CN100401028C - All-fiber cavity ring-down absorption spectrum detection sensor device - Google Patents

Abstract

Translated fromChinese

一种全光纤腔衰荡吸收光谱检测传感装置，其结构是它依次由光源及其第一驱动器、光纤谐振腔、光电探测器和信号采集处理系统连接而构成。该装置具有腔镜反射率高、谐振腔精细度高、反射带宽宽、光谱测量范围宽、光功率耦合效率高、测量灵敏度高和结构简单的优点。

An all-fiber cavity ring-down absorption spectrum detection sensor device is structured to be sequentially connected by a light source and its first driver, a fiber resonant cavity, a photodetector and a signal acquisition and processing system. The device has the advantages of high cavity mirror reflectivity, high resonant cavity fineness, wide reflection bandwidth, wide spectrum measurement range, high optical power coupling efficiency, high measurement sensitivity and simple structure.

Description

Translated fromChinese

全光纤腔衰荡吸收光谱检测传感装置All-fiber cavity ring-down absorption spectrum detection sensor device

技术领域technical field

本发明是一种采用腔衰荡原理的光纤检测传感技术。本发明属于光学测量传感技术领域，主要应用于应变、压力、电流等物理量以及液体、气体浓度和折射率等化学量的传感检测。The invention is an optical fiber detection and sensing technology adopting the principle of cavity ring down. The invention belongs to the technical field of optical measurement and sensing, and is mainly applied to the sensing and detection of physical quantities such as strain, pressure and current, and chemical quantities such as liquid and gas concentration and refractive index.

背景技术Background technique

光纤传感器由于具有抗电磁干扰能力强、灵敏度高、电绝缘性好、安全可靠、耐腐蚀、可构成光纤传感网等诸多优点，因而在工业、农业、生物医疗、国防等各领域均有广阔应用前景。Optical fiber sensors have many advantages such as strong anti-electromagnetic interference, high sensitivity, good electrical insulation, safety and reliability, corrosion resistance, and can form an optical fiber sensor network, so they have broad applications in various fields such as industry, agriculture, biomedicine, and national defense. Application prospect.

腔衰荡光谱技术(Cavity Ring Down Spectroscopy)是近几年发展起来的的一种吸收光谱新型检测技术。腔衰荡光谱技术基本原理是：测量光脉冲入射到由两个高反射镜组成的高精细度光学谐振腔(一般地，高反射镜的反射率R≥0.9999)，一小部分(1-R，约10^-5)的入射光通过其中一个高反射镜耦合进入光学谐振腔，在腔中来回反射，在腔镜反射损耗、腔内固有损耗以及腔内被测物质(如气体、液体等化学吸收体)吸收损耗的作用下，腔内光子数在来回振荡中慢慢衰减(即衰荡，ringdown)。腔内光脉冲每来回反射一次，一小部分(1-R，约10^-5)腔内光子通过后腔镜传输至腔外并由一个高灵敏度光电探测器探测，探测器的输出将呈现指数衰减，其时间常数τ决定于腔镜的反射率和被测物质的吸收大小，如公式1所示，Cavity Ring Down Spectroscopy (Cavity Ring Down Spectroscopy) is a new type of absorption spectroscopy detection technology developed in recent years. The basic principle of Cavity Ring-Down Spectroscopy is: to measure the incident light pulse into a high-precision optical resonant cavity composed of two high-reflection mirrors (generally, the reflectivity of the high-reflection mirror is R≥0.9999), a small part (1-R , about 10^-5 ), the incident light is coupled into the optical resonant cavity through one of the high reflection mirrors, reflected back and forth in the cavity, and the reflection loss of the cavity mirror, the inherent loss in the cavity, and the measured substances in the cavity (such as gases, liquids, etc.) Absorber) under the action of absorption loss, the number of photons in the cavity slowly decays in the back-and-forth oscillation (that is, ringdown). Every time the light pulse in the cavity is reflected back and forth, a small part (1-R, about 10^-5 ) of the photons in the cavity are transmitted to the outside of the cavity through the rear cavity mirror and detected by a high-sensitivity photodetector, and the output of the detector will show an exponential Attenuation, its time constant τ is determined by the reflectivity of the cavity mirror and the absorption of the measured substance, as shown informula 1,

$\mathrm{<span><span>\&tau;</span>\&tau;</span>}<span><span>=</span>=</span>\frac{{\mathrm{<span><span>Ln</span>ln</span>}}_{\mathrm{<span><span>eff</span>eff</span>}}}{\mathrm{<span><span>c</span>c</span>}<span><span>[</span>[</span><span><span>(</span>(</span>\mathrm{<span><span>1</span>1</span>}<span><span>-</span>-</span>\mathrm{<span><span>R</span>R</span>}<span><span>)</span>)</span><span><span>+</span>+</span>\mathrm{<span><span>l</span>l</span>}<span><span>]</span>]</span>}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>1</span>1</span>}<span><span>)</span>)</span>$

式中，L为光学谐振腔长度，n_eff为腔内有效折射率，R为腔镜的反射率，l为腔内被测物质引起的吸收损耗。由此通过测量光衰减的时间常数，来探测被测物质的吸收大小，并进而可根据比尔朗伯特定理获得其浓度，如公式2In the formula, L is the length of the optical resonant cavity, n_eff is the effective refractive index in the cavity, R is the reflectivity of the cavity mirror, and l is the absorption loss caused by the measured substance in the cavity. Therefore, by measuring the time constant of light attenuation, the absorption of the measured substance can be detected, and its concentration can be obtained according to Bill Lambert's theorem, as shown informula 2

l＝αL＝σLC    (2)l=αL=σLC (2)

这里，α为被测物质的吸收系数，σ为被测物质的吸收截面，C为被测物质的浓度。Here, α is the absorption coefficient of the measured substance, σ is the absorption cross section of the measured substance, and C is the concentration of the measured substance.

腔衰荡光谱技术的主要优点在于：1.采用高精细度光学谐振腔，极大地增加了吸收光程，大大提高了测量的灵敏度；2.通过测量腔内脉冲的衰减时间常数，对输入光强波动不敏感，是一种对腔内损耗的直接测量，无需转换校准。The main advantages of cavity ring-down spectroscopy technology are: 1. Using high-precision optical resonant cavity, which greatly increases the absorption optical path and greatly improves the sensitivity of measurement; 2. By measuring the decay time constant of the pulse in the cavity, the input light Insensitive to strong fluctuations, it is a direct measurement of intracavity losses without conversion calibration.

为了将腔衰荡光谱原理引入光纤传感领域中，结合两者的优点，形成新型光纤腔衰荡传感技术，人们已经提出了若干技术方案。在先技术之一[Tuomo von Lerber等，APPLIED OPTICS，2002，41：3567-3575]，是在1米长的光纤的两个光纤连接器端面进行抛光，镀上高反射率介质膜构成高精细度光纤谐振腔，观察到了1微秒左右的腔衰荡时间，并进行了光纤弯曲损耗和光纤倏逝波传感实验，获得了初步成功。但这一方法的缺点是在光纤端面上进行抛光和镀高反射率介质膜的技术复杂，成本高，而且高反射率介质膜的带宽受限，一般在10纳米左右，限制了腔衰荡的光谱测量范围。在先技术之二[Manish Gupta等，OPTICSLETTERS，2002，27：1878-1881]，是采用两个高反射率光纤布拉格光栅构成高精细度光纤谐振腔，在10米腔长的情况下获得了2微秒左右的腔衰荡时间。这一方法的缺点是作为高反射腔镜的两个光纤光栅的波长和带宽必须很好的匹配，另外，该方法的光谱测量范围受光纤光栅的反射带宽限制，一般在几个纳米左右。同时，上述在先技术还有一个共同的缺点：入射光脉冲耦合进入光纤谐振腔的效率取决于输入腔镜的反射率，反射率越高，耦合效率越低，进入光电探测器的光强越弱，而光电探测器都存在探测下限，另一方面从公式1知道，腔镜反射率越高，腔衰荡时间就越长，测量灵敏度就越高。也就是说存在腔镜反射率和输入耦合效率的矛盾，这就限制了光纤腔衰荡传感装置测量灵敏度的进一步提高。In order to introduce the principle of cavity ring-down spectroscopy into the field of optical fiber sensing, and combine the advantages of the two to form a new optical fiber cavity ring-down sensing technology, several technical solutions have been proposed. One of the prior technologies [Tuomo von Lerber et al., APPLIED OPTICS, 2002, 41: 3567-3575] is to polish the end faces of two optical fiber connectors of a 1-meter-long optical fiber, and plate a high-reflectivity dielectric film to form a high-precision optical fiber. The optical fiber resonant cavity was observed, and the cavity ring-down time of about 1 microsecond was observed, and the optical fiber bending loss and optical fiber evanescent wave sensing experiments were carried out, and preliminary success was obtained. However, the disadvantage of this method is that the technology of polishing and coating the high-reflectivity dielectric film on the fiber end face is complicated, the cost is high, and the bandwidth of the high-reflectivity dielectric film is limited, generally around 10 nanometers, which limits the ring-down of the cavity. Spectral measurement range. The second prior technology [Manish Gupta et al., OPTICSLETTERS, 2002, 27: 1878-1881] is to use two high-reflectivity fiber Bragg gratings to form a high-definition fiber resonator cavity, and obtained 2 Cavity ring down time on the order of microseconds. The disadvantage of this method is that the wavelengths and bandwidths of the two fiber gratings used as high-reflection cavity mirrors must be well matched. In addition, the spectral measurement range of this method is limited by the reflection bandwidth of the fiber grating, which is generally around several nanometers. At the same time, the above-mentioned prior art also has a common shortcoming: the efficiency of coupling the incident light pulse into the fiber resonator depends on the reflectivity of the input cavity mirror, the higher the reflectivity, the lower the coupling efficiency, and the higher the light intensity entering the photodetector. Weak, and photodetectors have lower detection limits. On the other hand, it is known fromformula 1 that the higher the reflectivity of the cavity mirror, the longer the ring-down time of the cavity, and the higher the measurement sensitivity. That is to say, there is a contradiction between the reflectivity of the cavity mirror and the input coupling efficiency, which limits the further improvement of the measurement sensitivity of the optical fiber cavity ring-down sensing device.

发明内容Contents of the invention

为了克服上述在先技术的缺点和不足，本发明提出一种采用光纤环形镜构成的全光纤腔衰荡吸收光谱检测传感装置，该装置应具有腔镜反射率高、谐振腔精细度高、反射带宽宽、光谱测量范围宽、测量灵敏度高、结构简单的优点。In order to overcome the shortcomings and deficiencies of the above-mentioned prior art, the present invention proposes an all-fiber cavity ring-down absorption spectrum detection and sensing device that adopts a fiber optic loop mirror. The device should have high cavity mirror reflectivity, high resonant cavity precision, It has the advantages of wide reflection bandwidth, wide spectrum measurement range, high measurement sensitivity and simple structure.

本发明的技术解决方案：Technical solution of the present invention:

一种全光纤腔衰荡吸收光谱检测传感装置，依次由光源及其第一驱动器、光纤谐振腔、光电探测器和信号采集处理系统连接而构成，其特点是所述的光纤谐振腔由第一光纤环形镜通过光纤与第二光纤环形镜相连构成；所述的第一光纤环形镜由第一光纤耦合器同侧的第三端口和第四端口与第一光纤环路连接构成；所述的第二光纤环形镜由第二光纤耦合器同侧的第三端口和第四端口与第二光纤环路连接构成；所述的光源的输出端与第一光纤耦合器的第一端口相连，第一光纤耦合器的第二端口与所述的光纤的一端相连；该光纤的另一端连接第二光纤耦合器的第一端口，该第二光纤耦合器的第二端口经光电探测器和信号采集处理系统相连。An all-fiber cavity ring-down absorption spectrum detection and sensing device is composed of a light source and its first driver, an optical fiber resonant cavity, a photodetector and a signal acquisition and processing system connected in sequence. A fiber optic loop mirror is formed by connecting the second fiber optic loop mirror through an optical fiber; the first fiber optic loop mirror is formed by connecting the third port and the fourth port on the same side of the first fiber coupler to the first fiber loop loop; The second fiber loop mirror is formed by connecting the third port and the fourth port on the same side of the second fiber coupler to the second fiber loop; the output end of the light source is connected to the first port of the first fiber coupler, The second port of the first optical fiber coupler is connected to one end of the optical fiber; the other end of the optical fiber is connected to the first port of the second optical fiber coupler, and the second port of the second optical fiber coupler is passed through the photodetector and signal The collection and processing system is connected.

一种全光纤腔衰荡吸收光谱检测传感装置，依次由光源及其第一驱动器、光纤谐振腔、光电探测器和信号采集处理系统连接而构成，其特点是所述的光纤谐振腔，由一光纤环形镜开关通过光纤与第二光纤环形镜相连构成；所述的第二光纤环形镜由第二光纤耦合器同侧的第三端口和第四端口与第二光纤环路连接构成；所述的光源的输出端与该光纤环形镜开关的第一端口相连；该光纤环形镜开关的第二端口与所述的光纤的一端相连；该光纤另一端连接第二光纤耦合器的第一端口，该第二光纤耦合器的第二端口经光电探测器和信号采集处理系统相连。An all-fiber cavity ring-down absorption spectrum detection and sensing device is composed of a light source and its first driver, an optical fiber resonant cavity, a photodetector and a signal acquisition and processing system connected in sequence, and is characterized in that the optical fiber resonant cavity is composed of A fiber optic loop mirror switch is formed by connecting an optical fiber to a second fiber optic loop mirror; the second fiber optic loop mirror is formed by connecting the third port and the fourth port on the same side of the second fiber coupler to the second fiber loop loop; The output end of the light source is connected to the first port of the fiber optic loop mirror switch; the second port of the fiber optic loop mirror switch is connected to one end of the optical fiber; the other end of the fiber is connected to the first port of the second fiber optic coupler , the second port of the second optical fiber coupler is connected to the signal acquisition and processing system via the photodetector.

所述的光纤环形镜开关的构成是：由第三光纤耦合器同侧的第三端口和第四端口与第三光纤环路的两端连接，在第三光纤环路偏离中心位置接入光调制单元，该光调制单元设有第一驱动电源，该第一驱动电源与所述的第一驱动器相连并同步运转。The composition of the optical fiber loop mirror switch is: the third port and the fourth port on the same side of the third optical fiber coupler are connected to the two ends of the third optical fiber loop, and the optical fiber loop is connected to the off-center position of the third optical fiber loop. A modulation unit, the light modulation unit is provided with a first driving power supply, which is connected to the first driver and operates synchronously.

所述的光纤环形镜开关的构成是：由第三光纤耦合器同侧的第三端口和第四端口与第三光纤环路的两端连接，在第三光纤环路偏离中心位置接入一个半导体光放大器和第三光纤耦合器，所述的半导体光放大器具有第二驱动电源，所述的第四光纤耦合器的第三端口连接一控制激光器，该控制激光器连接第三驱动电源，所述的第三驱动电源与所述的第一驱动电源连接并同步工作。The composition of the optical fiber loop mirror switch is: the third port and the fourth port on the same side of the third optical fiber coupler are connected to the two ends of the third optical fiber loop, and a A semiconductor optical amplifier and a third optical fiber coupler, the semiconductor optical amplifier has a second drive power supply, the third port of the fourth optical fiber coupler is connected to a control laser, and the control laser is connected to a third drive power supply, the The third driving power is connected with the first driving power and works synchronously.

所述的光纤环形镜开关的构成是：由第三光纤耦合器同侧的第三端口和第四端口与第三光纤环路的两端连接，在第三光纤环路中偏离中心位置接入一段高非线性光纤和第四光纤耦合器，该第四光纤耦合器连接一超短脉冲激光器，该超短脉冲激光器在脉冲发生器的驱动下工作，该脉冲发生器与第一驱动器相连并同步工作。The composition of the optical fiber loop mirror switch is as follows: the third port and the fourth port on the same side of the third optical fiber coupler are connected to the two ends of the third optical fiber loop, and the off-center position of the third optical fiber loop is connected to the A section of highly nonlinear optical fiber and a fourth fiber coupler, the fourth fiber coupler is connected with an ultrashort pulse laser, and the ultrashort pulse laser works under the drive of a pulse generator, which is connected and synchronized with the first driver Work.

所述的光纤环形镜开关的构成是：由第三光纤耦合器同侧的第三端口和第四端口与第三光纤环路的两端连接，在第三光纤环路中偏离中心位置接入一波分复用器和一段有源光纤，所述的波分复用器的第三端连接一泵浦激光器，该泵浦激光器设有第二驱动器，所述的第二驱动器与第一驱动器相连并同步工作。The composition of the optical fiber loop mirror switch is as follows: the third port and the fourth port on the same side of the third optical fiber coupler are connected to the two ends of the third optical fiber loop, and the off-center position of the third optical fiber loop is connected to the A wavelength division multiplexer and a section of active optical fiber, the third end of the wavelength division multiplexer is connected to a pump laser, the pump laser is provided with a second driver, the second driver and the first driver Connect and work in sync.

本发明的特点和优点如下：Features and advantages of the present invention are as follows:

1、本发明全光纤腔衰荡吸收光谱检测传感装置，与在先技术相比，具有腔镜反射率高、谐振腔精细度高的优点，而且反射带宽很宽，可达几十纳米，具有光谱测量范围宽的优点；1. Compared with the prior art, the all-fiber cavity ring-down absorption spectrum detection and sensing device of the present invention has the advantages of high cavity mirror reflectivity and high resonant cavity precision, and the reflection bandwidth is very wide, up to tens of nanometers. It has the advantages of wide spectral measurement range;

2、本发明的全光纤腔衰荡吸收光谱检测传感装置，与在先技术相比，腔镜反射率可以动态调制，从而在保证高精细度的条件下，又可以获得高的光功率耦合效率，降低了光电探测器的要求，能够获得更高的测量灵敏度；2. Compared with the prior art, the all-fiber cavity ring-down absorption spectrum detection and sensing device of the present invention can dynamically modulate the reflectivity of the cavity mirror, so that high optical power coupling can be obtained under the condition of ensuring high precision. Efficiency, reducing the requirements for photodetectors, enabling higher measurement sensitivity;

3、本发明的全光纤腔衰荡吸收光谱检测传感装置，与在先技术相比，结构简单，制作容易，成本低廉。3. Compared with the prior art, the all-fiber cavity ring-down absorption spectrum detection and sensing device of the present invention has simple structure, easy fabrication and low cost.

附图说明Description of drawings

图1本发明实施例一：采用光纤环形镜构成高精细度光纤谐振腔的光纤腔衰荡传感装置示意图；Fig. 1Embodiment 1 of the present invention: a schematic diagram of a fiber optic cavity ring-down sensing device that uses a fiber optic loop mirror to form a high-precision fiber optic resonator cavity;

图2本发明实施例二：采用高速光纤环形镜光开关作为高精细度光纤谐振腔输入腔镜的光纤腔衰荡传感装置示意图；Fig. 2Embodiment 2 of the present invention: a schematic diagram of an optical fiber cavity ring-down sensing device using a high-speed optical fiber ring mirror optical switch as a high-precision optical fiber resonator input cavity mirror;

图3本发明实施例三：采用半导体光放大器构成的非线性光纤环形镜实现高反射和高透过特性高速切换的光纤腔衰荡传感装置示意图；Fig. 3Embodiment 3 of the present invention: a schematic diagram of an optical fiber cavity ring-down sensing device for high-speed switching between high reflection and high transmission characteristics using a nonlinear optical fiber loop mirror composed of a semiconductor optical amplifier;

图4本发明实施例四：采用高非线性光纤构成的非线性光纤环形镜实现高反射和高透过特性高速切换光纤腔衰荡传感装置示意图；Fig. 4Embodiment 4 of the present invention: a schematic diagram of a high-speed switching optical fiber cavity ring-down sensing device with high reflection and high transmission characteristics using a nonlinear optical fiber loop mirror composed of a highly nonlinear optical fiber;

图5本发明实施例五：采用光纤放大器构成的非线性光纤环形镜实现高反射和高透过特性高速切换的光纤腔衰荡传感装置示意图。Fig. 5Embodiment 5 of the present invention: a schematic diagram of an optical fiber cavity ring-down sensing device that uses a nonlinear optical fiber loop mirror composed of an optical fiber amplifier to realize high-speed switching between high reflection and high transmission characteristics.

具体实施方式Detailed ways

下面结合附图和实施例对本发明作进一步说明。The present invention will be further described below in conjunction with drawings and embodiments.

实施例一Embodiment one

如图1所示，全光纤腔衰荡吸收光谱检测传感装置，它依次由光源1及其第一驱动器11、光纤谐振腔、光电探测器5和信号采集处理系统6连接而构成。As shown in FIG. 1 , the all-fiber cavity ring-down absorption spectrum detection sensor device is composed of alight source 1 and itsfirst driver 11 , a fiber resonant cavity, aphotodetector 5 and a signal acquisition andprocessing system 6 connected in sequence.

所述的光纤谐振腔由第一光纤环形镜2通过光纤4与第二光纤环形镜3相连构成；所述的第一光纤环形镜2由第一光纤耦合器21同侧的第三端口213和第四端口214与第一光纤环路22连接构成；所述的第二光纤环形镜3由第二光纤耦合器31同侧的第三端口313和第四端口314与第二光纤环路32连接构成；所述的光源1的输出端与第一光纤耦合器21的第一端口211相连，第一光纤耦合器21的第二端口212与光纤4的一端相连；该光纤4另一端连接第二光纤耦合器31的第一端口311，该第二光纤耦合器31的第二端口312经光电探测器5和信号采集处理系统6相连。Described fiber resonant cavity is formed by the first fiberoptic loop mirror 2 being connected with the second fiberoptic loop mirror 3 throughoptical fiber 4; Described first fiberoptic loop mirror 2 is formed by thethird port 213 on the same side of thefirst fiber coupler 21 and Thefourth port 214 is connected to thefirst fiber loop 22; the secondfiber loop mirror 3 is connected to thesecond fiber loop 32 by thethird port 313 and thefourth port 314 on the same side of thesecond fiber coupler 31 Composition; the output end of thelight source 1 is connected to thefirst port 211 of thefirst fiber coupler 21, and thesecond port 212 of thefirst fiber coupler 21 is connected to one end of theoptical fiber 4; the other end of theoptical fiber 4 is connected to the second Thefirst port 311 of thefiber coupler 31 and thesecond port 312 of thesecond fiber coupler 31 are connected to the signal acquisition andprocessing system 6 via thephotodetector 5 .

本实施例是基于采用光纤环形镜作为光纤谐振腔，构成宽带高精细度光纤谐振腔的光纤腔衰荡传感装置。将3dB第一光纤耦合器21的同侧的两端口213和214同第一光纤环路22连接构成第一光纤环形镜2。将3dB第二光纤耦合器31的同侧的两端口313和314同第二光纤环路32连接构成第二光纤环形镜3。第一光纤耦合器21的另一侧第二端口212连接到光纤4。该光纤4的另外一端连接到第二光纤耦合器31另一侧第一端口311。从光源1发出的光波注入第一光纤耦合器21的第一端口211，从第三端口213和第四端口214分束输出，以顺时针和逆时针方向经过第一光纤环路22，回到第一光纤耦合器21，并在其中发生干涉；再从第一端口211和第二端口212输出。由于干涉的结果，从第二端口212输出的光波强度为I₁＝(1-2η)I₀exp(-αl)；而从第一端口211向入射方向反射的光波强度可以表示为：I_1B＝4η(1-η)I₀exp(-αl)。式中I₀为入射光强；(1-η)∶η为光纤耦合器的分束比；l为光纤环路的长度；α为光纤环路的损耗系数。因此，用分束比为1∶1的3dB第一光纤耦合器21构成的光纤环形镜2，理想反射率可以达到100％。通过调整第一光纤耦合器21的分束比，可以获得腔衰荡所要求的反射率，比如达到99.9％以上。而且，具有宽带特性分束比的光纤耦合器已经商品化，因此可以获得反射带宽达到几十个纳米的光纤环形镜。第二光纤环形镜3具有相同的性质。这样，第一光纤环形镜2、第二光纤环形镜3和光纤4构成一个光脉冲在其中来回振荡的高精细度谐振腔。光源1发出的光脉冲进入第一光纤耦合器21的第一端口211，由于第一光纤环形镜2的高反射率，一小部分透射光耦合进入由第一光纤环形镜2、光纤4和第二光纤环形镜3构成的宽带高精细度光纤谐振腔，在腔内来回反射并慢慢振荡衰减(即衰荡)。腔内光脉冲每来回反射一次，一小部分腔内光子通过第二光纤环形镜3从第二光纤耦合器31的第二端口312传输至腔外并由光电探测器5探测。光电探测器5的输出电信号进入信号采集处理系统6。根据公式1，通过分析测量到的腔衰荡时间常数，可以实现对腔内损耗的高精度测量。This embodiment is based on using a fiber optic loop mirror as a fiber resonator to form a fiber cavity ring-down sensing device with a broadband high-definition fiber resonator. Connect the twoports 213 and 214 on the same side of the 3dBfirst fiber coupler 21 with thefirst fiber loop 22 to form the firstfiber loop mirror 2 . Connect the twoports 313 and 314 on the same side of the 3dBsecond fiber coupler 31 with thesecond fiber loop 32 to form the secondfiber loop mirror 3 . Thesecond port 212 on the other side of thefirst fiber coupler 21 is connected to theoptical fiber 4 . The other end of theoptical fiber 4 is connected to thefirst port 311 on the other side of thesecond fiber coupler 31 . The light wave sent from thelight source 1 is injected into thefirst port 211 of the firstoptical fiber coupler 21, and is output from thethird port 213 and thefourth port 214, and passes through the firstoptical fiber loop 22 in a clockwise and counterclockwise direction, and returns to Thefirst fiber coupler 21 , and interference occurs therein; then output from thefirst port 211 and thesecond port 212 . As a result of interference, the light wave intensity output from thesecond port 212 is I₁ =(1-2η)I₀ exp(-αl); and the light wave intensity reflected from thefirst port 211 to the incident direction can be expressed as: I_1B =4η(1-η)I₀ exp(-αl). In the formula, I₀ is the incident light intensity; (1-η): η is the beam splitting ratio of the fiber coupler; l is the length of the fiber loop; α is the loss coefficient of the fiber loop. Therefore, the ideal reflectivity of thefiber loop mirror 2 formed by the 3dBfirst fiber coupler 21 with a beam splitting ratio of 1:1 can reach 100%. By adjusting the beam splitting ratio of thefirst fiber coupler 21 , the reflectivity required for cavity ring down can be obtained, for example, it can reach more than 99.9%. Moreover, fiber optic couplers with broadband characteristic beam splitting ratios have been commercialized, so fiber loop mirrors with reflection bandwidths of tens of nanometers can be obtained. The secondfiber loop mirror 3 has the same properties. In this way, the firstfiber loop mirror 2, the secondfiber loop mirror 3 and theoptical fiber 4 constitute a high-precision resonant cavity in which light pulses oscillate back and forth. The light pulse sent by thelight source 1 enters thefirst port 211 of thefirst fiber coupler 21. Due to the high reflectivity of the first fiberoptic loop mirror 2, a small part of the transmitted light is coupled into the first fiberoptic loop mirror 2, theoptical fiber 4 and the first fiber loop mirror. The broadband high-precision fiber resonant cavity formed by the two optical fiber loop mirrors 3 reflects back and forth in the cavity and slowly oscillates and attenuates (that is, rings down). Every time the intracavity light pulse is reflected back and forth, a small part of intracavity photons are transmitted from thesecond port 312 of thesecond fiber coupler 31 to the outside of the cavity through the secondfiber loop mirror 3 and detected by thephotodetector 5 . The output electrical signal of thephotodetector 5 enters the signal acquisition andprocessing system 6 . According toEquation 1, by analyzing the measured cavity ring-down time constant, high-precision measurement of intra-cavity loss can be realized.

本实施例具有腔镜反射率高、光谱测量范围宽的优点，而且光纤环形镜是由3dB光纤耦合器构成，成本非常低。This embodiment has the advantages of high reflectivity of the cavity mirror and wide spectrum measurement range, and the fiber loop mirror is composed of a 3dB fiber coupler, and the cost is very low.

实施例二Embodiment two

如图2所示，本发明全光纤腔衰荡吸收光谱检测传感装置，所述的光纤谐振腔由一环形镜开关7的第二端口712通过光纤4与第二光纤耦合器31的第一端口311相连构成，所述的第二光纤环形镜3由第二光纤耦合器31同侧的第三端口313和第四端口314同第二光纤环路32连接构成；所述的光源1的输出端与该环形镜开关7的第一端口711相连；该环形镜开关7的第二端口712与所述的光纤4的一端相连；该光纤4另一端连接第二光纤耦合器31的第一端口311，该第二光纤耦合器31的第二端口312经光电探测器5和信号采集处理系统6相连。所述的环形镜开关7的构成是：所述的第三光纤耦合器71同侧的第三端口713和第四端口714与第三光纤环路72的两端连接，在第三光纤环路72偏离中心位置接入光调制单元73，该光调制单元73设有第一驱动电源74，该第一驱动电源74与所述的第一驱动器11相连并同步运转。光调制单元73由第一驱动电源74驱动控制。As shown in Figure 2, the all-fiber cavity ring-down absorption spectrum detection sensor device of the present invention, the described fiber resonant cavity is passed through thesecond port 712 of aring mirror switch 7 through thefirst port 712 of theoptical fiber 4 and thesecond fiber coupler 31. Theports 311 are connected to form, and the secondfiber loop mirror 3 is formed by connecting thethird port 313 and thefourth port 314 on the same side of thesecond fiber coupler 31 with thesecond fiber loop 32; the output of thelight source 1 The end is connected with thefirst port 711 of thering mirror switch 7; thesecond port 712 of thering mirror switch 7 is connected with one end of theoptical fiber 4; the other end of theoptical fiber 4 is connected with the first port of thesecond fiber coupler 31 311 , thesecond port 312 of the secondoptical fiber coupler 31 is connected to the signal acquisition andprocessing system 6 via thephotodetector 5 . The composition of thering mirror switch 7 is: thethird port 713 and thefourth port 714 on the same side of the thirdoptical fiber coupler 71 are connected to the two ends of the thirdoptical fiber loop 72, and the thirdoptical fiber loop 72 is connected to thelight modulation unit 73 off-center, and thelight modulation unit 73 is provided with a firstdriving power supply 74, which is connected to thefirst driver 11 and operates synchronously. Thelight modulation unit 73 is driven and controlled by the firstdriving power supply 74 .

接入了调制单元73的光纤环形镜72是一个反射率可调的光纤环形镜开关。从而构成一个高输入耦合效率、宽带、高精细度的光纤谐振腔的光纤谐振腔，实现高灵敏度和高精度的腔衰荡检测传感。The fiberoptic loop mirror 72 connected to themodulation unit 73 is a fiber optic loop mirror switch with adjustable reflectivity. Thus, a fiber resonant cavity with high input coupling efficiency, broadband and high precision is formed to realize high-sensitivity and high-precision cavity ring-down detection and sensing.

在该结构中，将第三光纤耦合器71同侧的第三端口713和第四端口714通过光纤环路72连接，构成光纤环形镜。在环中接入光调制单元73，形成可控光纤环形镜7。该可控光纤环形镜7的工作特征是：在光开关单元73处于“全通”状态时，从第一端口711或第二端口712输入到可控光纤环形镜7的光信号，将分别反射回原第一端口711或第二端口712。此时，可控光纤环形镜7相当于一个高反射镜，它与光纤4和光纤环形镜3构成一个高精细度的光纤谐振腔。在光调制单元73处于“全反射”状态时，从第一端口711输入到可控光纤环形镜7的光脉冲将从另一端口712输出，注入光纤4。此时可控光纤环形镜7相当于一个透过率很高的耦合器，它可以将光脉冲功率高效率地耦合进谐振腔。一旦光脉冲注入光纤4，立即切换光开关单元的状态，使光纤谐振腔恢复到高精细度状态。在该结构中，第二光纤环形镜3的构成和作用原理与图1中的第二光纤环形镜3相同。这样，可控光纤环形镜7、光纤4和光纤环形镜3就构成了一个高输入耦合效率、宽带、高精细度的光纤谐振腔。In this structure, thethird port 713 and thefourth port 714 on the same side of thethird fiber coupler 71 are connected through thefiber loop 72 to form a fiber loop mirror. Alight modulation unit 73 is connected in the ring to form a controllable fiberoptic ring mirror 7 . The working characteristic of this controllable fiberoptic loop mirror 7 is: when theoptical switch unit 73 is in the "all-through" state, the optical signal input to the controllable fiberoptic loop mirror 7 from thefirst port 711 or thesecond port 712 will be reflected respectively Return to the originalfirst port 711 orsecond port 712 . At this time, the controllable fiberoptic loop mirror 7 is equivalent to a high reflection mirror, and it forms a high-precision fiber resonator cavity with theoptical fiber 4 and the fiberoptic loop mirror 3 . When thelight modulation unit 73 is in the “total reflection” state, the light pulse input from thefirst port 711 to the controllable fiberoptic loop mirror 7 will be output from theother port 712 and injected into theoptical fiber 4 . At this time, the controllable fiberoptic loop mirror 7 is equivalent to a coupler with high transmittance, which can efficiently couple the optical pulse power into the resonant cavity. Once the light pulse is injected into theoptical fiber 4, the state of the optical switch unit is switched immediately, so that the fiber resonator is restored to a high-definition state. In this structure, the composition and working principle of the second fiberoptic loop mirror 3 are the same as those of the second fiberoptic loop mirror 3 in FIG. 1 . In this way, the controllablefiber loop mirror 7, thefiber 4 and thefiber loop mirror 3 constitute a fiber resonator with high input coupling efficiency, broadband, and high precision.

本实施例的工作过程如下：光源1发出的光脉冲进入第三光纤耦合器71的第一端口711，可控光纤环形镜光7的光调制单元73在第一驱动电源74的驱动下，同步地切换到高透过率状态。切换的持续时间足够短，在输入至光纤4中的光脉冲经第二二光纤环形镜3反射回光纤4，到达可控光纤环形镜7的第二端口712之前，可控光纤环形镜7已切换为高反射状态。此后，光脉冲就在由可控光纤环形镜7、光纤4和第二光纤环形镜3构成的谐振腔内来回反射并慢慢振荡衰减(即衰荡)。腔内光脉冲每来回反射一次，一小部分腔内光子通过第二光纤环形镜3的光纤耦合器31的第二端口312传输至腔外，并由光电探测器5探测。光电探测器5的输出电信号进入信号采集处理系统6。根据公式1，通过分析测量到的腔衰荡时间常数，可以实现对腔内损耗的高精度测量。The working process of the present embodiment is as follows: the light pulse sent by thelight source 1 enters thefirst port 711 of thethird fiber coupler 71, and thelight modulation unit 73 of the controllable optical fiberring mirror light 7 is driven by the firstdriving power supply 74 to synchronize switch to a high transmittance state. The duration of switching is short enough that the controllable fiberoptic loop mirror 7 has completed before the light pulse input into thefiber optic 4 is reflected back to thefiber optic 4 by the second fiberoptic loop mirror 3 and reaches thesecond port 712 of the controllable fiberoptic loop mirror 7. Switch to high reflection state. Thereafter, the light pulse is reflected back and forth in the resonant cavity formed by the controllable opticalfiber loop mirror 7, theoptical fiber 4 and the second opticalfiber loop mirror 3, and slowly oscillates and attenuates (that is, rings down). Every time the intracavity light pulse is reflected back and forth, a small part of intracavity photons are transmitted out of the cavity through thesecond port 312 of thefiber coupler 31 of the second fiberoptic loop mirror 3 and detected by thephotodetector 5 . The output electrical signal of thephotodetector 5 enters the signal acquisition andprocessing system 6 . According toEquation 1, by analyzing the measured cavity ring-down time constant, high-precision measurement of intra-cavity loss can be realized.

本实施例不但具有腔镜反射率高、光谱测量范围宽和低成本的优点，而且通过输入腔镜的反射率的调制，使得入射光脉冲注入光纤谐振腔时具有高的耦合效率，注入后腔镜即恢复高的反射率，从而解决了高精细度同光耦合效率之间的矛盾，克服了在先技术的缺点，降低了光电探测器的要求，提高了测量信号的信噪比，获得更高的测量灵敏度。This embodiment not only has the advantages of high reflectivity of the cavity mirror, wide spectral measurement range and low cost, but also has high coupling efficiency when the incident light pulse is injected into the fiber resonator through the modulation of the reflectivity of the input cavity mirror, and the injection into the rear cavity The mirror restores high reflectivity, thereby solving the contradiction between high precision and optical coupling efficiency, overcoming the shortcomings of the prior technology, reducing the requirements for photodetectors, improving the signal-to-noise ratio of the measurement signal, and obtaining more High measurement sensitivity.

本发明实施例三Embodiment three of the present invention

图3为本发明实施例三：采用半导体光放大器构成的非线性光纤环形镜实现高反射和高透过特性高速切换的光纤腔衰荡传感装置示意图；Fig. 3 is the third embodiment of the present invention: a schematic diagram of an optical fiber cavity ring-down sensing device for high-speed switching between high reflection and high transmission characteristics using a nonlinear optical fiber loop mirror composed of a semiconductor optical amplifier;

图中：74为一个半导体光放大器，741为它的第二驱动电源。半导体光放大器74不仅具有光放大的作用，而且在不同入射光强的情况下，由于光学非线性效应而改变有效折射率。742为一个控制用激光器。它发出的脉冲激光信号经过第三光纤耦合器743注第三入光纤环路72。744为控制用激光器742脉冲运转的第三驱动电源，其脉冲频率和相位与信号光源1同步并可调。Among the figure: 74 is a semiconductor optical amplifier, and 741 is its second driving power supply. The semiconductoroptical amplifier 74 not only has the function of light amplification, but also changes the effective refractive index due to optical nonlinear effects under different incident light intensities. 742 is a control laser. The pulsed laser signal it sends is injected into thethird fiber loop 72 through the third fiber coupler 743. 744 is the third driving power for controlling the pulse operation of the laser 742, and its pulse frequency and phase are synchronized with thesignal light source 1 and can be adjusted.

本实施例的工作原理如下：半导体光放大器74在一定的工作电流下具有相应的增益，补偿第三光纤环路72的损耗，使光纤环形镜第一端口711和第二端口712来看起到一个高反射镜的作用。当从激光器742发出的控制光脉冲通过第三光纤耦合器743注入到第三光纤环路72时，控制光脉冲和光源1发出的测试光脉冲在半导体光放大器74上将发生非线性相互作用。该半导体光放大器74的安装位置偏离第三光纤环路72的中点，因此从第三光纤耦合器71的第三端口713和第四端口714出射的测试光脉冲将在不同时刻到达半导体光放大器74。调节第三驱动电源744的脉冲延迟时间，使控制激光器742发出的控制光脉冲到达半导体光放大器74的时刻只同顺时针和逆时针传输的测试光脉冲中的一个光脉冲同步到达半导体光放大器74并与之发生非线性相互作用。这样顺时针和逆时针传输的测试光脉冲通过第三光纤环路72时经历的相位变化就不相同。在此情况下，可控光纤环形镜7对于从光源1入射的光脉冲就起一个高透过率的作用，使光脉冲高效地进入光纤4。然后立即切断控制光脉冲，可控光纤环形镜7恢复到高反射率的状态，构建一个高精细度的振荡腔。由于半导体光放大器74的非线性响应时间极短，大致在小于纳秒量级，因此可以实现高速的切换，满足高灵敏度、高精度的腔衰荡测量。The working principle of this embodiment is as follows: the semiconductoroptical amplifier 74 has a corresponding gain under a certain operating current, and compensates the loss of the thirdoptical fiber loop 72, so that thefirst port 711 and thesecond port 712 of the optical fiber loop mirror can be viewed as The role of a highly reflective mirror. When the control light pulse emitted from the laser 742 is injected into the thirdoptical fiber loop 72 through the third fiber coupler 743 , the control light pulse and the test light pulse emitted by thelight source 1 will interact nonlinearly on the semiconductoroptical amplifier 74 . The installation position of this semiconductoroptical amplifier 74 deviates from the midpoint of the thirdoptical fiber loop 72, so the test light pulses emitted from thethird port 713 and thefourth port 714 of the thirdoptical fiber coupler 71 will arrive at the semiconductor optical amplifier atdifferent times 74. Adjust the pulse delay time of the third drive power supply 744, so that the moment when the control light pulse sent by the control laser 742 reaches the semiconductoroptical amplifier 74 only arrives at the semiconductoroptical amplifier 74 synchronously with one of the test light pulses transmitted clockwise and counterclockwise. and interact with it nonlinearly. In this way, the phase changes experienced by the test light pulses transmitted clockwise and counterclockwise when passing through the thirdoptical fiber loop 72 are different. In this case, the controllablefiber loop mirror 7 has a high transmittance for the light pulse incident from thelight source 1 , so that the light pulse enters theoptical fiber 4 efficiently. Then the control light pulse is cut off immediately, and the controllable fiberoptic loop mirror 7 returns to a state of high reflectivity, and a high-precision oscillation cavity is constructed. Since the nonlinear response time of the semiconductoroptical amplifier 74 is extremely short, approximately less than nanoseconds, high-speed switching can be realized to meet the high-sensitivity and high-precision cavity ring-down measurement.

本发明实施例四Embodiment 4 of the present invention

图4为本发明实施例四：采用高非线性光纤构成的非线性光纤环形镜实现高反射和高透过特性高速切换光纤腔衰荡传感装置示意图；图中754为一段高非线性光纤，与光纤环路72直接相连接。751是一个产生起控制作用的超短脉冲激光器，它在脉冲发生器752的驱动下工作。脉冲发生器752与第一驱动器11同步，并具有可调的时延特性。超短脉冲激光器751发出的激光通过第四光纤耦合器753注入高非线性光纤754。Fig. 4 is a schematic diagram ofEmbodiment 4 of the present invention: using a nonlinear optical fiber loop mirror composed of a highly nonlinear optical fiber to realize high reflection and high transmission characteristics and high-speed switching optical fiber cavity ring-down sensing device; 754 in the figure is a section of highly nonlinear optical fiber, It is directly connected to thefiber optic loop 72. 751 is an ultra-short pulse laser that generates a control function, and it works under the drive of apulse generator 752 . Thepulse generator 752 is synchronized with thefirst driver 11 and has adjustable delay characteristics. The laser light emitted by theultrashort pulse laser 751 is injected into the highnonlinear fiber 754 through thefourth fiber coupler 753 .

该结构的工作原理如下：高非线性光纤具有比常规光纤高得多的光学非线性效应。当测试光脉冲从激光光源1发出经过第三光纤耦合器71分束，分别以顺时针和逆时针方向通过第三光纤环路72；控制激光脉冲与测试脉冲同步发出，控制延时使其与顺时针光波同时到达高非线性光纤段754；而逆时针光波在控制光波到达非线性光纤段754之前已经通过该光纤段。逆时针光波没有受到高非线性光纤754的作用，而顺指针光波经受了非线性效应的交叉相位调制效应，获得了有较大差别的相位变化。这样，这二束光波回到第三光纤耦合器71时，不会由于干涉而全部从入射端口711反射回去，而是以较高的透过率注入光纤4。在这一脉冲通过光纤环形镜开关7之后，控制激光器751处于脉冲间隔期。此时，高非线性光纤段754对于顺时针和逆时针光波没有区别，产生相同的相移。当它们回到第三光纤耦合器71时，将由于干涉而向入射端口反射，对于从其第一端口711和第二端口712入射的光波都起到一个高反射镜的作用。从而达到高效率注入高Q值衰荡腔的目的。The working principle of this structure is as follows: High nonlinear fiber has a much higher optical nonlinear effect than conventional fiber. When the test light pulse is sent from thelaser light source 1 and passed through the thirdoptical fiber coupler 71 to split the beam, it passes through the thirdoptical fiber loop 72 in a clockwise and counterclockwise direction respectively; the control laser pulse is sent out synchronously with the test pulse, and the delay is controlled to make it coincide with the test pulse. The clockwise light waves reach the highlynonlinear fiber segment 754 at the same time; while the counterclockwise light waves have passed through thefiber segment 754 before the control light waves reach thenonlinear fiber segment 754 . The counterclockwise light wave is not affected by the highly nonlinearoptical fiber 754, while the clockwise light wave is subjected to the cross-phase modulation effect of the nonlinear effect, and a phase change with a large difference is obtained. In this way, when the two light waves return to thethird fiber coupler 71 , they will not be completely reflected back from theincident port 711 due to interference, but will be injected into theoptical fiber 4 with a higher transmittance. After this pulse passes through the fiber opticloop mirror switch 7, thecontrol laser 751 is in the pulse interval. At this point, the highlynonlinear fiber segment 754 makes no difference between clockwise and counterclockwise light waves, producing the same phase shift. When they return to the thirdoptical fiber coupler 71, they will reflect to the incident port due to interference, and act as a high reflection mirror for the light waves incident from thefirst port 711 and thesecond port 712 thereof. So as to achieve the purpose of injecting high-Q ring-down cavity with high efficiency.

本发明实施例五Embodiment five of the present invention

图5本发明实施例五：采用光纤放大器构成的非线性光纤环形镜实现高反射和高透过特性高速切换的光纤腔衰荡传感装置示意图。图中764为一段稀土掺杂有源光纤；它与第三光纤环路72相连接。761为向有源光纤提供激励能量的泵浦激光器。泵浦激光器在第二驱动器762推动下工作。第二驱动器762与测试光源的第一驱动器11同步，并具有可调的时延特性。泵浦激光脉冲通过波分复用器763注入有源光纤764，使其具有光放大的作用。Fig. 5Embodiment 5 of the present invention: a schematic diagram of an optical fiber cavity ring-down sensing device that uses a nonlinear optical fiber loop mirror composed of an optical fiber amplifier to realize high-speed switching between high reflection and high transmission characteristics. 764 in the figure is a section of rare earth doped active optical fiber; it is connected with the thirdoptical fiber loop 72 . 761 is a pump laser that provides excitation energy to the active fiber. The pump laser is driven by thesecond driver 762 to work. Thesecond driver 762 is synchronized with thefirst driver 11 of the test light source, and has adjustable delay characteristics. The pump laser pulse is injected into the activeoptical fiber 764 through thewavelength division multiplexer 763, so that it has the effect of optical amplification.

该结构的工作原理如下：稀土掺杂有源光纤764在泵浦激光的作用下，吸收泵浦激光光子能量，获得粒子数的反转；它对于同时注入的信号光具有放大作用。当测试光脉冲从激光光源1发出经过第三光纤耦合器71分束，分别以顺时针和逆时针方向通过第三光纤环路72；泵浦激光脉冲从泵浦激光器761与测试脉冲同步发出，经过波分复用器763注入有源光纤764；控制延时使其与顺时针光波同时到达有源光纤段764，从而使顺时针光波获得放大。而逆时针光波在泵浦光脉冲到达有源光纤段764之前已经通过该光纤段。逆时针光波没有受到有源光纤764的放大作用。这样，这二束光波回到第三光纤耦合器71时，由于两束光波的强度不同，干涉的结果是一部分光从入射端口711反射回去，另外一一部分光波向端口712输出进入光纤4。在这一脉冲通过光纤环形镜开关7之后，泵浦激光器761处于脉冲间隔期，但是维持一个低功率水平的直流输出，使有源光纤764维持不损耗零增益的状态。这样，它对于顺时针和逆时针光波没有区别，既无吸收，也无增益，并经历相同的相移。当它们回到第三光纤耦合器71时，将由于干涉而向入射端口反射，对于从其第一端口711和和第二端口712入射的光波都起到一个高反射镜的作用。从而达到高效率注入高Q值衰荡腔的目的。The working principle of this structure is as follows: under the action of the pump laser, the rare earth dopedactive fiber 764 absorbs the photon energy of the pump laser to obtain the inversion of the number of particles; it has the effect of amplifying the signal light injected at the same time. When the test light pulse is sent from thelaser light source 1 and split by thethird fiber coupler 71, it passes through thethird fiber loop 72 clockwise and counterclockwise respectively; the pump laser pulse is sent out synchronously with the test pulse from thepump laser 761, Inject theactive fiber 764 through thewavelength division multiplexer 763; control the delay to make it reach theactive fiber segment 764 at the same time as the clockwise light wave, so that the clockwise light wave is amplified. On the other hand, the counterclockwise light wave has already passed through theactive fiber segment 764 before the pump light pulse reaches this fiber segment. The counterclockwise light wave is not amplified by the activeoptical fiber 764 . Like this, when these two beams of light waves return to thethird fiber coupler 71, because the intensity of the two beams of light waves is different, the result of the interference is that a part of the light waves is reflected back from theincident port 711, and another part of the light waves is output to theport 712 and enters theoptical fiber 4. After this pulse passes through the fiberloop mirror switch 7, thepump laser 761 is in the pulse interval, but maintains a DC output at a low power level, so that theactive fiber 764 maintains a zero-gain state without loss. As such, it makes no difference between clockwise and counterclockwise light waves, neither absorbs nor gains, and experiences the same phase shift. When they return to thethird fiber coupler 71, they will reflect to the incident port due to interference, and act as a high reflection mirror for the incident light waves from thefirst port 711 and thesecond port 712 thereof. So as to achieve the purpose of injecting high-Q ring-down cavity with high efficiency.

本发明的全光纤腔衰荡吸收光谱检测传感装置可以实现对腔内损耗的高精度测量，可以用来进行多种参量的传感测量，只要被测参量能够引起光纤谐振腔的损耗改变，或者被测参量的变化能够通过转换机构转换为光纤谐振腔的损耗改变，例如弯曲、应变、压力、气体/液体的浓度/折射率等，都能够用本发明的全光纤腔衰荡吸收光谱检测传感装置进行测量。The all-fiber cavity ring-down absorption spectrum detection sensing device of the present invention can realize high-precision measurement of intracavity loss, and can be used for sensing and measuring various parameters, as long as the measured parameters can cause the loss of the optical fiber resonant cavity to change, Or the change of the measured parameter can be converted into the loss change of the optical fiber resonator through the conversion mechanism, such as bending, strain, pressure, gas/liquid concentration/refractive index, etc., can be detected by the all-fiber cavity ring-down absorption spectrum of the present invention Sensing device to measure.

Claims (5)

Translated fromChinese

1.一种全光纤腔衰荡吸收光谱检测传感装置，依次由光源(1)及其第一驱动器(11)、光纤谐振腔、光电探测器(5)和信号采集处理系统(6)连接而构成，其特征在于所述的光纤谐振腔由第一光纤环形镜(2)通过光纤(4)与第二光纤环形镜(3)相连构成；所述的第一光纤环形镜(2)山第一光纤耦合器(21)同侧的第三端口(213)和第四端口(214)同第一光纤环路(22)连接构成；所述的第二光纤环形镜(3)由第二光纤耦合器(31)同侧的第三端口(313)和第四端口(314)同第二光纤环路(32)连接构成；所述的光源(1)的输出端与第一光纤耦合器(21)的第一端口(211)相连，第一光纤耦合器(21)的第二端口(212)与光纤(4)的一端相连；该光纤(4)另一端连接第二光纤耦合器(31)的第一端口(311)，该第二光纤耦合器(31)的第二端口(312)经光电探测器(5)和信号采集处理系统(6)相连。1. An all-fiber cavity ring-down absorption spectrum detection and sensing device, which is sequentially connected by a light source (1) and its first driver (11), an optical fiber resonant cavity, a photodetector (5) and a signal acquisition and processing system (6) And constitute, it is characterized in that described optical fiber resonant cavity is connected to form by first optical fiber loop mirror (2) by optical fiber (4) and second optical fiber loop mirror (3); Described first optical fiber loop mirror (2) mountain The third port (213) and the fourth port (214) of the same side of the first optical fiber coupler (21) are connected with the first optical fiber loop (22) to form; the second optical fiber loop mirror (3) is formed by the second The third port (313) and the fourth port (314) on the same side of the fiber coupler (31) are connected with the second fiber loop (32) to form; the output end of the light source (1) is connected to the first fiber coupler The first port (211) of (21) links to each other, and the second port (212) of the first optical fiber coupler (21) links to each other with an end of the optical fiber (4); This optical fiber (4) other end connects the second optical fiber coupler ( 31), the second port (312) of the second optical fiber coupler (31) is connected to the signal acquisition and processing system (6) via the photodetector (5).2.一种全光纤腔衰荡吸收光谱检测传感装置，依次由光源(1)及其第一驱动器(11)、光纤谐振腔、光电探测器(5)和信号采集处理系统(6)连接而构成，其特征在于所述的光纤谐振腔由一光纤环形镜开关(7)通过光纤(4)与第二光纤环形镜(3)相连构成；所述的第二光纤环形镜(3)由第二光纤耦合器(31)同侧的第三端口(313)和第四端口(314)同第二光纤环路(32)连接构成；所述的光源(1)的输出端与该光纤环形镜开关(7)的第一端口(711)相连；该光纤环形镜开关(7)的第二端口(712)与所述的光纤(4)的一端相连；该光纤(4)另一端连接第二光纤耦合器(31)的第一端口(311)，该第二光纤耦合器(31)的第二端口(312)经光电探测器(5)和信号采集处理系统(6)相连，所述的光纤环形镜开关(7)的构成是：由第三光纤耦合器(71)同侧的第三端口(713)和第四端口(714)与第三光纤环路(72)的两端连接，在第三光纤环路(72)偏离中心位置接入光调制单元(73)，该光调制单元(73)设有第一驱动电源(74)，该第一驱动电源(74)与所述的第一驱动器(11)相连并同步运转。2. An all-fiber cavity ring-down absorption spectrum detection and sensing device, which is sequentially connected by a light source (1) and its first driver (11), an optical fiber resonant cavity, a photodetector (5) and a signal acquisition and processing system (6) And constitute, it is characterized in that described optical fiber resonant cavity is connected to form by a fiber optic loop mirror switch (7) by optical fiber (4) and the second fiber optic loop mirror (3); Described second fiber optic loop mirror (3) is formed by The third port (313) and the fourth port (314) of the same side of the second optical fiber coupler (31) are connected with the second optical fiber loop (32) to form; the output end of the light source (1) is connected to the optical fiber loop The first port (711) of the mirror switch (7) is connected; the second port (712) of the optical fiber ring mirror switch (7) is connected with one end of the optical fiber (4); the other end of the optical fiber (4) is connected to the first The first port (311) of the two optical fiber couplers (31), the second port (312) of the second optical fiber coupler (31) is connected with the signal acquisition and processing system (6) through the photodetector (5), the described The composition of the optical fiber loop mirror switch (7) is: the third port (713) and the fourth port (714) on the same side of the third optical fiber coupler (71) are connected to the two ends of the third optical fiber loop (72) , the optical modulation unit (73) is connected to the off-center position of the third optical fiber loop (72), the optical modulation unit (73) is provided with a first driving power supply (74), and the first driving power supply (74) is connected to the The first driver (11) is connected and runs synchronously.3.一种全光纤腔衰荡吸收光谱检测传感装置，依次由光源(1)及其第一驱动器(11)、光纤谐振腔、光电探测器(5)和信号采集处理系统(6)连接而构成，其特征在于所述的光纤谐振腔由一光纤环形镜开关(7)通过光纤(4)与第二光纤环形镜(3)相连构成；所述的第二光纤环形镜(3)由第二光纤耦合器(31)同侧的第三端口(313)和第四端口(314)同第二光纤环路(32)连接构成；所述的光源(1)的输出端与该光纤环形镜开关(7)的第一端口(711)相连；该光纤环形镜开关(7)的第二端口(712)与所述的光纤(4)的一端相连；该光纤(4)另一端连接第二光纤耦合器(31)的第一端口(311)，该第二光纤耦合器(31)的第二端口(312)经光电探测器(5)和信号采集处理系统(6)相连，所述的光纤环形镜开关(7)的构成是：由第三光纤耦合器(71)同侧的第三端口(713)和第四端口(714)与第三光纤环路(72)的两端连接，在第三光纤环路(72)偏离中心位置接入一个半导体光放大器(74)和第四光纤耦合器(743)，所述的半导体光放大器(74)具有第二驱动电源(741)，所述的第四光纤耦合器(743)的第三端口连接一控制激光器(742)，该控制激光器(742)连接第三驱动电源(744)，所述的第三驱动电源(744)与所述的第一驱动器(11)连接并同步工作。3. An all-fiber cavity ring-down absorption spectrum detection and sensing device, which is sequentially connected by a light source (1) and its first driver (11), an optical fiber resonant cavity, a photodetector (5) and a signal acquisition and processing system (6) And constitute, it is characterized in that described optical fiber resonant cavity is connected to form by a fiber optic loop mirror switch (7) by optical fiber (4) and the second fiber optic loop mirror (3); Described second fiber optic loop mirror (3) is formed by The third port (313) and the fourth port (314) of the same side of the second optical fiber coupler (31) are connected with the second optical fiber loop (32) to form; the output end of the light source (1) is connected to the optical fiber loop The first port (711) of the mirror switch (7) is connected; the second port (712) of the optical fiber ring mirror switch (7) is connected with one end of the optical fiber (4); the other end of the optical fiber (4) is connected to the first The first port (311) of the two optical fiber couplers (31), the second port (312) of the second optical fiber coupler (31) is connected with the signal acquisition and processing system (6) through the photodetector (5), the described The composition of the optical fiber loop mirror switch (7) is: the third port (713) and the fourth port (714) on the same side of the third optical fiber coupler (71) are connected to the two ends of the third optical fiber loop (72) , inserting a semiconductor optical amplifier (74) and a fourth optical fiber coupler (743) at the off-center position of the third optical fiber loop (72), the described semiconductor optical amplifier (74) has a second driving power supply (741), The third port of the fourth optical fiber coupler (743) is connected to a control laser (742), and the control laser (742) is connected to a third driving power supply (744), and the third driving power supply (744) is connected to the The above-mentioned first driver (11) is connected and works synchronously.4.一种全光纤腔衰荡吸收光谱检测传感装置，依次由光源(1)及其第一驱动器(11)、光纤谐振腔、光电探测器(5)和信号采集处理系统(6)连接而构成，其特征在于所述的光纤谐振腔由一光纤环形镜开关(7)通过光纤(4)与第二光纤环形镜(3)相连构成；所述的第二光纤环形镜(3)由第二光纤耦合器(31)同侧的第三端口(313)和第四端口(314)同第二光纤环路(32)连接构成；所述的光源(1)的输出端与该光纤环形镜开关(7)的第一端口(711)相连；该光纤环形镜开关(7)的第二端口(712)与所述的光纤(4)的一端相连；该光纤(4)另一端连接第二光纤耦合器(31)的第一端口(311)，该第二光纤耦合器(31)的第二端口(312)经光电探测器(5)和信号采集处理系统(6)相连，所述的光纤环形镜开关(7)的构成是：由第三光纤耦合器(71)同侧的第三端口(713)和第四端口(714)与第三光纤环路(72)的两端连接，在第三光纤环路(72)中偏离中心位置接入一段高非线性光纤(754)和第四光纤耦合器(753)，该第四光纤耦合器(753)连接一超短脉冲激光器(751)，该超短脉冲激光器(751)在脉冲发生器(752)的驱动下工作，该脉冲发生器(752)与第一驱动器(11)相连并同步工作。4. An all-fiber cavity ring-down absorption spectrum detection and sensing device, which is sequentially connected by a light source (1) and its first driver (11), an optical fiber resonant cavity, a photodetector (5) and a signal acquisition and processing system (6) And constitute, it is characterized in that described optical fiber resonant cavity is connected to form by a fiber optic loop mirror switch (7) by optical fiber (4) and the second fiber optic loop mirror (3); Described second fiber optic loop mirror (3) is formed by The third port (313) and the fourth port (314) of the same side of the second optical fiber coupler (31) are connected with the second optical fiber loop (32) to form; the output end of the light source (1) is connected to the optical fiber loop The first port (711) of the mirror switch (7) is connected; the second port (712) of the optical fiber ring mirror switch (7) is connected with one end of the optical fiber (4); the other end of the optical fiber (4) is connected to the first The first port (311) of the two optical fiber couplers (31), the second port (312) of the second optical fiber coupler (31) is connected with the signal acquisition and processing system (6) through the photodetector (5), the described The composition of the optical fiber loop mirror switch (7) is: the third port (713) and the fourth port (714) on the same side of the third optical fiber coupler (71) are connected to the two ends of the third optical fiber loop (72) , in the third optical fiber loop (72), a section of high nonlinear optical fiber (754) and a fourth optical fiber coupler (753) are connected to an off-center position, and the fourth optical fiber coupler (753) is connected to an ultrashort pulse laser ( 751), the ultrashort pulse laser (751) works under the drive of the pulse generator (752), and the pulse generator (752) is connected with the first driver (11) and works synchronously.5.一种全光纤腔衰荡吸收光谱检测传感装置，依次由光源(1)及其第一驱动器(11)、光纤谐振腔、光电探测器(5)和信号采集处理系统(6)连接而构成，其特征在于所述的光纤谐振腔由一光纤环形镜开关(7)通过光纤(4)与第二光纤环形镜(3)相连构成；所述的第二光纤环形镜(3)由第二光纤耦合器(31)同侧的第三端口(313)和第四端口(314)同第二光纤环路(32)连接构成；所述的光源(1)的输出端与该光纤环形镜开关(7)的第一端口(711)相连；该光纤环形镜开关(7)的第二端口(712)与所述的光纤(4)的一端相连；该光纤(4)另一端连接第二光纤耦合器(31)的第一端口(311)，该第二光纤耦合器(31)的第二端口(312)经光电探测器(5)和信号采集处理系统(6)相连，所述的光纤环形镜开关(7)的构成是：由第三光纤耦合器(71)同侧的第三端口(713)和第四端口(714)与第三光纤环路(72)的两端连接，在第三光纤环路(72)中偏离中心位置接入一波分复用器(763)和一段有源光纤(764)，所述的波分复用器(763)的第三端连接一泵浦激光器(761)，该泵浦激光器(761)设有第二驱动器(762)，所述的第二驱动器(762)与第一驱动器(11)相连并同步工作。5. An all-fiber cavity ring-down absorption spectrum detection and sensing device, which is sequentially connected by a light source (1) and its first driver (11), an optical fiber resonant cavity, a photodetector (5) and a signal acquisition and processing system (6) And constitute, it is characterized in that described optical fiber resonant cavity is connected to form by a fiber optic loop mirror switch (7) by optical fiber (4) and the second fiber optic loop mirror (3); Described second fiber optic loop mirror (3) is formed by The third port (313) and the fourth port (314) of the same side of the second optical fiber coupler (31) are connected with the second optical fiber loop (32) to form; the output end of the light source (1) is connected to the optical fiber loop The first port (711) of the mirror switch (7) is connected; the second port (712) of the optical fiber ring mirror switch (7) is connected with one end of the optical fiber (4); the other end of the optical fiber (4) is connected to the first The first port (311) of the two optical fiber couplers (31), the second port (312) of the second optical fiber coupler (31) is connected with the signal acquisition and processing system (6) through the photodetector (5), the described The composition of the optical fiber loop mirror switch (7) is: the third port (713) and the fourth port (714) on the same side of the third optical fiber coupler (71) are connected to the two ends of the third optical fiber loop (72) , access a wavelength division multiplexer (763) and a section of active optical fiber (764) off-center in the third optical fiber loop (72), the third end of the wavelength division multiplexer (763) is connected A pumping laser (761), the pumping laser (761) is provided with a second driver (762), and the second driver (762) is connected with the first driver (11) and works synchronously.

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