１０５ａに導入される。Next, as shown in FIG. 5C, in the circularly polarized light input /output device 100, a direction parallel to the thickness direction of the firstpolarization diffraction grating 101a from the second circularly polarizedlight irradiation unit 104b (FIG. 5C). When the clockwise circularly polarized light is irradiated to the incident surface of the first polarization diffractedphoton 101a in a direction inclined at an angle of -θ with respect to the x direction in (c), the clockwise circularly polarized light becomes the first polarized light. The light is converted into counterclockwise circularly polarized light by thediffraction grating 101 a and diffracted in the thickness direction of the firstpolarization diffraction grating 101 a (x direction in FIG. 5C) and introduced into the liquid crystalpolarization rotation element 103.
At this time, if the liquidcrystal polarization rotator 103 is in the OFF state, the counterclockwise circularly polarized light is transmitted through the liquidcrystal polarization rotator 103 as it is and is introduced into the secondpolarization diffraction grating 101b.
The counterclockwise circularly polarized light introduced into the secondpolarization diffraction grating 101b is converted into the clockwise circular polarization by the secondpolarization diffraction grating 101b and parallel to the thickness direction of the firstpolarization diffraction grating 101a. The light is diffracted at an angle of + θ with respect to the direction (x direction in FIG. 5C) and introduced into the first circularly polarizedlight receiving unit 105a.

　一方、液晶偏光回転素子１０３が前記オン状態であると、図５（ｄ）に示すように、液晶偏光回転素子１０３に導入される前記左回り円偏光は、液晶偏光回転素子１０３により前記右回り円偏光に回転方向が変換され、第２の偏光回折格子１０１ｂに導入される。
　第２の偏光回折格子１０１ｂに導入された前記右回り円偏光は、第２の偏光回折格子１０１ｂにより前記左回り円偏光に変換されるとともに第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図５（ｄ）中のｘ方向）に対して－θの角度をもって回折され、第２の円偏光受光部１０５ｂに導入される。On the other hand, when the liquidcrystal polarization rotator 103 is in the on state, the counterclockwise circularly polarized light introduced into the liquidcrystal polarization rotator 103 is rotated clockwise by the liquidcrystal polarization rotator 103 as shown in FIG. The direction of rotation is converted into circularly polarized light and introduced into the secondpolarization diffraction grating 101b.
The clockwise circularly polarized light introduced into the secondpolarizing diffraction grating 101b is converted into the counterclockwise circularly polarized light by the secondpolarizing diffraction grating 101b and parallel to the thickness direction of the firstpolarizing diffraction grating 101a. The light is diffracted at an angle of −θ with respect to the direction (x direction in FIG. 5D) and introduced into the second circularly polarizedlight receiving unit 105b.

　以上のように、円偏光入出力装置１００では、第１の円偏光照射部１０４ａから円偏光回転回折スイッチ１０６に入力される円偏光を、液晶偏光回転素子１０３のオンオフ動作に基づき、第１の円偏光受光部１０５ａ及び第２の円偏光受光部１０５ｂの２つの出力先を選択して出力させるとともに、第２の円偏光照射部１０４ｂから円偏光回転回折スイッチ１０６に入力される円偏光を、液晶偏光回転素子１０３のオンオフ動作に基づき、第１の円偏光受光部１０５ａ及び第２の円偏光受光部１０５ｂの２つの出力先を選択して出力させることができ、第１の円偏光照射部１０４ａ及び第２の円偏光照射部１０４ｂの２つの入力を切替えて利用する２入力２出力の光スイッチとして構成することができる。As described above, in the circularly polarized light input /output device 100, the circularly polarized light input from the first circularly polarizedlight irradiation unit 104 a to the circularly polarized lightrotation diffraction switch 106 is changed based on the on / off operation of the liquid crystalpolarization rotation element 103. While selecting and outputting two output destinations of the circularly polarizedlight receiving unit 105a and the second circularly polarizedlight receiving unit 105b, the circularly polarized light input to the circularly polarized lightrotation diffraction switch 106 from the second circularly polarizedlight irradiating unit 104b, Based on the on / off operation of the liquidcrystal polarization rotator 103, two output destinations of the first circularly polarizedlight receiving unit 105a and the second circularly polarizedlight receiving unit 105b can be selected and output. It can be configured as a two-input two-output optical switch that switches between two inputs of the 104a and the second circularly polarizedlight irradiation unit 104b.

　なお、円偏光入出力装置１００では、第１の偏光回折格子１０１ａの周期方向ベクトルの向きと、第２の偏光回折格子１０１ｂの周期方向ベクトルの向きとを反対方向に設定しているが（図４、図５（ａ）～（ｄ）参照）、これらの周期方向ベクトルの向きを同一方向に設定しても、２入力２出力の光スイッチとして構成することができる。
　周期方向ベクトルの向きを同一方向に設定した変形例である円偏光入出力装置１００’の動作について、図５（ｅ）～（ｈ）を参照しつつ説明する。なお、図５（ｅ）～（ｈ）は、第１の実施形態に係る円偏光入出力装置の変形例の動作を説明する説明図（１）～（４）である。In the circular polarization input /output device 100, the direction of the periodic direction vector of the firstpolarization diffraction grating 101a and the direction of the periodic direction vector of the secondpolarization diffraction grating 101b are set in opposite directions (see FIG. 4 and FIGS. 5 (a) to 5 (d)), even if the direction of these periodic direction vectors is set to the same direction, it can be configured as a 2-input 2-output optical switch.
The operation of the circularly polarized light input /output device 100 ′, which is a modification in which the direction of the periodic direction vector is set to the same direction, will be described with reference to FIGS. 5 (e) to 5 (h). 5E to 5H are explanatory views (1) to (4) for explaining the operation of the modification of the circularly polarized light input / output device according to the first embodiment.

　図５（ｅ）に示すように、円偏光入出力装置１００’では、第１の円偏光照射部１０４ａから、第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図５（ｅ）中のｘ方向）に対し＋θの角度で傾斜する方向で、第１の偏光回折光子１０１ａの入射面に対して左回り円偏光を照射すると、前記左回り円偏光が第１の偏光回折格子１０１ａにより右回り円偏光に変換されるとともに第１の偏光回折格子１０１ａの厚さ方向（図５（ｅ）中のｘ方向）に回折され、液晶偏光回転素子１０３に導入される。
　このとき、液晶偏光回転素子１０３が前記オフ状態であると、前記右回り円偏光は、液晶偏光回転素子１０３をそのまま透過して、第２の偏光回折格子１０１ｂに導入される。
　第２の偏光回折格子１０１ｂに導入された前記右回り円偏光は、第２の偏光回折格子１０１ｂにより前記左回り円偏光に変換されるとともに第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図５（ｅ）中のｘ方向）に対して＋θの角度をもって回折され、第１の円偏光受光部１０５ａに導入される。As shown in FIG. 5E, in the circularly polarized light input /output device 100 ′, a direction parallel to the thickness direction of the firstpolarization diffraction grating 101a from the first circularly polarizedlight irradiation unit 104a (FIG. 5E). When the left-handed circularly polarized light is irradiated to the incident surface of the first polarization diffractedphoton 101a in a direction inclined at an angle of + θ with respect to the x direction in the middle, the left-handed circularly polarized light is converted into the firstpolarization diffraction grating 101a. Is converted into clockwise circularly polarized light, diffracted in the thickness direction of the firstpolarization diffraction grating 101 a (x direction in FIG. 5E), and introduced into the liquid crystalpolarization rotation element 103.
At this time, if the liquidcrystal polarization rotator 103 is in the OFF state, the clockwise circularly polarized light passes through the liquidcrystal polarization rotator 103 as it is and is introduced into the secondpolarization diffraction grating 101b.
The clockwise circularly polarized light introduced into the secondpolarizing diffraction grating 101b is converted into the counterclockwise circularly polarized light by the secondpolarizing diffraction grating 101b and parallel to the thickness direction of the firstpolarizing diffraction grating 101a. The light is diffracted at an angle of + θ with respect to the direction (x direction in FIG. 5 (e)) and introduced into the first circularly polarizedlight receiving unit 105a.

　一方、液晶偏光回転素子１０３が前記オン状態であると、図５（ｆ）に示すように、液晶偏光回転素子１０３に導入される前記右回り円偏光は、液晶偏光回転素子１０３により前記左回り円偏光に回転方向が変換され、第２の偏光回折格子１０１ｂに導入される。
　第２の偏光回折格子１０１ｂに導入された前記左回り円偏光は、第２の偏光回折格子１０１ｂにより前記右回り円偏光に変換されるとともに第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図５（ｆ）中のｘ方向）に対して－θの角度をもって回折され、第２の円偏光受光部１０５ｂに導入される。On the other hand, when the liquidcrystal polarization rotator 103 is in the ON state, the clockwise circularly polarized light introduced into the liquidcrystal polarization rotator 103 is counterclockwise by the liquidcrystal polarization rotator 103 as shown in FIG. The direction of rotation is converted into circularly polarized light and introduced into the secondpolarization diffraction grating 101b.
The counterclockwise circularly polarized light introduced into the secondpolarization diffraction grating 101b is converted into the clockwise circular polarization by the secondpolarization diffraction grating 101b and parallel to the thickness direction of the firstpolarization diffraction grating 101a. The light is diffracted at an angle of −θ with respect to the direction (x direction in FIG. 5 (f)) and introduced into the second circularly polarizedlight receiving unit 105 b.

　次に、図５（ｇ）に示すように、円偏光入出力装置１００’では、第２の円偏光照射部１０４ｂから、第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図５（ｇ）中のｘ方向）に対し－θの角度で傾斜する方向で、第１の偏光回折光子１０１ａの入射面に対して右回り円偏光を照射すると、前記右回り円偏光が第１の偏光回折格子１０１ａにより左回り円偏光に変換されるとともに第１の偏光回折格子１０１ａの厚さ方向（図５（ｇ）中のｘ方向）に回折され、液晶偏光回転素子１０３に導入される。
　このとき、液晶偏光回転素子１０３が前記オフ状態であると、前記左回り円偏光は、液晶偏光回転素子１０３をそのまま透過して、第２の偏光回折格子１０１ｂに導入される。
　第２の偏光回折格子１０１ｂに導入された前記左回り円偏光は、第２の偏光回折格子１０１ｂにより前記右回り円偏光に変換されるとともに第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図５（ｇ）中のｘ方向）に対して－θの角度をもって回折され、第２の円偏光受光部１０５ｂに導入される。Next, as shown in FIG. 5G, in the circularly polarized light input /output device 100 ′, a direction parallel to the thickness direction of the firstpolarization diffraction grating 101a (see FIG. 5) from the second circularly polarizedlight irradiation unit 104b. When the clockwise circularly polarized light is applied to the incident surface of the first polarization diffractedphoton 101a in a direction inclined at an angle of −θ with respect to the x direction in (g), the clockwise circularly polarized light is The light is converted into counterclockwise circularly polarized light by thepolarization diffraction grating 101 a and is diffracted in the thickness direction of the firstpolarization diffraction grating 101 a (x direction in FIG. 5G) and introduced into the liquid crystalpolarization rotation element 103.
At this time, if the liquidcrystal polarization rotator 103 is in the OFF state, the counterclockwise circularly polarized light is transmitted through the liquidcrystal polarization rotator 103 as it is and is introduced into the secondpolarization diffraction grating 101b.
The counterclockwise circularly polarized light introduced into the secondpolarization diffraction grating 101b is converted into the clockwise circular polarization by the secondpolarization diffraction grating 101b and parallel to the thickness direction of the firstpolarization diffraction grating 101a. The light is diffracted at an angle of −θ with respect to the direction (x direction in FIG. 5G) and introduced into the second circularly polarizedlight receiving unit 105b.

　一方、液晶偏光回転素子１０３が前記オン状態であると、図５（ｈ）に示すように、液晶偏光回転素子１０３に導入される前記左回り円偏光は、液晶偏光回転素子１０３により前記右回り円偏光に回転方向が変換され、第２の偏光回折格子１０１ｂに導入される。
　第２の偏光回折格子１０１ｂに導入された前記右回り円偏光は、第２の偏光回折格子１０１ｂにより前記左回り円偏光に変換されるとともに第１の偏光回折格子１０１ａの厚さ方向と平行な方向（図５（ｈ）中のｘ方向）に対して＋θの角度をもって回折され、第１の円偏光受光部１０５ａに導入される。On the other hand, when the liquidcrystal polarization rotator 103 is in the ON state, the counterclockwise circularly polarized light introduced into the liquidcrystal polarization rotator 103 is rotated clockwise by the liquidcrystal polarization rotator 103 as shown in FIG. The direction of rotation is converted into circularly polarized light and introduced into the secondpolarization diffraction grating 101b.
The clockwise circularly polarized light introduced into the secondpolarizing diffraction grating 101b is converted into the counterclockwise circularly polarized light by the secondpolarizing diffraction grating 101b and parallel to the thickness direction of the firstpolarizing diffraction grating 101a. The light is diffracted at an angle of + θ with respect to the direction (x direction in FIG. 5 (h)) and introduced into the first circularly polarizedlight receiving unit 105a.

　以上のように、第１の偏光回折格子１０１ａの周期方向ベクトルの向きと、第２の偏光回折格子１０１ｂの周期方向ベクトルの向きとを同一方向に設定した円偏光入出力装置１００’においても、これら周期方向ベクトルの向きが反対方向に設定された円偏光入出力装置１００と同様に、２入力２出力の光スイッチとして構成することができる。As described above, also in the circular polarization input /output device 100 ′ in which the direction of the periodic direction vector of the firstpolarization diffraction grating 101a and the direction of the periodic direction vector of the secondpolarization diffraction grating 101b are set in the same direction, Similar to the circularly polarized light input /output device 100 in which the directions of these periodic direction vectors are set in opposite directions, it can be configured as a two-input two-output optical switch.

　また、第１の実施形態に係る円偏光入出力装置１００（及びその変形例である円偏光入出力装置１００’）では、第１の偏光回折格子１０１ａ－液晶偏光回転素子１０３間、及び、液晶偏光回転素子１０３－第２の偏光回折格子１０１ｂ間に間隔を空けて、これらを対向させた状態で説明をしたが、これらは、図６に示すように、第１の偏光回折格子１０１ａ、液晶偏光回転素子１０３及び第２の偏光回折格子１０１ｂの順で積層されて、一体の円偏光回転回折スイッチ１０６を構成してもよい。このような構成とすることで、より小型の光スイッチを構成することができる。なお、図６は、円偏光回転回折スイッチの構成例を説明する説明図である。In the circularly polarized light input /output device 100 according to the first embodiment (and the circularly polarized light input /output device 100 ′, which is a modification thereof), the liquid crystal between the firstpolarization diffraction grating 101a and the liquidcrystal polarization rotator 103, and the liquid crystal Although the description has been made with thepolarization rotating element 103 and the secondpolarization diffraction grating 101b spaced apart from each other and facing each other, as shown in FIG. 6, these are the firstpolarization diffraction grating 101a, the liquid crystal Thepolarization rotation element 103 and the secondpolarization diffraction grating 101b may be stacked in this order to form an integrated circular polarizationrotation diffraction switch 106. With such a configuration, a smaller optical switch can be configured. FIG. 6 is an explanatory diagram illustrating a configuration example of a circularly polarized light rotation diffraction switch.

　また、第１の実施形態に係る円偏光入出力装置１００（及びその変形例である円偏光入出力装置１００’）では、前記（１）の態様の最も簡素な例として、２入力２出力の光スイッチの構成例で説明を行ったが、２つの前記円偏光回転回折スイッチを１つの前記円偏光回転回折スイッチの２つの出力方向に配して、より多入力で多出力の光スイッチを構成することができる。
　以下に説明する第２、第３の各実施形態においては、こうした多入力多出力の光スイッチの構成例として説明する。Further, in the circularly polarized light input / output device 100 (and the circularly polarized light input /output device 100 ′ which is a modified example thereof) according to the first embodiment, as the simplest example of the aspect of (1), two inputs and two outputs are provided. As described in the configuration example of the optical switch, the two circular polarization rotation diffraction switches are arranged in the two output directions of the one circular polarization rotation diffraction switch to configure a multi-input and multi-output optical switch. can do.
In each of the second and third embodiments described below, description will be given as an example of the configuration of such a multi-input multi-output optical switch.

（第２の実施形態）
　第２の実施形態に係る円偏光入出力装置１１０を図７を参照しつつ説明する。
　円偏光入出力装置１１０では、１行１列目の円偏光回転回折スイッチ１０６－１１の前記第２の偏光回折格子から前記第１の偏光回折格子の厚さ方向と平行な方向に対して＋θの角度で傾斜する方向に出射される前記円偏光の出射方向を行の方向とし、１行１列目の円偏光回転回折スイッチ１０６－１１の前記第２の偏光回折格子から前記厚さ方向と平行な方向に対して－θの角度で傾斜する方向に出射される円偏光の出射方向を列の方向として、３×４＝１２個の円偏光回転回折スイッチ１０６－１１～１０６－３４（１１～３４の数字は、行列の数字に対応する）が、それぞれの前記第１の偏光回折格子の入射面及び前記第２の偏光回折格子の出射面を平行な状態として３行４列のマトリクス格子上に配される。
　また、１列目における３個の円偏光回転回折スイッチ１０６－１１～１０６－３１の前記各第１の偏光回折格子の入射面に対し、前記厚さ方向と平行な方向に対し－θの角度で傾斜する方向から前記円偏光を照射可能とされる３個の円偏光照射部１０４ａ～１０４ｃが配され、３行目における４個の円偏光回転回折スイッチ１０６－３１～１０６－３４の前記各第２の偏光回折格子から前記厚さ方向と平行な方向に対して－θの角度で傾斜する方向に出射される前記円偏光の出射方向に前記円偏光を受光可能とされる４個の円偏光受光部（１０５ａ～１０５ｄ）が配される。(Second Embodiment)
A circularly polarized light input /output device 110 according to a second embodiment will be described with reference to FIG.
In the circularly polarized light input /output device 110, + θ with respect to the direction parallel to the thickness direction of the first polarization diffraction grating from the second polarization diffraction grating of the circular polarization rotation diffraction switch 106-11 in the first row and the first column. The direction of emission of the circularly polarized light emitted in the direction inclined at an angle of is the direction of the row, and the thickness direction from the second polarization diffraction grating of the circularly polarized light rotational diffraction switch 106-11 in the first row and the first column is 3 × 4 = 12 circularly polarized rotational diffraction switches 106-11 to 106-34 (11), where the direction of emission of circularly polarized light emitted in a direction inclined at an angle of −θ with respect to the parallel direction is the column direction. The numbers 34 to 34 correspond to the numbers in the matrix), but the entrance surface of each of the first polarization diffraction gratings and the exit surface of the second polarization diffraction gratings are parallel to each other in a 3 × 4 matrix lattice. Arranged above.
In addition, an angle of −θ with respect to the direction parallel to the thickness direction with respect to the incident surface of each of the first polarization diffraction gratings of the three circularly polarized light diffraction switches 106-11 to 106-31 in the first row The three circularly polarizedlight irradiating units 104a to 104c that can irradiate the circularly polarized light from the direction tilted at 4 are arranged, and each of the four circularly polarized light rotational diffraction switches 106-31 to 106-34 in the third row is arranged. Four circles capable of receiving the circularly polarized light in the emission direction of the circularly polarized light emitted from the second polarization diffraction grating in a direction inclined at an angle of −θ with respect to a direction parallel to the thickness direction. Polarized light receiving units (105a to 105d) are arranged.

　このように構成される円偏光入出力装置１１０では、各円偏光回転回折スイッチ１０６－１１～１０６－３４が、円偏光入出力装置１００における円偏光回転回折スイッチ１０６と同様に動作し、３入力４出力の光スイッチを構成することができる。In the circularly polarized light input /output device 110 configured as described above, each of the circularly polarized light rotational diffraction switches 106-11 to 106-34 operates in the same manner as the circularly polarized lightrotational diffraction switch 106 in the circularly polarized light input /output device 100, and has three inputs. A 4-output optical switch can be configured.

　なお、円偏光入出力装置１１０では、３入力４出力の光スイッチを構成することとしたが、本発明の円偏光入出力装置は、Ｍ及びＮを２以上の整数としたＭ行Ｎ列のマトリクス格子に適用することで、任意のＭ入力Ｎ出力の光スイッチを構成することができる。
　また、円偏光入出力装置１１０は、円偏光回転回折スイッチ１０６－１１～１０６－３４の周期ベクトルの向きを適宜変更することで、円偏光照射部１０４ａ～１０４ｃを、前記厚さ方向と平行な方向に対し＋θの角度で傾斜する方向から前記円偏光を照射することとし、円偏光受光部１０５ａ～１０５ｄを、前記厚さ方向と平行な方向に対して＋θの角度で傾斜する方向から前記円偏光を受光することとして、各要素の配置が変更されてもよい。In the circularly polarized light input /output device 110, an optical switch having 3 inputs and 4 outputs is configured. However, the circularly polarized light input / output device of the present invention has M rows and N columns, where M and N are integers of 2 or more. By applying to a matrix lattice, an optical switch with any M input and N output can be configured.
In addition, the circularly polarized light input /output device 110 changes the direction of the periodic vectors of the circularly polarized light rotational diffraction switches 106-11 to 106-34 as appropriate so that the circularly polarizedlight irradiation units 104a to 104c are parallel to the thickness direction. The circularly polarized light is irradiated from a direction inclined at an angle of + θ with respect to the direction, and the circularly polarizedlight receiving portions 105a to 105d are irradiated from the direction inclined at an angle of + θ with respect to a direction parallel to the thickness direction. The arrangement of each element may be changed by receiving polarized light.

（第３の実施形態）
　次に、第３の実施形態に係る円偏光入出力装置１２０を図８を参照しつつ説明する。
　円偏光入出力装置１２０は、円偏光入出力装置１１０と異なり、行の数と列の数とが同数とされる。
　即ち、円偏光入出力装置１２０では、１行１列目の円偏光回転回折スイッチ１０６－１１の前記第２の偏光回折格子から前記第１の偏光回折格子の厚さ方向と平行な方向に対して＋θの角度で傾斜する方向に出射される前記円偏光の出射方向を行の方向とし、１行１列目の円偏光回転回折スイッチ１０６－１１の前記第２の偏光回折格子から前記厚さ方向と平行な方向に対して－θの角度で傾斜する方向に出射される円偏光の出射方向を列の方向として、３×３＝９個の円偏光回転回折スイッチ１０６－１１～１０６－３３（１１～３３の数字は、行列の数字に対応する）が、それぞれの前記第１の偏光回折格子の入射面及び前記第２の偏光回折格子の出射面を平行な状態として３行３列の菱形格子上に配される。
　また、１列目における３個の円偏光回転回折スイッチ１０６－１１～１０６－３１の前記各第１の偏光回折格子の入射面に対し、前記厚さ方向と平行な方向に対し－θの角度で傾斜する方向から前記円偏光を照射可能とされる３個の円偏光照射部１０４ａ～１０４ｃが配され、３行目における３個の円偏光回転回折スイッチ１０６－３１～１０６－３３の前記各第２の偏光回折格子から前記厚さ方向と平行な方向に対して－θの角度で傾斜する方向に出射される前記円偏光の出射方向に前記円偏光を受光可能とされる３個の円偏光受光部１０５ａ～１０５ｃが配される。(Third embodiment)
Next, a circularly polarized light input /output device 120 according to a third embodiment will be described with reference to FIG.
Unlike the circularly polarized light input /output device 110, the circularly polarized light input /output device 120 has the same number of rows and columns.
That is, in the circularly polarized light input /output device 120, the second polarization diffraction grating of the circular polarization rotation diffraction switch 106-11 in the first row and the first column extends from the second polarization diffraction grating to a direction parallel to the thickness direction of the first polarization diffraction grating. The direction of emission of the circularly polarized light emitted in the direction inclined at an angle of + θ is the direction of the row, and the thickness from the second polarization diffraction grating of the circularly polarized light rotational diffraction switch 106-11 in the first row and the first column 3 × 3 = 9 circularly polarized light rotational diffraction switches 106-11 to 106-33, where the emission direction of the circularly polarized light emitted in the direction inclined at an angle of −θ with respect to the direction parallel to the direction is the column direction. (The numbers 11 to 33 correspond to the numbers in the matrix.) However, the entrance surface of each of the first polarization diffraction grating and the exit surface of the second polarization diffraction grating are parallel to each other in 3 rows and 3 columns. Arranged on a rhombus lattice.
In addition, an angle of −θ with respect to the direction parallel to the thickness direction with respect to the incident surface of each of the first polarization diffraction gratings of the three circularly polarized light diffraction switches 106-11 to 106-31 in the first row The three circularly polarizedlight irradiating units 104a to 104c that can irradiate the circularly polarized light from the direction tilted at the right and left are arranged, and the three circularly polarized light rotational diffraction switches 106-31 to 106-33 in the third row are arranged. Three circles that can receive the circularly polarized light in the emission direction of the circularly polarized light emitted from the second polarization diffraction grating in a direction inclined at an angle of −θ with respect to a direction parallel to the thickness direction. Polarizedlight receiving portions 105a to 105c are arranged.

　このように構成される円偏光入出力装置１２０では、各円偏光回転回折スイッチ１０６－１１～１０６－３３が、円偏光入出力装置１００における円偏光回転回折スイッチ１０６と同様に動作し、３入力３出力の光スイッチを構成することができる。
　また、円偏光入出力装置１２０では、円偏光照射部１０４ａ～１０４ｃと円偏光受光部１０５ａ～１０５ｃとの間で、１対１の光接続を３！通りに設定することが可能であり、円偏光入出力装置１１０よりも用いる前記円偏光回転回折スイッチの数が少なく、より小型で効果的な光接続の設定を行うことができる。In the circularly polarized light input /output device 120 configured as described above, each of the circularly polarized light rotational diffraction switches 106-11 to 106-33 operates in the same manner as the circularly polarized lightrotational diffraction switch 106 in the circularly polarized light input /output device 100, and has three inputs. A three-output optical switch can be configured.
In the circularly polarized light input /output device 120, the one-to-one optical connection between the circularly polarizedlight irradiating units 104a to 104c and the circularly polarizedlight receiving units 105a to 105c is 3! The number of the circularly polarized light rotational diffraction switches used is smaller than that of the circularly polarized light input /output device 110, and a more compact and effective optical connection can be set.

　なお、円偏光入出力装置１２０では、３入力３出力の光スイッチを構成することとしたが、本発明の円偏光入出力装置は、Ｌを２以上の整数としたＬ行Ｌ列の菱形格子に適用することで、任意のＬ入力Ｌ出力の光スイッチを構成することができる。
　また、円偏光入出力装置１２０は、円偏光回転回折スイッチ１０６－１１～１０６－３３の周期ベクトルの向きを適宜変更することで、円偏光照射部１０４ａ～１０４ｃを、前記厚さ方向と平行な方向に対し＋θの角度で傾斜する方向から前記円偏光を照射することとし、円偏光受光部１０５ａ～１０５ｃを、前記厚さ方向と平行な方向に対して＋θの角度で傾斜する方向から前記円偏光を受光することとして、各要素の配置が変更されてもよい。In the circularly polarized light input /output device 120, an optical switch having 3 inputs and 3 outputs is configured. However, the circularly polarized light input / output device of the present invention has an L row and L column rhombus lattice in which L is an integer of 2 or more. By applying to, an optical switch with any L input and L output can be configured.
In addition, the circularly polarized light input /output device 120 changes the direction of the periodic vectors of the circularly polarized light rotational diffraction switches 106-11 to 106-33 as appropriate so that the circularly polarizedlight irradiation units 104a to 104c are parallel to the thickness direction. The circularly polarized light is irradiated from a direction inclined at an angle of + θ with respect to the direction, and the circularly polarizedlight receiving portions 105a to 105c are irradiated from the direction inclined at an angle of + θ with respect to a direction parallel to the thickness direction. The arrangement of each element may be changed by receiving polarized light.

　次に、第２，３の実施形態の変形例に係る円偏光入出力装置１３０について図９を参照しつつ説明する。なお、図９は、第２，３の実施形態の変形例に係る円偏光入出力装置の構成を説明する説明図である。
　円偏光入出力装置１３０では、前記第１の偏光回折格子の入射面及び前記第２の偏光回折格子の出射面の面内方向に隣接する複数の前記円偏光回転回折スイッチが、それぞれの前記第１の偏光回折格子及び前記第２の偏光回折格子を、一体形成された１つの部材として共有するように構成された一体型円偏光回転回折スイッチ１０７－１～１０７－５を有して構成される。
　ここで、一体型円偏光回転回折スイッチ１０７－１，１０７－３，１０７－５のそれぞれは、前記第１の偏光回折格子及び前記第２の偏光回折格子が一体形成されるものの、５つに分割された液晶偏光回転素子に応じて、５つの前記円偏光回転回折スイッチとして機能する。
　また、一体型円偏光回転回折スイッチ１０７－２，１０７－４のそれぞれについても、前記第１の偏光回折格子及び前記第２の偏光回折格子が一体形成されるものの、４つに分割された液晶偏光回転素子に応じて、４つの前記円偏光回転回折スイッチとして機能する。Next, a circularly polarized light input /output device 130 according to a modification of the second and third embodiments will be described with reference to FIG. In addition, FIG. 9 is explanatory drawing explaining the structure of the circularly polarized light input / output apparatus which concerns on the modification of 2nd, 3rd embodiment.
In the circular polarization input /output device 130, a plurality of the circular polarization rotation diffraction switches adjacent to each other in the in-plane direction of the incident surface of the first polarization diffraction grating and the output surface of the second polarization diffraction grating, One polarization diffraction grating and the second polarization diffraction grating are configured to have an integrated circular polarization rotation diffraction switch 107-1 to 107-5 configured to share as one integrally formed member. The
Here, each of the integrated circular polarization rotation diffraction switches 107-1, 107-3, and 107-5 includes five of the first polarization diffraction grating and the second polarization diffraction grating that are integrally formed. Depending on the divided liquid crystal polarization rotation element, it functions as the five circular polarization rotation diffraction switches.
Further, each of the integrated circular polarization rotation diffraction switches 107-2 and 107-4 is formed by dividing the liquid crystal into four parts, although the first polarization diffraction grating and the second polarization diffraction grating are integrally formed. Depending on the polarization rotation element, it functions as the four circular polarization rotation diffraction switches.

　この円偏光入出力装置１３０では、一体型円偏光回転回折スイッチ１０７－１～１０７－５が、それぞれ前記第１の偏光回折格子の入射面及び前記第２の偏光回折格子の出射面の面内方向に隣接する複数の前記円偏光回転回折スイッチを間隔を設けずに一体に集積させて構成されるため、一体型円偏光回転回折スイッチ１０７－１～１０７－５における前記円偏光回転回折スイッチの数を最適化することにより、より小型の光スイッチを構成することも可能となる。In this circularly polarized light input /output device 130, the integrated circularly polarized light rotational diffraction switches 107-1 to 107-5 are respectively in the planes of the entrance surface of the first polarization diffraction grating and the exit surface of the second polarization diffraction grating. Since the plurality of circularly polarized light rotary diffraction switches adjacent to each other in the direction are integrally integrated without any interval, the circularly polarized light rotary diffraction switches 107-1 to 107-5 in the integrated circularly polarized light rotary diffraction switches 107-1 to 107-5 are integrated. By optimizing the number, a smaller optical switch can be configured.

　また、円偏光入出力装置１３０では、一体型円偏光回転回折スイッチ１０７－１，１０７－５の中央に存在する１つの前記円偏光回転回折スイッチ、一体型円偏光回転回折スイッチ１０７－２，１０７－４の中央に存在する２つの前記円偏光回転回折スイッチ、及び一体型円偏光回転回折スイッチ１０７－３の中央に存在する３つの前記円偏光回転回折スイッチにより、円偏光入出力装置１２０と同様に３入力３出力の光スイッチを構成することができる。
　円偏光入出力装置１３０では、円偏光照射部１０４ｂ，１０４ｃが、前記３入力３出力の光スイッチに関与する前記円偏光回転回折スイッチに対して、一体型円偏光回転回折スイッチ１０７－１乃至１０７－２を介して間接的に円偏光を照射し、円偏光受光部１０５ｂ，１０５ｃが前記３入力３出力の光スイッチに関与する前記円偏光回転回折スイッチに対して、一体型円偏光回転回折スイッチ１０７－４乃至１０７－５を介して間接的に円偏光を受光する態様とされるが、このような態様についても前記円偏光照射部及び前記円偏光受光部の一態様として、本発明の円偏光入出力装置の思想に含まれる。Further, in the circularly polarized light input /output device 130, the one circularly polarized light rotational diffraction switch 107-2, 107 that exists in the center of the integral circularly polarized light rotational diffraction switch 107-1, 107-5. As in the circularly polarized light input /output device 120, the two circularly polarized light rotating diffraction switches present at the center of the -4 and the three circularly rotating light rotating diffraction switches present at the center of the integrated circularly polarized light rotating diffraction switch 107-3. Thus, an optical switch with three inputs and three outputs can be configured.
In the circularly polarized light input /output device 130, the circularly polarizedlight irradiating units 104b and 104c are integrated with the circularly polarized light rotational diffraction switches 107-1 to 107 with respect to the circularly polarized light rotational diffraction switches involved in the 3-input 3-output optical switch. In contrast to the circularly polarized light rotating diffraction switch in which circularly polarized light is indirectly irradiated via -2, and the circularly polarizedlight receiving portions 105b and 105c are involved in the 3-input 3-output optical switch, an integrated circularly polarized light rotating diffraction switch Although the circularly polarized light is indirectly received through 107-4 to 107-5, the circularly polarized light receiving part and the circularly polarized light receiving part of this aspect are also used as one aspect of the present invention. It is included in the idea of a polarization input / output device.

　次に、前記円偏光回転回折スイッチ、前記円偏光照射部及び前記円偏光受光部の好適な位置関係について図１０を参照しつつ説明する。なお、共焦点に円偏光回転回折スイッチを配する構成を示す説明図である。Next, a preferred positional relationship among the circularly polarized light rotation diffraction switch, the circularly polarized light irradiation unit, and the circularly polarized light receiving unit will be described with reference to FIG. In addition, it is explanatory drawing which shows the structure which arrange | positions a circularly polarized light rotation diffraction switch in a confocal.

　この例では、前記第２の偏光回折格子から前記第１の偏光回折格子の厚さ方向と平行な方向に対して＋θ及び－θのいずれかの角度で傾斜する方向に出射される円偏光の出射方向に配され、前記円偏光を受光可能とされる円偏光受光部１０５ａ（１０５ｂ，１０５ｃ）を有し、円偏光受光部１０５ａ（１０５ｂ，１０５ｃ）の配置位置から円偏光受光部１０５ａ（１０５ｂ，１０５ｃ）における前記円偏光の受光方向と反対方向に円偏光照射部１０４ａ（１０４ｂ，１０４ｃ）から照射される円偏光と同一の円偏光を照射したとき、円偏光照射部１０４ａ（１０４ｂ，１０４ｃ）から照射される前記円偏光とで共焦点が形成される位置に、前記円偏光回転回折スイッチが配される。In this example, circularly polarized light emitted from the second polarization diffraction grating in a direction inclined at either + θ or −θ with respect to a direction parallel to the thickness direction of the first polarization diffraction grating. It has a circularly polarizedlight receiving part 105a (105b, 105c) arranged in the emission direction and capable of receiving the circularly polarized light, and the circularly polarizedlight receiving part 105a (105b) from the position where the circularly polarizedlight receiving part 105a (105b, 105c) is arranged. , 105c), the circularly polarizedlight irradiation unit 104a (104b, 104c) is irradiated with the same circularly polarized light as the circularly polarized light irradiated from the circularly polarizedlight irradiation unit 104a (104b, 104c) in the opposite direction to the light receiving direction of the circularly polarized light. The circularly polarized light rotation diffraction switch is disposed at a position where a confocal point is formed with the circularly polarized light irradiated from the circularly polarized light.

　円偏光照射部１０４ａ（１０４ｂ，１０４ｃ）から照射される前記円偏光と、円偏光受光部１０５ａ（１０５ｂ，１０５ｃ）の配置位置から照射される前記円偏光とにおける光ビームのスポット半径を√２ω_０とすると、共焦点での前記光ビームのスポット半径は、ω_ｏ程度に狭小化する。
　このとき、レイリー範囲であるｆは、下記式（２）のように表すことができる。The spot radius of the light beam in the circularly polarized light irradiated from the circularly polarizedlight irradiation unit 104a (104b, 104c) and the circularly polarized light irradiated from the arrangement position of the circularly polarizedlight receiving unit 105a (105b, 105c) is √2ω₀ Then, the spot radius of the light beam at the confocal point is narrowed to about ω_o .
At this time, f which is the Rayleigh range can be expressed as the following formula (2).

　ただし、前記式（２）中のλは、動作波長を示す。

However, λ in the equation (2) represents an operating wavelength.

　円偏光照射部１０４ａ（１０４ｂ，１０４ｃ）から照射される、スポット直径２√２ωｏの光ビームの波面は、共焦点位置に近づくにつれて平坦となる。その後、平坦化された前記光ビームの波面は、前記円偏光回転回折スイッチでの回折により、円偏光受光部１０５ａ（１０５ｂ，１０５ｃ）の配置位置に近づくにつれて円弧となり、再びスポット直径２√２ωｏの光ビームとなる。
　したがって、共焦点レンズ系の共焦点位置に前記円偏光回転回折スイッチを配置することで、回折損失が低減されて低損失なスイッチ動作が可能となる。
　図１０に示す例では、５つの前記一体型円偏光回転回折スイッチのうち、中央の一体型円偏光回転回折スイッチが共焦点位置に配されるように、左右２つずつの前記一体型円偏光回転回折スイッチ、円偏光照射部１０４ａ（１０４ｂ，１０４ｃ）及び円偏光受光部１０５ａ（１０５ｂ，１０５ｃ）が配されることが好ましい。つまり、前記円偏光回転回折スイッチが複数配される場合には、これら円偏光回転回折スイッチが複数配される領域の略中心位置が前記共焦点位置とされることが好ましい。The wavefront of the light beam with a spot diameter of 2√2ωo irradiated from the circularly polarizedlight irradiation unit 104a (104b, 104c) becomes flat as it approaches the confocal position. Thereafter, the wavefront of the flattened light beam becomes a circular arc as it approaches the position where the circularly polarizedlight receiving portions 105a (105b, 105c) are arranged due to diffraction by the circularly polarized light diffraction switch, and again has a spot diameter of 2√2ωo. It becomes a light beam.
Therefore, by disposing the circularly polarized light rotation diffraction switch at the confocal position of the confocal lens system, the diffraction loss is reduced and a low loss switch operation is possible.
In the example shown in FIG. 10, two integrated left and right circular polarization switches are arranged so that the central integrated circular polarization rotation diffraction switch is arranged at the confocal position among the five integrated circular polarization rotation diffraction switches. It is preferable that a rotary diffraction switch, a circularly polarizedlight irradiation unit 104a (104b, 104c), and a circularly polarizedlight receiving unit 105a (105b, 105c) are arranged. That is, when a plurality of circularly polarized light rotation diffraction switches are arranged, it is preferable that a substantially center position of a region where the plurality of circularly polarized light rotation diffraction switches are arranged be the confocal position.

　以上に説明した諸実施形態では、偏光回折格子に対して、右回り円偏光及び左回り円偏光を、前記偏光回折格子の厚さ方向に対し、角度θで傾斜させた方向で入出力させる構成を示したが、図１１及び図１２に示すように角度θ＋α，θ－αで傾斜させた方向で入出力させることも可能である。この態様では、円偏光回転回折スイッチを構成する諸部材中で、前記円偏光が前記偏光回折格子の厚さ方向に対し角度αで傾斜する方向で伝搬する。角度αとしては、０°を超え４５°以下であり、好適には、１°～１５°である。また、角度θ＋αとしては、９０°未満である。この態様とすると、反射光などの迷光が入りにくい利点がある。なお、図１１及び図１２は、角度θ＋α、θ－αで傾斜させた方向で入出力させる状態を示す説明図（１）、（２）である。
　なお、その他の事項については、前述の諸実施形態で説明した事項を適用することができる。In the embodiments described above, a configuration in which clockwise circularly polarized light and counterclockwise circularly polarized light are input to and output from the polarization diffraction grating in a direction inclined at an angle θ with respect to the thickness direction of the polarization diffraction grating. However, as shown in FIGS. 11 and 12, it is also possible to input and output in directions inclined by angles θ + α and θ−α. In this aspect, the circularly polarized light propagates in a direction inclined at an angle α with respect to the thickness direction of the polarization diffraction grating in the members constituting the circularly polarized light diffraction switch. The angle α is more than 0 ° and not more than 45 °, and preferably 1 ° to 15 °. Further, the angle θ + α is less than 90 °. This aspect has an advantage that stray light such as reflected light is difficult to enter. 11 and 12 are explanatory views (1) and (2) showing a state in which input / output is performed in directions inclined by angles θ + α and θ−α.
Note that the items described in the above-described embodiments can be applied to other items.

　１００，１００’１１０，１２０，１３０　円偏光入出力装置
　　　１０１ａ　　第１の偏光回折格子
　　　１０１ｂ　　第２の偏光回折格子
　１０２ａ，１０２ｂ　長鎖状の分子
　　　１０３　　　液晶偏光回転素子
　　１０４ａ～ｃ　円偏光照射部
　　１０５ａ～ｄ　円偏光受光部
　１０６，１０６－１１～１０６－３４　円偏光回転回折スイッチ
　　１０７－１～１０７－５　一体型円偏光回転回折スイッチ100, 100 '110, 120, 130 Circularly polarized light input /output device 101a Firstpolarization diffraction grating 101b Secondpolarization diffraction grating 102a, 102bLong chain molecule 103 Liquid crystalpolarization rotation element 104a-c Circularly polarizedlight irradiation unit 105a- d Circularly polarizedlight receiving unit 106, 106-11 to 106-34 Circularly polarized light rotational diffraction switch 107-1 to 107-5 Integrated circularly polarized light rotational diffraction switch

Claims (9)

Translated fromJapanese

　一の面が入射面とされ、前記一の面と対向する他の面が出射面とされ、θを３°～６０°のいずれかの角度として、厚さ方向に対し＋θ及び－θのいずれかの角度で傾斜するビーム状の円偏光が前記入射面から入射されたときに前記円偏光を前記厚さ方向に回折させて出射面から出射可能とされる平板状の第１の偏光回折格子と、
　一の面が入射面とされ、前記一の面と対向する他の面が出射面とされるとともに前記第１の偏光回折格子と対向して配され、前記第１の偏光回折格子から前記厚さ方向と平行な方向で前記入射面に入射される前記円偏光に対し、電圧印加に伴うオンオフ制御により、前記円偏光の回転方向を反転させた状態及び前記回転方向を維持させた状態のいずれかの状態とし、この状態の前記円偏光を前記出射面から前記厚さ方向と平行な方向に出射可能とされる平板状の液晶偏光回転素子と、
　一の面が入射面とされ、前記一の面と対向する他の面が出射面とされるとともに前記液晶偏光回転素子と対向して配され、前記液晶偏光回転素子から前記厚さ方向と平行な方向で前記入射面に入射される前記円偏光を、前記回転方向に応じて、前記厚さ方向と平行な方向から＋θ及び－θのいずれかの角度で傾斜する方向に回折させて前記出射面から出射可能とされる平板状の第２の偏光回折格子と、を有する円偏光回転回折スイッチと、
　前記第１の偏光回折格子の前記入射面に対し、前記厚さ方向と平行な方向に対し＋θ及び－θのいずれかの角度で傾斜する方向から前記円偏光を照射可能とされる円偏光照射部と、
　を備えることを特徴とする円偏光入出力装置。One surface is the entrance surface, the other surface opposite to the one surface is the exit surface, and θ is any angle from 3 ° to 60 °, and any of + θ and −θ with respect to the thickness direction A plate-shaped first polarization diffraction grating that is capable of diffracting the circularly polarized light in the thickness direction and exiting from the exit surface when beam-like circularly polarized light that is inclined at such an angle is incident from the entrance surface. When,
One surface is an entrance surface, the other surface facing the one surface is an exit surface, and is disposed to face the first polarization diffraction grating, and the thickness from the first polarization diffraction grating is With respect to the circularly polarized light incident on the incident surface in a direction parallel to the vertical direction, either the state in which the rotational direction of the circularly polarized light is reversed or the state in which the rotational direction is maintained is controlled by on / off control accompanying voltage application. A plate-like liquid crystal polarization rotation element capable of emitting the circularly polarized light in this state from the emission surface in a direction parallel to the thickness direction,
One surface is an entrance surface, the other surface facing the one surface is an exit surface, and is disposed facing the liquid crystal polarization rotator, and is parallel to the thickness direction from the liquid crystal polarization rotator. The circularly polarized light incident on the incident surface in any direction is diffracted in a direction inclined at either + θ or −θ from a direction parallel to the thickness direction in accordance with the rotation direction. A circular polarization rotation diffraction switch having a flat plate-like second polarization diffraction grating that can be emitted from a surface;
Circularly polarized light irradiation capable of irradiating the circularly polarized light from a direction inclined at any angle of + θ and −θ with respect to a direction parallel to the thickness direction with respect to the incident surface of the first polarization diffraction grating And
A circularly polarized light input / output device comprising:　円偏光回転回折スイッチが、第１の偏光回折格子と液晶偏光回転素子と第２の偏光回折格子とをこの順で積層させて構成される請求項１に記載の円偏光入出力装置。The circularly polarized light input / output device according to claim 1, wherein the circularly polarized light rotation diffraction switch is configured by laminating a first polarization diffraction grating, a liquid crystal polarization rotation element, and a second polarization diffraction grating in this order.　第１の偏光回折格子の入射面に対し、前記第１の偏光回折格子の厚さ方向と平行な方向に対し＋θの角度で傾斜する方向から円偏光を照射可能とされる円偏光照射部を第１の円偏光照射部としたとき、更に、前記第１の偏光回折格子の入射面に対し、前記第１の偏光回折格子の厚さ方向と平行な方向に対し－θの角度で傾斜する方向から前記円偏光を照射可能とされる第２の円偏光照射部を有する請求項１から２のいずれかに記載の円偏光入出力装置。A circularly polarized light irradiation unit capable of irradiating circularly polarized light from a direction inclined at an angle of + θ with respect to a direction parallel to a thickness direction of the first polarized light diffraction grating with respect to an incident surface of the first polarized light diffraction grating; When the first circularly polarized light irradiation unit is used, the first polarized light diffraction grating is further inclined at an angle of −θ with respect to a direction parallel to the thickness direction of the first polarized light diffraction grating with respect to the incident surface of the first polarized light diffraction grating. 3. The circularly polarized light input / output device according to claim 1, further comprising a second circularly polarized light irradiating unit capable of irradiating the circularly polarized light from a direction.　更に、第２の偏光回折格子から第１の偏光回折格子の厚さ方向と平行な方向に対して＋θの角度で傾斜する方向に出射される円偏光の出射方向に配され、前記円偏光を受光可能とされる第１の円偏光受光部と、前記厚さ方向と平行な方向に対して－θの角度で傾斜する方向に出射される前記円偏光の出射方向に配され、前記円偏光を受光可能とされる第２の円偏光受光部と、を備える請求項３に記載の円偏光入出力装置。Furthermore, the circularly polarized light is arranged in the emission direction of circularly polarized light emitted from the second polarization diffraction grating in a direction inclined at an angle of + θ with respect to a direction parallel to the thickness direction of the first polarization diffraction grating. A first circularly polarized light receiving portion capable of receiving light, and arranged in an emission direction of the circularly polarized light emitted in a direction inclined at an angle of −θ with respect to a direction parallel to the thickness direction, and the circularly polarized light The circularly polarized light input / output device according to claim 3, further comprising: a second circularly polarized light receiving unit that can receive the light.　１行１列目の円偏光回転回折スイッチの第２の偏光回折格子から第１の偏光回折格子の厚さ方向と平行な方向に対して＋θの角度で傾斜する方向に出射される円偏光の出射方向を行の方向とし、前記１行１列目の円偏光回転回折スイッチの前記第２の偏光回折格子から前記厚さ方向と平行な方向に対して－θの角度で傾斜する方向に出射される前記円偏光の出射方向を列の方向として、Ｍ及びＮを２以上の整数として、Ｍ×Ｎ個の円偏光回転回折スイッチが、それぞれの前記第１の偏光回折格子の入射面及び前記第２の偏光回折格子の出射面を平行な状態としてＭ行Ｎ列のマトリクス格子上に配され、
　１列目におけるＭ個の前記円偏光回転回折スイッチの前記各第１の偏光回折格子の入射面に対し、前記厚さ方向と平行な方向に対して＋θ及び－θのいずれかの角度で傾斜する方向から前記円偏光を照射可能とされるＭ個の円偏光照射部が配され、
　Ｍ行目におけるＮ個の前記円偏光回転回折スイッチの前記各第２の偏光回折格子から前記厚さ方向と平行な方向に対して＋θ及び－θのいずれかの角度で傾斜する方向に出射される前記円偏光の出射方向に前記円偏光を受光可能とされるＮ個の円偏光受光部が配される請求項１から２のいずれかに記載の円偏光入出力装置。Circularly polarized light emitted from the second polarization diffraction grating of the circular polarization rotation diffraction switch in the first row and first column in a direction inclined at an angle of + θ with respect to a direction parallel to the thickness direction of the first polarization diffraction grating. The emission direction is the row direction, and the emission from the second polarization diffraction grating of the circular polarization rotation diffraction switch in the first row and first column is inclined at an angle of −θ with respect to the direction parallel to the thickness direction. M × N circular polarization rotation diffraction switches, where the circularly polarized light exit direction is a column direction, and M and N are integers of 2 or more, the incident surface of each of the first polarization diffraction gratings and the Arranged on a matrix grating of M rows and N columns with the exit surface of the second polarization diffraction grating in a parallel state,
Inclination at an angle of either + θ or −θ with respect to the direction parallel to the thickness direction with respect to the incident surface of each of the first polarization diffraction gratings of the M circular polarization rotation diffraction switches in the first row M circularly polarized light irradiating portions that are capable of irradiating the circularly polarized light from a direction to be arranged,
The light is emitted from each of the second polarization diffraction gratings of the N circularly polarized light rotation diffraction switches in the Mth row in a direction inclined at either + θ or −θ with respect to a direction parallel to the thickness direction. 3. The circularly polarized light input / output device according to claim 1, wherein N circularly polarized light receiving units capable of receiving the circularly polarized light are disposed in an emission direction of the circularly polarized light.　１行１列目の円偏光回転回折スイッチの第２の偏光回折格子から第１の偏光回折格子の厚さ方向と平行な方向に対して＋θの角度で傾斜する方向に出射される円偏光の出射方向を行の方向とし、前記１行１列目の円偏光回転回折スイッチの前記第２の偏光回折格子から前記厚さ方向と平行な方向に対して－θの角度で傾斜する方向に出射される前記円偏光の出射方向を列の方向として、Ｌを２以上の整数として２Ｌ個の円偏光回転回折スイッチが、それぞれの前記第１の偏光回折格子の入射面及び前記第２の偏光回折格子の出射面を平行な状態としてＬ行Ｌ列の菱形格子上に配され、
　１列目におけるＬ個の前記円偏光回転回折スイッチの前記各第１の偏光回折格子の入射面に対し、前記厚さ方向と平行な方向に対して＋θ及び－θのいずれかの角度で傾斜する方向から前記円偏光を照射可能とされるＬ個の円偏光照射部が配され、
　Ｌ行目におけるＬ個の前記円偏光回転回折スイッチの前記各第２の偏光回折格子から前記厚さ方向と平行な方向に対して＋θ及び－θのいずれかの角度で傾斜する方向に出射される前記円偏光の出射方向に前記円偏光を受光可能とされるＬ個の円偏光受光部が配される請求項５に記載の円偏光入出力装置。Circularly polarized light emitted from the second polarization diffraction grating of the circular polarization rotation diffraction switch in the first row and first column in a direction inclined at an angle of + θ with respect to a direction parallel to the thickness direction of the first polarization diffraction grating. The emission direction is the row direction, and the emission from the second polarization diffraction grating of the circular polarization rotation diffraction switch in the first row and first column is inclined at an angle of −θ with respect to the direction parallel to the thickness direction. 2L circular polarization rotation diffraction switches, where L is an integer greater than or equal to 2, and the incident surface of each of the first polarization diffraction gratings and the second polarization diffraction Arranged on the L rows and L columns rhombus lattice with the exit surface of the lattice in a parallel state,
Inclined at an angle of either + θ or −θ with respect to a direction parallel to the thickness direction with respect to the incident surface of each of the first polarization diffraction gratings of the L circularly polarized light diffraction switches in the first row L circularly polarized light irradiating units that can irradiate the circularly polarized light from the direction of
From the second polarization diffraction gratings of the L circular polarization rotation diffraction switches in the Lth row, the light is emitted in a direction inclined at either + θ or −θ with respect to a direction parallel to the thickness direction. The circularly polarized light input / output device according to claim 5, wherein L circularly polarized light receiving parts capable of receiving the circularly polarized light are arranged in an emission direction of the circularly polarized light.　第１の偏光回折格子の入射面及び第２の偏光回折格子の出射面の面内方向に隣接する複数の円偏光回転回折スイッチが、それぞれの前記第１の偏光回折格子及び前記第２の偏光回折格子を、一体形成された１つの部材として共有するように構成される請求項５から６のいずれかに記載の円偏光入出力装置。A plurality of circular polarization rotation diffraction switches adjacent to each other in the in-plane direction of the entrance surface of the first polarization diffraction grating and the exit surface of the second polarization diffraction grating include the first polarization diffraction grating and the second polarization polarization, respectively. The circularly polarized light input / output device according to claim 5, configured to share the diffraction grating as one integrally formed member.　第２の偏光回折格子から第１の偏光回折格子の厚さ方向と平行な方向に対して＋θ及び－θのいずれかの角度で傾斜する方向に出射される円偏光の出射方向に配され、前記円偏光を受光可能とされる円偏光受光部を有し、
　前記円偏光受光部の配置位置から前記円偏光受光部における前記円偏光の受光方向と反対方向に円偏光照射部から照射される円偏光と同一の円偏光を照射したとき、前記円偏光照射部から照射される前記円偏光とで共焦点が形成される位置に、円偏光回転回折スイッチが配される請求項１から２のいずれかに記載の円偏光入出力装置。Arranged in the emission direction of circularly polarized light emitted from the second polarization diffraction grating in a direction inclined at any angle of + θ and −θ with respect to a direction parallel to the thickness direction of the first polarization diffraction grating, A circularly polarized light receiving part capable of receiving the circularly polarized light;
When the same circularly polarized light as the circularly polarized light emitted from the circularly polarized light irradiating unit is irradiated in the direction opposite to the light receiving direction of the circularly polarized light in the circularly polarized light receiving unit from the arrangement position of the circularly polarized light receiving unit, The circularly polarized light input / output device according to claim 1, wherein a circularly polarized light rotation diffraction switch is disposed at a position where a confocal point is formed with the circularly polarized light irradiated from the circularly polarized light.　一の面が入射面とされ、前記一の面と対向する他の面が出射面とされ、角度θを３°～６０°のいずれかの角度とし、角度αを０°を超え４５°以下のいずれかの角度とし、かつ、α＋θを９０°未満として、厚さ方向に対し＋（θ＋α）及び－（θ－α）のいずれかの角度で傾斜するビーム状の円偏光が前記入射面から入射されたときに前記円偏光を前記厚さ方向に対し、前記角度αで傾斜する傾斜方向に回折させて出射面から出射可能とされる平板状の第１の偏光回折格子と、
　一の面が入射面とされ、前記一の面と対向する他の面が出射面とされるとともに前記第１の偏光回折格子と対向して配され、前記第１の偏光回折格子から前記傾斜方向で前記入射面に入射される前記円偏光に対し、電圧印加に伴うオンオフ制御により、前記円偏光の回転方向を反転させた状態及び前記回転方向を維持させた状態のいずれかの状態とし、この状態の前記円偏光を前記出射面から前記傾斜方向に出射可能とされる平板状の液晶偏光回転素子と、
　一の面が入射面とされ、前記一の面と対向する他の面が出射面とされるとともに前記液晶偏光回転素子と対向して配され、前記液晶偏光回転素子から前記傾斜方向で前記入射面に入射される前記円偏光を、前記回転方向に応じて、前記厚さ方向と平行な方向に対し＋（θ＋α）及び－（θ－α）のいずれかの角度で傾斜する方向に回折させて前記出射面から出射可能とされる平板状の第２の偏光回折格子と、を有する円偏光回転回折スイッチと、
　前記第１の偏光回折格子の前記入射面に対し、前記厚さ方向と平行な方向に対し＋（θ＋α）及び－（θ－α）のいずれかの角度で傾斜する方向から前記円偏光を照射可能とされる円偏光照射部と、
　を備えることを特徴とする円偏光入出力装置。

 
 One surface is the entrance surface, the other surface opposite to the one surface is the exit surface, the angle θ is any angle between 3 ° and 60 °, and the angle α is greater than 0 ° and less than 45 ° And α + θ is less than 90 °, and beam-like circularly polarized light tilted at any angle of + (θ + α) and − (θ−α) with respect to the thickness direction from the incident surface. A flat plate-shaped first polarization diffraction grating that is capable of diffracting the circularly polarized light in an inclined direction that is inclined at the angle α with respect to the thickness direction so that the circularly polarized light can be emitted from the exit surface when incident;
One surface is an entrance surface, the other surface facing the one surface is an exit surface, and is disposed facing the first polarization diffraction grating, and is inclined from the first polarization diffraction grating. With respect to the circularly polarized light that is incident on the incident surface in a direction, it is in a state where the rotational direction of the circularly polarized light is reversed or maintained by the on / off control accompanying voltage application, A plate-like liquid crystal polarization rotation element capable of emitting the circularly polarized light in this state from the emission surface in the tilt direction;
One surface is an entrance surface, the other surface opposite to the one surface is an exit surface, and is disposed to face the liquid crystal polarization rotator, and is incident from the liquid crystal polarization rotator in the tilt direction. The circularly polarized light incident on the surface is diffracted in a direction inclined at an angle of either + (θ + α) or − (θ−α) with respect to a direction parallel to the thickness direction according to the rotation direction. A circular polarization diffractive switch having a flat plate-like second polarization diffraction grating that can be emitted from the exit surface;
Irradiating the circularly polarized light from a direction inclined at any angle of + (θ + α) and − (θ−α) with respect to a direction parallel to the thickness direction with respect to the incident surface of the first polarization diffraction grating A circularly polarized light irradiation unit made possible;
A circularly polarized light input / output device comprising:

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