WO2017113965A1 - 一种高分辨率偏振低相干干涉压力测量装置及方法 - Google Patents

一种高分辨率偏振低相干干涉压力测量装置及方法 Download PDF

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WO2017113965A1
WO2017113965A1 PCT/CN2016/103524 CN2016103524W WO2017113965A1 WO 2017113965 A1 WO2017113965 A1 WO 2017113965A1 CN 2016103524 W CN2016103524 W CN 2016103524W WO 2017113965 A1 WO2017113965 A1 WO 2017113965A1
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wedge
spatial
polarizer
birefringent
light
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王双
刘铁根
江俊峰
肖梦楠
刘琨
何盼
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Tianjin University
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
    • G01L9/0026—Transmitting or indicating the displacement of flexible, deformable tubes by electric, electromechanical, magnetic or electromagnetic means
    • G01L9/0032—Transmitting or indicating the displacement of flexible, deformable tubes by electric, electromechanical, magnetic or electromagnetic means using photoelectric means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L11/00—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00
    • G01L11/02—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00 by optical means

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  • the invention belongs to the field of optical fiber sensing, and in particular relates to a high-resolution polarization low-coherence interference pressure measuring device and method based on an area array camera.
  • the electronic scanning type polarization low-coherence interference system utilizes a birefringent crystal to spatially generate an optical path difference.
  • a low-coherence interference system has no moving parts and has the advantages of compact structure and strong stability.
  • the existing electronic scanning polarization low-coherence interference demodulation system uses a linear array photodetector array (such as a linear array CCD) to acquire low-coherence interference fringes, and the demodulation method is also generally based on one-dimensional low-coherence interference fringe expansion research.
  • the measurement range and measurement resolution are limited by the size and number of detector pixels. It is usually necessary to balance the two important indicators of measurement range and measurement resolution. It is difficult to achieve two important indicators of large-scale and high-resolution at the same time, so that the application range of the polarization-type low-coherence interference demodulation system is limited.
  • the present invention proposes a high-resolution polarization low-coherence interference pressure measuring device and method for acquiring a two-dimensional low-coherence interference fringe signal based on a two-dimensional electronic scanning demodulation interferometer, using a belt
  • the optical leverage effect of the spatially divergent birefringent wedge achieves a fiber optic pressure sensing demodulation method with both large measurement range and high resolution.
  • the invention provides a high-resolution polarization low-coherence interference pressure measuring device. From the input end to the output end, the device sequentially sets a broadband light source 1, a fiber coupler 2, a fiber optic sensor 3, a collimating lens 4, and a polarizing 5, a birefringent wedge 6 with a spatial tilt angle, an analyzer 7, an area array camera 8 and a signal processing unit 9, wherein: the fiber coupler 2 introduces light emitted from the broadband light source 1 into the fiber Fabry sensor 3, and Introducing the light returned by the fiber Fabry-Perot sensor 3 into the interferometric demodulation optical path; the fiber Fabry-Perot sensor 3 converts the pressure change into a Faber cavity length change, and the different pressures correspond to different Faber cavities; the collimating lens 4 a polarizer 5, a birefringent wedge 6 with a spatial tilt angle, an analyzer 7 and an area array camera 8 constitute an interference demodulator; the collimator lens 4 is disposed at the forefront of the
  • the low coherence interference fringes are scaled in different degrees in the horizontal and vertical directions, in one direction.
  • the interference fringes are compressed to achieve an expansion of the measurement range; the local interference fringes are broadened in the other direction to achieve an increase in measurement resolution; and the analyzer 7 pairs the birefringent wedges 6 with a spatial tilt angle
  • the mutually orthogonal linearly polarized lights are projected in the same direction and interfered; the interference fringes generated after passing through the analyzer are acquired by the area array camera 8; the interference fringes collected by the area array camera are processed by the signal processing unit 9 Finally, the pressure measurement results are obtained.
  • the invention also proposes a pressure measuring method for a high-resolution polarization low-coherence interference system, which comprises the following steps:
  • Step 1 The light emitted by the broadband light source passes through the fiber coupler to reach the fiber Fabry sensor;
  • Step 2 The optical signal modulated by the fiber optic sensor is derived from the outlet of the coupler, collimated by the collimating lens, polarized by the polarizer, and then incident on the birefringent wedge with spatial inclination
  • the polarizing axis direction of the polarizer is placed at 45 degrees with the optical axis direction of the birefringent wedge with spatial inclination, and the birefringent wedge with a spatial inclination
  • the polarized light is decomposed into two linearly polarized lights, o and e, which are orthogonal to each other, and the two components produce an optical path difference in a birefringent wedge with a spatial tilt angle.
  • x is the lateral distance from the incident spot to the apex of the wedge
  • y is the longitudinal distance from the incident spot to the apex of the wedge
  • n o and n e are the o-index and the e-index, respectively, of the birefringent crystal
  • d (x, y) is the wedge thickness at the incident spot
  • d 0 is the wedge thickness at the fixed point of the wedge
  • the interference fringes are compressed by designing a large wedge angle to expand the measurement range, and in the other direction, the local interference fringes are widened by designing a small wedge angle to improve the measurement resolution;
  • Step 3 The analyzer is placed at 45 degrees with the optical axis of the birefringent wedge with a spatial inclination, and the two mutually perpendicular o and e rays transmitted through the birefringent wedge with a spatial inclination are re-applied.
  • Step 4 The signal processing unit processes the two-dimensional interference fringe signal output by the area array camera, and obtains a preliminary peak position by the low coherence interference signal in the direction of the large wedge angle, based on the coordinates of the preliminary peak position, passing through the micro wedge angle direction.
  • the low coherent interference signal obtains accurate peak position of the fringe, and finally extracts the Fabry cavity length information, and obtains corresponding pressure measurement results to achieve high-resolution pressure demodulation.
  • the invention effectively utilizes the birefringence effect to form an optical lever, and realizes different degrees of scaling of the low coherence interference fringes in the horizontal and vertical directions by designing the two-dimensional spatial wedge angle of the birefringent wedge with spatial inclination;
  • the spatial wedge angle of the birefringent wedge in the vertical direction is introduced, and the image receiving is performed by the area array camera, which can realize pressure demodulation that simultaneously satisfies a large measurement range and high resolution.
  • FIG. 1 is a schematic structural view of a high-resolution polarization low-coherence interference pressure measuring device based on an area array camera;
  • FIG. 2 is a schematic view showing the structure of a birefringent wedge with a spatial inclination
  • 3 is a single-frame experimental result image at four pressure points of 11 kPa, 55 kPa, 101 kPa, and 255 kPa received by the area array camera;
  • Figure 4 is the original data of the 1020th row and the 1044th column of a certain frame image under the pressure of 101kPa;
  • Figure 5 is the fluctuation of the results of the data processing of the 10th and 20th lines of the 150-frame image at 101 kPa;
  • Reference numerals 1. Broadband light source 2, fiber coupler 3, fiber Faber sensor 4, collimator lens 5, polarizer 6, birefringent wedge 7 with spatial inclination, analyzer 8; area array camera 9 , signal processing unit.
  • Embodiment 1 A high resolution polarization low coherence interference pressure measuring device based on area array camera
  • the demodulation interferometer is composed of a polarizer 5, a birefringent wedge 6 with a spatial tilt angle, and an analyzer 7 due to the birefringence effect of the birefringent wedge 6 with a spatial tilt angle.
  • the signal forms a spatial low-coherence interference fringe through the birefringent wedge 6 with a spatial tilt angle and is received by the area array camera 8, and the signal processing unit 9 processes the interference fringe signal output from the area array camera 8 as a birefringent wedge with a spatial tilt angle
  • the optical path difference caused by 6 matches the optical path difference caused by the fiber Fabry sensor 3
  • significant low-coherence interference fringes are generated in the corresponding partial regions of the area array camera 8.
  • the broadband light source 1 uses a SLED light source module with a center wavelength of 750 nm
  • the fiber coupler 2 uses a 2 ⁇ 2 multimode coupler
  • the polarizer 5 and the analyzer 7 adopt a Glan Thomson prism with space.
  • the dihedral wedge 6 of the dip angle uses a lithium niobate wedge
  • the area array CCD is used as the area array camera 8.
  • the pixel size is 3.45 ⁇ m*3.45 ⁇ m, and the number of pixels is 2456*2058.
  • Embodiment 2 A high resolution polarization low coherence interference pressure measurement method based on area array camera
  • the pressure measurement method of the above-mentioned high resolution polarization low coherence interference device based on area array camera is as follows:
  • Step 1 The light emitted by the broadband light source 1 passes through the fiber coupler 2 to reach the fiber Fabry sensor 3, and the fiber Faber sensor 3 is used to sense the external atmospheric pressure, and the two reflecting surfaces of the Faber cavity constitute a sensing interferometer.
  • the distance between the two reflecting surfaces of the chamber is linear with atmospheric pressure;
  • Step 2 The optical signal modulated by the fiber optic sensor 3 is derived from the exit of the fiber coupler 2, collimated by the collimating lens 4, and then polarized by the polarizer 5, and then incident into the space.
  • the diverging wedge 6 of the dip angle, the polarization axis direction of the polarizer 5 is placed at 45 degrees with the optical axis direction of the birefringent wedge 6 having a spatial inclination angle, and the polarized light is polarized in the birefringent wedge 6 with a spatial inclination angle Decomposed into two linearly polarized lights (o light and e light) that are orthogonal to each other.
  • ⁇ and The inclination of the wedge in the horizontal and vertical directions d 0 is the wedge thickness at the fixed point of the wedge, and the optical leverage effect of the birefringent wedge 6 with spatial inclination is used to achieve low coherence interference fringes in horizontal and vertical directions.
  • Step 3 The analyzer 7 placed at 45 degrees with the optical axis direction of the birefringent wedge 6 having a spatial inclination angle transmits the two mutually perpendicular o lights and e transmitted through the birefringent wedge 6 with the spatial inclination angle.
  • the light is superimposed on the detection direction to generate interference fringes, and is received by the area array camera 8;
  • Step 4 The signal processing unit 9 processes the two-dimensional interference fringe signal output by the area array camera 8, first extracting the line data in the direction of the large wedge angle, that is, in the horizontal direction, and obtaining the preliminary result by processing the low-coherence interference signal in the direction of the large wedge angle.
  • Peak position based on the coordinates of the initial peak position, extracts the number of columns in the direction of the small wedge angle, ie, the vertical direction According to the low coherence interference signal in the direction of the small wedge angle, the accurate peak position of the fringe is obtained, and finally the Fabry cavity length information is extracted, and the corresponding pressure measurement result is obtained to realize high-resolution pressure demodulation.
  • FIG. 3 shows the image of the single-frame experiment at four pressure points of 11 kPa, 55 kPa, 101 kPa, and 255 kPa. It can be seen that the position of the central stripe changes with the pressure in one direction.
  • the vertical direction analysis is performed, and the signal of the 1044th column is selected (the original signal is as shown in Fig. 4(b)), and the maximum value of the central stripe is obtained by calculation.
  • the location is at the 1077th pixel of the column;
  • the 1020th line signal is taken for data processing.
  • the result is shown in Fig. 5.
  • the position of the central stripe maximum is in the range of 1043 ⁇ 1046 pixels, corresponding to the Faber cavity.
  • the long variation is 0.03 ⁇ m, which can initially locate the peak position of the stripe;
  • the data of the 1044th column is taken for data processing.
  • the obtained result is shown in Fig. 6.
  • the position of the maximum value of the central stripe is in the range of 1077 to 1079 pixels in the column, and the corresponding Faber cavity
  • the long change amount is 0.005 ⁇ m, and the measured cavity length value fluctuates less, which can improve the demodulation resolution.
  • the broadband light source may be an LED light source or an SLD light source
  • the birefringent crystal may be a lithium niobate crystal, a magnesium fluoride crystal, an ice crystal, a YVO4 crystal;
  • the polarizer and the analyzer may be a polarizing prism such as a Glan-Taylor prism, a Glan-Thomson prism, or a polarizer;
  • the area array camera can be an area array CMOS camera or an area array CCD camera;
  • the processing unit can be implemented by an embedded system in addition to a computer implementation
  • the fiber optic device portion described above can also be replaced with a corresponding spatial optics.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Length Measuring Devices By Optical Means (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Instruments For Measurement Of Length By Optical Means (AREA)
  • Spectrometry And Color Measurement (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

一种高分辨率偏振低相干干涉压力测量装置，从输入端到输出端，该装置依次设置宽带光源(1)、光纤耦合器(2)、光纤法珀传感器(3)、准直透镜(4)、起偏器(5)、带空间倾角的双折射光楔(6)、检偏器(7)、面阵相机(8)以及信号处理单元(9)，其中：光纤耦合器(2)将宽带光源(1)发出的光引入到光纤法珀传感器(3)，并将光纤法珀传感器(3)返回的光引入到干涉解调光路中；光纤法珀传感器(3)将压力变化转化为法珀腔腔长变化，不同压力对应不同法珀腔腔长；准直透镜(4)、起偏器(5)、带空间倾角的双折射光楔(6)、检偏器(7)、面阵相机(8)构成干涉解调器；准直透镜(4)设置在干涉解调光路最前端，对光束进行会聚准直；起偏器(5)将准直透镜准直后的输入信号光进行起偏；带空间倾角的双折射光楔(6)将起偏器(5)产生的线偏振光再产生两个正交的线偏振光，使这两束正交的线偏振光具有沿光楔厚度变化方向呈线性分布的空间光程差，通过带空间倾角的双折射光楔(6)的二维空间楔角，实现低相干干涉条纹在水平和垂直方向上不同程度的缩放。还提供了一种高分辨率偏振低相干干涉压力测量方法。

Description

一种高分辨率偏振低相干干涉压力测量装置及方法 技术领域
本发明属于光纤传感领域，特别是涉及一种基于面阵相机的高分辨率偏振低相干干涉压力测量装置及方法。
背景技术
1983年Al-Chalabi等人(S.A.Al-Chalabi,B.Culshaw，D.E.N.Davies，Partially coherent sources in interferometric sensors，First International Conference on Optical Fibre Sensors，1983:26-28)首次在光纤传感领域提出了基于低相干干涉的解调方法。基于低相干干涉技术的解调干涉仪主要分为机械扫描型和电子扫描型两类，这两种类型的干涉仪其最终目的都是在时间轴或空间轴上产生一系列的光程差，当解调干涉仪产生的某个光程差与传感器微腔产生的光程差相匹配时，会产生低相干干涉条纹峰值，通过解调计算出峰值位置，就能得到法珀腔长信息，进而得到导致法珀腔长变化的外界物理量的信息。
电子扫描型偏振低相干干涉系统利用双折射晶体在空间上产生光程差，这类低相干干涉系统没有移动部件，具有结构紧凑、稳定性强的优点。现有电子扫描型偏振型低相干干涉解调系统使用线阵光电探测器阵列(如线阵CCD)对低相干干涉条纹进行采集，解调方法也普遍基于一维低相干干涉条纹展开研究，通过光纤法珀压力传感器微腔长度进行压力参量测量时，其测量范围和测量分辨率受到探测器像元尺寸和数量的限制，通常需要在测量范围和测量分辨率这两个重要指标上进行权衡和取舍，很难同时实现大范围和高分辨这两个重要指标，使得偏振型低相干干涉解调系统应用范围受限。
发明内容
基于上述现有技术存在的问题，本发明提出了一种高分辨率偏振低相干干涉压力测量装置及方法，基于二维电子扫描型解调干涉仪获取二维低相干干涉条纹信号，利用带 空间倾角的双折射光楔的光学杠杆效应实现同时具有大测量范围和高分辨率的光纤压力传感解调方法。
本发明提出的一种高分辨率偏振低相干干涉压力测量装置，从输入端到输出端，该装置依次设置宽带光源1、光纤耦合器2、光纤法珀传感器3、准直透镜4、起偏器5、带空间倾角的双折射光楔6、检偏器7、面阵相机8以及信号处理单元9，其中：光纤耦合器2将宽带光源1发出的光引入到光纤法珀传感器3，并将光纤法珀传感器3返回的光引入到干涉解调光路中；光纤法珀传感器3将压力变化转化为法珀腔腔长变化，不同压力对应不同法珀腔腔长；所述准直透镜4、起偏器5、带空间倾角的双折射光楔6、检偏器7、面阵相机8构成干涉解调器；准直透镜4设置在干涉解调光路最前端，对光束进行会聚准直；起偏器5将准直透镜准直后的输入信号光进行起偏；带空间倾角的双折射光楔6将起偏器5产生的线偏振光再产生两个正交的线偏振光，使这两束正交的线偏振光具有沿光楔厚度变化方向呈线性分布的空间光程差，通过带空间倾角的双折射光楔6的二维空间楔角，实现低相干干涉条纹在水平和垂直方向上不同程度的缩放，在其中一个方向上对干涉条纹进行压缩，实现测量范围的扩大；在另一个方向上对局部干涉条纹进行展宽，实现测量分辨率的提高；检偏器7对经过带空间倾角的双折射光楔6后的两个相互正交的线偏振光进行同一方向的投影并产生干涉；利用面阵相机8对经过检偏器后产生的干涉条纹进行采集；利用信号处理单元9对面阵相机采集的干涉条纹进行处理，最终获取压力测量结果。
本发明还提出了一种高分辨率偏振低相干干涉系统的压力测量方法，具体包括以下步骤：
步骤一、宽带光源发出的光经过光纤耦合器到达光纤法珀传感器；
步骤二、被光纤法珀传感器调制过的光信号从耦合器的出口导出，经准直透镜准直后，经起偏器起偏成线偏振光，然后入射到带空间倾角的双折射光楔，起偏器的偏振轴方向与带空间倾角的双折射光楔的光轴方向成45度放置，在带空间倾角的双折射光楔 中该偏振光被分解成相互正交的两束线偏振光即o光和e光，两个分量在带空间倾角的双折射光楔中产生光程差
l(x，y)＝d(x，y)·(ne-no)，
其中，x为入射光点至光楔顶点的横向距离，y为入射光点至光楔顶点的纵向距离，no和ne分别为双折射晶体的o光折射率和e光折射率，d(x,y)为入射光点处的光楔厚度，并且表达式如下：
Figure PCTCN2016103524-appb-000001
其中，θ和
Figure PCTCN2016103524-appb-000002
分别为光楔在水平和垂直方向上的楔角，d0为光楔定点处的光楔厚度；
在其中一个方向通过设计大楔角对干涉条纹进行压缩，实现测量范围的扩大，在另一个方向通过设计微小楔角对局部干涉条纹进行展宽，实现测量分辨率的提高；
步骤三、经过与带空间倾角的双折射光楔的光轴方向成45度放置的检偏器，将透射过带空间倾角的双折射光楔的两束相互垂直的o光和e光重新在检偏方向上进行叠加，产生干涉条纹，利用面阵相机进行接收；
步骤四、信号处理单元对面阵相机输出的二维干涉条纹信号进行处理，通过大楔角方向上的低相干干涉信号得到初步的峰值位置，基于初步的峰值位置所在坐标，通过微小楔角方向上的低相干干涉信号得到精确的条纹峰值位置，最终提取出法珀腔长信息，并得到对应的压力测量结果，实现高分辨率的压力解调。
本发明有效地利用双折射效应构成光学杠杆，通过设计带空间倾角的双折射光楔的二维空间楔角，实现低相干干涉条纹在水平和垂直方向上不同程度的缩放；与现有技术相比，引入了双折射光楔在垂直方向上的空间楔角，并利用面阵相机进行信号接收，可实现同时满足大测量范围和高分辨率的压力解调。
附图说明
图1为基于面阵相机的高分辨率偏振低相干干涉压力测量装置结构示意图；
图2为带空间倾角的双折射光楔结构示意图；
图3为面阵相机接收到的11kPa、55kPa、101kPa、255kPa四个压力点下的单帧实验结果图像；
图4为101kPa压力下某一帧图像第1020行和第1044列的原始数据；
图5为101kPa下150帧图像第1020行数据处理所得结果波动情况；
图6为101kPa下150帧图像第1044列数据处理所得结果波动情况；
附图标记：1、宽带光源2、光纤耦合器3、光纤法珀传感器4、准直透镜5、起偏器6、带空间倾角的双折射光楔7、检偏器8、面阵相机9、信号处理单元。
具体实施方式
实施例1：一种基于面阵相机的高分辨率偏振低相干干涉压力测量装置
如图1所示，宽带光源1发出的光经过光纤耦合器2到达光纤法珀传感器3，被光纤法珀传感器3调制过的光信号从光纤耦合器2的出口导出，经准直透镜4准直后进入解调干涉仪，解调干涉仪由起偏器5、带空间倾角的双折射光楔6和检偏器7组成，由于带空间倾角的双折射光楔6的双折射效应，光信号通过带空间倾角的双折射光楔6形成空间低相干干涉条纹并被面阵相机8接收，信号处理单元9对面阵相机8输出的干涉条纹信号进行处理，当带空间倾角的双折射光楔6引起的光程差和光纤法珀传感器3引起的光程差相匹配时，会在面阵相机8相应的局部区域产生明显的低相干干涉条纹。
在此实验过程中，宽带光源1采用中心波长为750nm的SLED光源模块，光纤耦合器2采用2×2多模耦合器，起偏器5和检偏器7采用格兰汤姆森棱镜，带空间倾角的双折射光楔6采用铌酸锂光楔，采用面阵CCD做为面阵相机8，其像元大小为3.45μm*3.45μm，像元数量为2456*2058。
实施例2：一种基于面阵相机的高分辨率偏振低相干干涉压力测量方法
上述基于面阵相机的高分辨率偏振低相干干涉装置的压力测量方法如下：
步骤一、宽带光源1发出的光经过光纤耦合器2到达光纤法珀传感器3，光纤法珀传感器3用于感受外界大气压力，其法珀腔的两个反射面构成了传感干涉仪，法珀腔两个反射面之间的距离与大气压力成线性关系；
步骤二、被光纤法珀传感器3调制过的光信号从光纤耦合器2的出口导出，经准直透镜准直4后，再经起偏器5起偏成线偏振光，然后入射到带空间倾角的双折射光楔6，起偏器5的偏振轴方向与带空间倾角的双折射光楔6的光轴方向成45度放置，在带空间倾角的双折射光楔6中该偏振光被分解成相互正交的两束线偏振光(o光和e光)，经过相同的传输距离o光和e走过的光程不同，两个分量在带空间倾角的双折射光楔6中中产生光程差l(x，y)＝d(x，y)·(ne-no)，，其中，x为入射光点至光楔顶点的横向距离，y为入射光点至光楔顶点的纵向距离，no和ne分别为双折射晶体的o光折射率和e光折射率，d(x,y)为入射光点处的光楔厚度，
Figure PCTCN2016103524-appb-000003
其中，θ和
Figure PCTCN2016103524-appb-000004
分别为光楔在水平和垂直方向上的倾角，d0为光楔定点处的光楔厚度，利用带空间倾角的双折射光楔6的光学杠杆效应，实现低相干干涉条纹在水平和垂直方向上不同程度的缩放，在水平方向通过设计较大的楔角对干涉条纹进行压缩，实现测量范围的扩大，在垂直方向通过设计微小楔角对局部干涉条纹进行展宽，实现测量分辨率的提高；在实验过程中，所用铌酸锂光楔水平方向楔角θ＝4°；垂直方向倾角
Figure PCTCN2016103524-appb-000005
d0＝1.5mm，所以面阵相机8接收面上某一点对应的光楔厚度可以表示为：
d(x，y)＝x tan 4°+y tan 1°+1.5mm≈0.0699x+0.0175y+1.5mm
步骤三、经过与带空间倾角的双折射光楔6的光轴方向成45度放置的检偏器7，将透射过带空间倾角的双折射光楔6的两束相互垂直的o光和e光重新在检偏方向上进行叠加，产生干涉条纹，利用面阵相机8进行接收；
步骤四、信号处理单元9对面阵相机8输出的二维干涉条纹信号进行处理，首先在大楔角方向，即水平方向提取行数据，通过处理大楔角方向上的低相干干涉信号得到初步的峰值位置，基于初步峰值位置所在坐标，在微小楔角方向，即垂直方向上提取列数 据，通过微小楔角方向上的低相干干涉信号得到精确的条纹峰值位置，最终提取出法珀腔长信息，并得到对应的压力测量结果，实现高分辨率的压力解调。
实验过程中，将光纤法珀传感器放置在压力舱中，压力变化范围为5kPa～265kPa，变化步长为2kPa，图3为11kPa、55kPa、101kPa、255kPa四个压力点下的单帧实验结果图像，可以看出中央条纹位置随压力变化的单向移动情况。
针对101kPa压力下某一帧图像(图3(c))提取第1020行数据(原始信号如图4(a))，计算得出中央条纹最大值位置为x＝1044，即条纹峰值位置初步定位于该行第1044个像元处附近；基于初步峰值位置，进行垂直方向分析，选择第1044列信号(原始信号如图4(b))进行处理，经计算可得中央条纹最大值的较精确位置在该列第1077个像元处；
对101kpa下所得150帧图像，都取第1020行信号进行数据处理，所得结果如图5所示，中央条纹最大值的位置在该行第1043～1046个像元范围内，对应的法珀腔长变化量为0.03μm，能够初步定位条纹峰值位置；
对101kpa下所得150帧图像，都取第1044列信号进行数据处理，所得结果如图6所示，中央条纹最大值的位置在该列第1077～1079个像元范围内，对应的法珀腔长变化量为0.005μm，测量得到的腔长值波动较小，可以提高解调分辨率。
在本发明的基于面阵相机的高分辨率偏振低相干干涉系统中：
宽带光源可以是LED光源，也可以是SLD光源；
双折射晶体可以采用铌酸锂晶体，氟化镁晶体，冰洲石晶体，YVO4晶体；
起偏器和检偏器可以是格兰-泰勒棱镜，格兰-汤姆逊棱镜等偏振棱镜，也可以是偏光片；
面阵相机可以是面阵CMOS相机，也可以是面阵CCD相机；
处理单元除了可采用计算机实现外，也可采用嵌入式系统实现；
上述的光纤光学器件部分也可以采用对应的空间光学器件代替。

Claims (2)

  1. 一种高分辨率偏振低相干干涉压力测量装置，其特征在于，从输入端到输出端，该装置依次设置宽带光源(1)、光纤耦合器(2)、光纤法珀传感器(3)、准直透镜(4)、起偏器(5)、带空间倾角的双折射光楔(6)、检偏器(7)、面阵相机(8)以及信号处理单元(9)，其中：光纤耦合器(2)将宽带光源(1)发出的光引入到光纤法珀传感器(3)，并将光纤法珀传感器(3)返回的光引入到干涉解调光路中；光纤法珀传感器(3)将压力变化转化为法珀腔腔长变化，不同压力对应不同法珀腔腔长；所述准直透镜(4)、起偏器(5)、带空间倾角的双折射光楔(6)、检偏器(7)、面阵相机(8)构成干涉解调器；准直透镜(4)设置在干涉解调光路最前端，对光束进行会聚准直；起偏器(5)将准直透镜准直后的输入信号光进行起偏；带空间倾角的双折射光楔(6)将起偏器(5)产生的线偏振光再产生两个正交的线偏振光，使这两束正交的线偏振光具有沿光楔厚度变化方向呈线性分布的空间光程差，通过带空间倾角的双折射光楔(6)的二维空间楔角，实现低相干干涉条纹在水平和垂直方向上不同程度的缩放，在其中一个方向上对干涉条纹进行压缩，实现测量范围的扩大；在另一个方向上对局部干涉条纹进行展宽，实现测量分辨率的提高；检偏器(7)对经过带空间倾角的双折射光楔(6)后的两个相互正交的线偏振光进行同一方向的投影并产生干涉；利用面阵相机(8)对经过检偏器后产生的干涉条纹进行采集；利用信号处理单元(9)对面阵相机采集的干涉条纹进行处理，最终获取压力测量结果。
  2. 一种高分辨率偏振低相干干涉系统的压力测量方法，其特征在于，该方法具体包括以下步骤：
    步骤一、宽带光源发出的光经过光纤耦合器到达光纤法珀传感器；
    步骤二、被光纤法珀传感器调制过的光信号从耦合器的出口导出，经准直透镜准直后，经起偏器起偏成线偏振光，然后入射到带空间倾角的双折射光楔，起偏器的偏振轴方向与带空间倾角的双折射光楔的光轴方向成45度放置，在带空间倾角的双折射光楔中该偏振光被分解成相互正交的两束线偏振光即o光和e光，两个分量在带空间倾角的双折射光楔中产生光程差
    l(x，y)＝d(x，y)·(ne-no)，
    其中，x为入射光点至光楔顶点的横向距离，y为入射光点至光楔顶点的纵向距离， no和ne分别为双折射晶体的o光折射率和e光折射率，d(x,y)为入射光点处的光楔厚度，并且表达式如下：
    Figure PCTCN2016103524-appb-100001
    其中，θ和
    Figure PCTCN2016103524-appb-100002
    分别为光楔在水平和垂直方向上的楔角，d0为光楔定点处的光楔厚度；
    在其中一个方向通过设计大楔角对干涉条纹进行压缩，实现测量范围的扩大，在另一个方向通过设计微小楔角对局部干涉条纹进行展宽，实现测量分辨率的提高；
    步骤三、经过与带空间倾角的双折射光楔的光轴方向成45度放置的检偏器，将透射过带空间倾角的双折射光楔的两束相互垂直的o光和e光重新在检偏方向上进行叠加，产生干涉条纹，利用面阵相机进行接收；
    步骤四、信号处理单元对面阵相机输出的二维干涉条纹信号进行处理，通过大楔角方向上的低相干干涉信号得到初步的峰值位置，基于初步的峰值位置所在坐标，通过微小楔角方向上的低相干干涉信号得到精确的条纹峰值位置，最终提取出法珀腔长信息，并得到对应的压力测量结果，实现高分辨率的压力解调。
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112179505A (zh) * 2020-09-23 2021-01-05 中国科学院光电技术研究所 一种基于楔形平板剪切干涉仪图像处理装置及方法
CN114877921A (zh) * 2021-07-13 2022-08-09 中国航空工业集团公司北京长城计量测试技术研究所 一种光纤光栅与法帕腔复合传感器信号解耦方法和装置
WO2024146600A1 (zh) * 2023-01-04 2024-07-11 北京佰为深科技发展有限公司 干涉解调装置和干涉测量系统

Families Citing this family (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL2014518B1 (en) * 2015-03-25 2017-01-17 Fugro Tech Bv A device for measuring fluid parameters, a method for measuring fluid parameters and a computer program product.
CN105466621B (zh) * 2015-12-28 2018-02-13 天津大学 一种高分辨率偏振低相干干涉压力测量装置及方法
CN106017519B (zh) * 2016-05-05 2018-05-22 重庆大学 一种光纤法珀传感器解调系统及方法
US10516879B2 (en) 2016-08-12 2019-12-24 Avegant Corp. Binocular display with digital light path length modulation
US10809546B2 (en) 2016-08-12 2020-10-20 Avegant Corp. Digital light path length modulation
US10185153B2 (en) 2016-08-12 2019-01-22 Avegant Corp. Orthogonal optical path length extender
US10379388B2 (en) 2016-08-12 2019-08-13 Avegant Corp. Digital light path length modulation systems
US10401639B2 (en) 2016-08-12 2019-09-03 Avegant Corp. Method and apparatus for an optical path length extender
US10187634B2 (en) 2016-08-12 2019-01-22 Avegant Corp. Near-eye display system including a modulation stack
US10057488B2 (en) * 2016-08-12 2018-08-21 Avegant Corp. Image capture with digital light path length modulation
US10789472B1 (en) * 2017-06-14 2020-09-29 Amazon Technologies, Inc. Multiple image processing and sensor targeting for object detection
CN107401982B (zh) * 2017-07-26 2019-07-09 淮阴师范学院 基于低相干光干涉法的透镜中心厚度的非接触测量方法
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CN115427778B (zh) * 2020-04-20 2026-02-03 北京佰为深科技发展有限公司 法珀传感器腔长解调系统和法珀传感器腔长解调方法
CN112284430B (zh) * 2020-10-23 2022-04-08 天津大学 一种基于光载微波干涉的多相流多参量光纤探测装置
CN116136436A (zh) * 2021-11-17 2023-05-19 北京杰福科技有限公司 玻璃边缘应力检测仪、测算方法及计算机存储介质和设备
WO2023159395A1 (zh) * 2022-02-23 2023-08-31 北京佰为深科技发展有限公司 光纤法布里珀罗传感器解调系统
CN115597644B (zh) * 2022-10-08 2025-03-21 南京航空航天大学 基于双折射干涉仪的法珀传感器解调色散补偿装置与方法
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002090111A (ja) * 2000-09-20 2002-03-27 Kyowa Electron Instr Co Ltd 光ファイバ干渉センサ、光ファイバ干渉センサの信号処理システム、信号処理方法および記録媒体
EP1890123A2 (en) * 2006-08-18 2008-02-20 National Institute of Advanced Industrial Science and Technology AE/ultrasound detection system, and material monitoring apparatus and nondestructive inspection apparatus equipped the system
CN102052902A (zh) * 2010-12-10 2011-05-11 天津大学 一种高精度大量程低相干干涉位移解调装置及其解调方法
CN102829902A (zh) * 2012-08-09 2012-12-19 天津大学 阵列式多通道光纤法珀压力传感装置及压力测量方法
CN103542870A (zh) * 2013-10-12 2014-01-29 天津大学 交流调制型低相干干涉解调系统及其解调方法
CN105466621A (zh) * 2015-12-28 2016-04-06 天津大学 一种高分辨率偏振低相干干涉压力测量装置及方法

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006058423A1 (en) * 2004-11-30 2006-06-08 Opsens Inc. Birefringent optical temperature sensor and method
CN102322801B (zh) * 2011-08-09 2012-12-12 天津大学 高信噪比摆动式低相干干涉位移解调装置及其解调方法
CN102519498B (zh) * 2011-12-07 2014-06-04 天津大学 基于任意极值的低相干干涉解调方法
CN103267536B (zh) * 2013-05-07 2015-08-26 天津大学 基于色散特征和包络峰值的低相干干涉解调方法
CN103712781B (zh) * 2013-12-25 2016-03-30 天津大学 双折射光楔光轴方向的多入射角偏振干涉测量装置及方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002090111A (ja) * 2000-09-20 2002-03-27 Kyowa Electron Instr Co Ltd 光ファイバ干渉センサ、光ファイバ干渉センサの信号処理システム、信号処理方法および記録媒体
EP1890123A2 (en) * 2006-08-18 2008-02-20 National Institute of Advanced Industrial Science and Technology AE/ultrasound detection system, and material monitoring apparatus and nondestructive inspection apparatus equipped the system
CN102052902A (zh) * 2010-12-10 2011-05-11 天津大学 一种高精度大量程低相干干涉位移解调装置及其解调方法
CN102829902A (zh) * 2012-08-09 2012-12-19 天津大学 阵列式多通道光纤法珀压力传感装置及压力测量方法
CN103542870A (zh) * 2013-10-12 2014-01-29 天津大学 交流调制型低相干干涉解调系统及其解调方法
CN105466621A (zh) * 2015-12-28 2016-04-06 天津大学 一种高分辨率偏振低相干干涉压力测量装置及方法

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112179505A (zh) * 2020-09-23 2021-01-05 中国科学院光电技术研究所 一种基于楔形平板剪切干涉仪图像处理装置及方法
CN112179505B (zh) * 2020-09-23 2022-08-02 中国科学院光电技术研究所 一种基于楔形平板剪切干涉仪图像处理装置及方法
CN114877921A (zh) * 2021-07-13 2022-08-09 中国航空工业集团公司北京长城计量测试技术研究所 一种光纤光栅与法帕腔复合传感器信号解耦方法和装置
CN114877921B (zh) * 2021-07-13 2022-09-09 中国航空工业集团公司北京长城计量测试技术研究所 一种光纤光栅与法帕腔复合传感器信号解耦方法和装置
WO2024146600A1 (zh) * 2023-01-04 2024-07-11 北京佰为深科技发展有限公司 干涉解调装置和干涉测量系统

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