CN101320126B - Two-sided reflection movable mirror interferometer - Google Patents

Abstract

A double-sided movable reflecting mirror interferometer comprises a beam splitter, two fixed plane mirrors and a double-sided movable reflecting mirror which is a plane parallel glass sheet, and both sides of the glass sheet are plated with reflecting film; the double-sided movable reflecting mirror is parallel to the half-reflection surface of the beam splitter; a first plane mirror and a secondplane mirror are symmetrical to the half-reflection surface of the beam splitter; the double-sided movable reflecting mirror makes straight reciprocating motion along the normal direction of the half-reflection surface of the beam splitter; the optical path difference is four times longer than the displacement (relative to the position of zero optical path difference) of the double-sided movable reflecting mirror. The interferometer has compact structure, small volume and low cost, and is suitable for high resolution Fourier transform spectrometers of various spectral regions.

Description

Double-sided reflecting moving mirror interferometer

Technical field

The present invention relates to a kind of interferometer, be specifically related to a kind of double-sided reflecting moving mirror interferometer that is applied to the high resolving power Fourier transform spectrometer.

Background technology

Fourier transform spectrometer, has advantages such as high spectral resolution, high flux, hyperchannel, and influencing the greatest problem that Michelson (Michelson) interferometer uses in Fourier spectrometer is the tilt problem of plane index glass in scanning process.

Use opal mirror (cat ' s-eye retroreflector) or corner reflector (cube-corner mirrors) to replace the plane index glass can solve tilt problem well, unique shortcoming is that single cat-eye moving mirror makes or single scan angle reflecting body exist the lateral excursion problem.Another way is to use the dynamic calibration servo-drive system, but resolution is high more, and the probability of malfunction of this corrective system is just high more, and this system is very responsive to the disturbance that mechanical vibration cause.

Rotary mirror type or pendulum mirror interferometer have been eliminated the error that the plane index glass tilts to bring, and improved the stability and the reliability of instrument, but the optical path difference of its generation and corner are nonlinear relationship, only are applicable to the low-resolution spectra instrument.

Summary of the invention

The object of the present invention is to provide a kind of double-sided reflecting moving mirror interferometer, it has solved the inclination of background technology midplane index glass, single scanning opal mirror and the traversing technical matters of single scan angle reflecting body, optical path difference is 4 times of double-sided reflecting moving displacement (with respect to its zero optical path difference position), has improved precision widely with respect to Michelson interferometer in the application of Fourier transform spectrometer; Under the foozle condition identical, can obtain higher instrumental resolution with kinematic error.

Technical solution of the present invention is:

A kind of double-sided reflecting moving mirror interferometer comprises a beam splitter that is arranged on the incident beam light path; Also comprise first level crossing that is arranged on the above-mentioned beam splitter semi-reflective surface folded light beam light path and second level crossing that is arranged on the above-mentioned beam splitter semi-reflective surface transmitted light beam light path; Also comprise be arranged on the above-mentioned first flat mirror reflects beam path and the second flat mirror reflects beam path on a double-sided reflecting moving; Also comprise detector and will converge to collection mirror on the detector through the two-beam of double-sided reflecting moving reflection;

It is characterized in that:

Described double-sided reflecting moving is the plane parallel glass plate that reflectance coating is all plated on one two surface; Be parallel to each other between two surfaces of described double-sided reflecting moving plating reflectance coating, the beam splitter semi-reflective surface three; Described double-sided reflecting moving is done straight reciprocating motion along the normal direction of beam splitter semi-reflective surface; Described first level crossing and second level crossing are about beam splitter semi-reflective surface symmetry; Being centered close in the same plane of described beam splitter, first level crossing, second level crossing.

Above-mentioned double-sided reflecting moving mirror interferometer can be: described beam splitter semi-reflective surface miter angle is arranged on the incident beam light path, and this beam splitter is the plane parallel glass plate of two gummeds, and a face of cemented surface is the beam splitter semi-reflective surface; The angle of described first level crossing and second level crossing and beam splitter semi-reflective surface is 22.5 degree.

Above-mentioned double-sided reflecting moving mirror interferometer can be: described beam splitter is the right-angle prism of two gummeds, and the inclined-plane of right-angle prism is a cemented surface, and a face of cemented surface is the beam splitter semi-reflective surface; The angle of described first level crossing and second level crossing and beam splitter semi-reflective surface is 22.5 degree.

Above-mentioned double-sided reflecting moving mirror interferometer can be: described beam splitter semi-reflective surface 30 degree angles are arranged on the incident beam light path, and this beam splitter is the plane parallel glass plate of two gummeds, and a face of cemented surface is the beam splitter semi-reflective surface; The angle of described first level crossing and second level crossing and beam splitter semi-reflective surface is 30 degree.

Above-mentioned double-sided reflecting moving mirror interferometer can be: described beam splitter is the equilateral triangle prism of two gummeds, and a face of cemented surface is the beam splitter semi-reflective surface; The angle of described first level crossing and second level crossing and beam splitter semi-reflective surface is 30 degree.

Above-mentioned collection mirror is convergent lens or convergent lens group.

The invention has the advantages that:

1. this interferometer tilts insensitively to index glass, i.e. the slight inclination of double-sided reflecting moving is very little to the degree of modulation and the phase effect of gained interferogram.

2. optical path difference is 4 times of double-sided reflecting moving displacement (with respect to its zero optical path difference position), is applicable to the high-resolution spectroscopy instrument of various SPECTRAL REGION.

This interferometer structure compactness, volume is little, cost is low.

4. beam splitter is plane parallel glass plate or the right-angle prism of two gummeds or the equilateral triangle prism of two gummeds of two gummeds, thereby has improved the mechanical stability and the thermal stability of this interferometer.

Description of drawings

Fig. 1 is a structural principle synoptic diagram of the present invention (one-piece construction of isosceles right triangle).

Fig. 2 is the plane parallel glass plate light-dividing device (miter angle is arranged on the incident beam light path) of two gummeds.

Fig. 3 is the right-angle prism light-dividing device of two gummeds.

Fig. 4 is a structural principle synoptic diagram of the present invention (one-piece construction of equilateral triangle).

Fig. 5 is the plane parallel glass plate light-dividing device (30 degree angles are arranged on the incident beam light path) of two gummeds.

Fig. 6 is the equilateral triangle Prism spectroscope of two gummeds.

Embodiment

Double-sided reflecting moving mirror interferometer comprises a beam splitter, two fixing plane mirrors (i.e. first level crossing and second level crossing) and a double-sided reflecting moving; Double-sided reflecting moving is the plane parallel glass plate that reflectance coating is all plated on one two surface; Be parallel to each other between two surfaces of double-sided reflecting moving plating reflectance coating, the beam splitter semi-reflective surface three; First level crossing and second level crossing are about beam splitter semi-reflective surface symmetry; Being centered close in the same plane of beam splitter, first level crossing, second level crossing.

Embodiment 1: beam splitter semi-reflective surface miter angle is arranged on the incident beam light path, and this beam splitter is the plane parallel glass plate of two gummeds, and a face of cemented surface is the beam splitter semi-reflective surface; The angle of first level crossing and second level crossing and beam splitter semi-reflective surface is 22.5 degree.

Embodiment 2: beam splitter is the right-angle prism of two gummeds, and the inclined-plane of right-angle prism is a cemented surface, and a face of cemented surface is the beam splitter semi-reflective surface; The angle of first level crossing and second level crossing and beam splitter semi-reflective surface is 22.5 degree.

Embodiment 3: beam splitter semi-reflective surface 30 degree angles are arranged on the incident beam light path, and this beam splitter is the plane parallel glass plate of two gummeds, and a face of cemented surface is the beam splitter semi-reflective surface; The angle of first level crossing and second level crossing and beam splitter semi-reflective surface is 30 degree.

Embodiment 4: beam splitter is the equilateral triangle prism of two gummeds, and a face of cemented surface is the beam splitter semi-reflective surface; The angle of first level crossing and second level crossing and beam splitter semi-reflective surface is 30 degree.

For above-mentioned any embodiment, the parallel beam of incident reflects and transmission on the semi-reflective surface of beam splitter, and being divided into two-beam I and the II that intensity equates, light beam I is successively by directive beam splitter after first level crossing, double-sided reflecting moving coated surface one, first flat mirror reflects; Light beam II is successively by directive beam splitter after second level crossing, double-sided reflecting moving coated surface two, second flat mirror reflects; This two-beam interferes when intersecting, and converges on the detector through collecting mirror.

Optical path difference between light beam I and the II is to be produced by the straight reciprocating motion of double-sided reflecting moving, and double-sided reflecting moving is done straight reciprocating motion along the normal direction of beam splitter semi-reflective surface.

When double-sided reflecting moving displacement a, two kinds of situations are arranged: a kind of situation is that the light path of light beam I has increased 2a and the light path of light beam II has reduced 2a, so the variable quantity of optical path difference is 4a between light beam I and the light beam II; Another situation is that the light path of light beam I has reduced 2a and the light path of light beam II has increased 2a, and then the variable quantity of optical path difference still is 4a between light beam I and the light beam II.Therefore, the change amount of light path difference is 4 times of double-sided reflecting moving displacement.Pass between optical path difference x and double-sided reflecting moving displacement (with respect to its zero optical path difference position) l is

x＝4l (1)

Under ideal situation (being double-sided reflecting moving does not have inclination in motion process situation), interference strength is

I(x)＝B(σ)[1+cos(2πσx)] (2)

σ is a wave number in the formula, and B (σ) is a spectral intensity, and x is an optical path difference.

Therefore the interference strength of double-sided reflecting moving mirror interferometer and the pass between the double-sided reflecting moving displacement (with respect to its zero optical path difference position) are

I (x)=B (σ) [1+cos (8 π σ l)] (3) is when double-sided reflecting moving during at motion process medium dip θ angle, during with not run-off the straight of double-sided reflecting moving and the optical path difference x at optical axes crosspoint place₀Be benchmark, for square light beam aperture, the interference strength that obtains on the detector is

$I\left(x_0\right)=B\left(\mathrm{\σ}\right)\{1+\frac{D-L_2\tan 2\mathrm{\θ}}{D-L_1\tan 2\mathrm{\θ}}.\cos \{2\mathrm{\π\σ}(L_2-L_1)[2+\frac{2{\sin }^2\mathrm{\θ}}{\cos 2\mathrm{\θ}}-{\tan }^{2}2\mathrm{\θ}]\left\}\right\}---\left(4\right)$

D is the incident beam aperture in the formula, L₁Be the optical path length from the double-sided reflecting moving to the detector on light beam I light path, L₂Be the optical path length from the double-sided reflecting moving to the detector on light beam II light path.

Claims (6)

1. a double-sided reflecting moving mirror interferometer comprises a beam splitter that is arranged on the incident beam light path; Also comprise first level crossing that is arranged on the above-mentioned beam splitter semi-reflective surface folded light beam light path and second level crossing that is arranged on the above-mentioned beam splitter semi-reflective surface transmitted light beam light path; Also comprise be arranged on the above-mentioned first flat mirror reflects beam path and the second flat mirror reflects beam path on a double-sided reflecting moving; Also comprise detector and will converge to collection mirror on the detector through the two-beam of double-sided reflecting moving reflection;

It is characterized in that:

Described double-sided reflecting moving is the plane parallel glass plate that reflectance coating is all plated on one two surface; Be parallel to each other between two surfaces of described double-sided reflecting moving plating reflectance coating, the beam splitter semi-reflective surface three; Described double-sided reflecting moving is done straight reciprocating motion along the normal direction of beam splitter semi-reflective surface; Described first level crossing and second level crossing are about beam splitter semi-reflective surface symmetry; Being centered close in the same plane of described beam splitter, first level crossing, second level crossing.

2. double-sided reflecting moving mirror interferometer according to claim 1, it is characterized in that: described beam splitter semi-reflective surface miter angle is arranged on the incident beam light path, this beam splitter is the plane parallel glass plate of two gummeds, and a face of cemented surface is the beam splitter semi-reflective surface; The angle of described first level crossing and second level crossing and beam splitter semi-reflective surface is 22.5 degree.

3. double-sided reflecting moving mirror interferometer according to claim 1 is characterized in that: described beam splitter is the right-angle prism of two gummeds, and the inclined-plane of right-angle prism is a cemented surface, and a face of cemented surface is the beam splitter semi-reflective surface; The angle of described first level crossing and second level crossing and beam splitter semi-reflective surface is 22.5 degree.

4. double-sided reflecting moving mirror interferometer according to claim 1, it is characterized in that: described beam splitter semi-reflective surface 30 degree angles are arranged on the incident beam light path, this beam splitter is the plane parallel glass plate of two gummeds, and a face of cemented surface is the beam splitter semi-reflective surface; The angle of described first level crossing and second level crossing and beam splitter semi-reflective surface is 30 degree.

5. double-sided reflecting moving mirror interferometer according to claim 1 is characterized in that: described beam splitter is the equilateral triangle prism of two gummeds, and a face of cemented surface is the beam splitter semi-reflective surface; The angle of described first level crossing and second level crossing and beam splitter semi-reflective surface is 30 degree.

6. according to the arbitrary described double-sided reflecting moving mirror interferometer of claim 2～5, it is characterized in that: described collection mirror is convergent lens or convergent lens group.

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