CN102645316A - Large-caliber deflection type device for checking radial shear interference under center shielding condition and method for checking radial shear interference - Google Patents

Abstract

Translated fromChinese

本发明公开了一种中心遮挡情况下的大口径偏折型径向剪切干涉检测装置及其方法。本发明的技术特点是在传统径向剪切干涉检测方法的基础上，通过提高望远镜系统的剪切率，并利用反射镜在竖直方向的倾斜将缩束光斑移至扩束光斑的边缘区域，使缩束光斑脱离扩束光斑中因目标物遮挡所形成的阴影处形成干涉，实现了有目标物中心遮挡情况下对特定空间区域的径向剪切干涉检测。本发明的优点在于解决了采用传统径向剪切干涉方法无法对含有目标物中心遮挡的区域进行波前检测的难题，同时，由于干涉区域移至扩束光斑边缘，使得干涉图的处理可以采用较为简单的相位解包方法，而非径向剪切波面迭代重构，在一定程度上简化了干涉图的处理过程，缩短了处理时间。

The invention discloses a large-diameter deflection type radial shear interference detection device and a method thereof under the condition of central occlusion. The technical feature of the present invention is that on the basis of the traditional radial shear interference detection method, by increasing the shear rate of the telescope system, and utilizing the inclination of the mirror in the vertical direction, the reduced beam spot is moved to the edge area of the expanded beam spot , so that the narrowed beam spot is separated from the shadow formed by the target object in the expanded beam spot to form interference, and the radial shear interference detection of a specific space area is realized in the case of the center of the target object. The advantage of the present invention is that it solves the problem that the traditional radial shearing interference method cannot perform wavefront detection on the region containing the center of the target object. The relatively simple phase unwrapping method, rather than the iterative reconstruction of the radial shear wave surface, simplifies the processing of the interferogram to a certain extent and shortens the processing time.

Description

Translated fromChinese

中心遮挡情况下的大口径偏折型径向剪切干涉检测装置及其方法Large-aperture deflection type radial shear interference detection device and method under central occlusion

技术领域technical field

    本发明涉及一种中心遮挡情况下的大口径偏折型径向剪切干涉检测装置及其方法。The present invention relates to a large-diameter deflection type radial shear interference detection device and its method under the condition of central occlusion.

背景技术Background technique

在高超音速流场空气动力学测试中，对风洞中目标物周围流场的精确测量是一个亟待解决的问题。传统的较为成熟的方法有阴影法和纹影法，其中阴影法对流场变化的二阶导数敏感，而纹影法对流场变化的一阶导数敏感，但由于它们采用的是几何光学的原理，其在测量精度上仍有待提高。对高速流场区域采用径向剪切干涉法进行检测也是一种行之有效的手段。首先，径向剪切干涉采用了光学干涉的方法，将经过流场后畸变波前的检测精度提高到了光学波长量级；其次，径向剪切干涉仪属于准共路干涉系统，具有较高的抗干扰能力，保证了风洞检测中高噪音、高振动的环境下仍然能够得到较为稳定的干涉条纹，从而确保了实验结果的正确性；另外，采用径向剪切干涉的方法经过后期的数据处理后最终得到的数据为经过流场检测光束的波前位相分布信息，可以在此基础上进行空间折射率场或密度场的重构，这是采用光强分布测量的阴影法和纹影法所不能具备的。In the aerodynamic test of hypersonic flow field, the accurate measurement of the flow field around the target in the wind tunnel is an urgent problem to be solved. The traditional more mature methods are shadow method and schlieren method, among which the shadow method is sensitive to the second order derivative of the flow field change, and the schlieren method is sensitive to the first order derivative of the flow field change, but because they use geometric optics However, its measurement accuracy still needs to be improved. It is also an effective method to detect the high-speed flow field area by radial shear interferometry. Firstly, the radial shearing interferometer adopts the method of optical interference, which improves the detection accuracy of the distorted wavefront after passing through the flow field to the optical wavelength level; secondly, the radial shearing interferometer is a quasi-common path interference system with high The anti-interference ability ensures that relatively stable interference fringes can still be obtained in high-noise and high-vibration environments in wind tunnel testing, thereby ensuring the correctness of experimental results; The final data obtained after processing is the wavefront phase distribution information of the flow field detection beam, on which the spatial refractive index field or density field can be reconstructed. This is the shadow method and schlieren method of light intensity distribution measurement unavailable.

对于高速流场检测来说，对风洞中心目标物周围流场的检测是较为常见的情形，但是由于传统的径向剪切干涉法采用缩束光斑与扩束光斑共轴同心的配置，缩束光斑将落在扩束光斑中目标物所投射的阴影区内，导致干涉条纹无法形成。因此，就需要提出一种能够在目标物中心遮挡情况下的对周围流场进行检测的干涉检测方法。For the detection of high-speed flow field, the detection of the flow field around the target in the center of the wind tunnel is a relatively common situation. The beam spot will fall in the shadow area cast by the target in the expanded beam spot, resulting in the failure to form interference fringes. Therefore, it is necessary to propose an interference detection method capable of detecting the surrounding flow field when the center of the object is blocked.

发明内容Contents of the invention

本发明的目的是克服现有技术的不足，提供一种中心遮挡情况下的大口径偏折型径向剪切干涉检测装置及其方法。The purpose of the present invention is to overcome the deficiencies of the prior art, and provide a large-diameter deflection type radial shear interference detection device and its method under the condition of central occlusion.

中心遮挡情况下的大口径偏折型径向剪切干涉检测装置包括激光器、准直扩束系统、目标物、待测区域、分光镜、第一反射镜、高剪切比大口径望远镜系统、第二反射镜、成像透镜和探测器；其中，目标物置于待测区域中心，激光器、准直扩束系统、目标物、分光镜、第一反射镜、高剪切比大口径望远镜系统、第二反射镜、分光镜、成像透镜以及探测器在第一条光路中顺序排列；激光器、准直扩束系统、目标物、分光镜、第二反射镜、高剪切比大口径望远镜系统、第一反射镜、分光镜、成像透镜以及探测器在第二条光路中顺序排列；第一反射镜和第二反射镜均与竖直方向成夹角                                               

，为

，使经过高剪切比大口径望远镜系统的缩束光和扩束光偏离原光轴传播。The large-aperture deflection-type radial shear interference detection device under the condition of central occlusion includes a laser, a collimated beam expander system, a target, an area to be measured, a beam splitter, a first reflector, a high-shear ratio large-aperture telescope system, The second reflector, imaging lens and detector; wherein, the target is placed in the center of the area to be measured, the laser, the collimating beam expander system, the target, the beam splitter, the first reflector, the high-shear ratio large-aperture telescope system, the second The second reflector, beam splitter, imaging lens and detector are arranged sequentially in the first optical path; the laser, collimator beam expander system, target, beam splitter, second reflector, high shear ratio large-aperture telescope system, the second A reflector, a beam splitter, an imaging lens and a detector are arranged sequentially in the second optical path; the first reflector and the second reflector both form an included angle with the vertical direction

, for

, so that the reduced beam and expanded beam of the high-shear ratio large-aperture telescope system deviate from the original optical axis to propagate.

中心遮挡情况下的大口径偏折型径向剪切干涉检测方法包括如下步骤：The large-aperture deflection type radial shear interference detection method in the case of central occlusion includes the following steps:

(1) 调节激光器、准直扩束系统、分光镜、第一反射镜、高剪切比大口径望远镜系统、第二反射镜、成像透镜、探测器等高同轴，调节准直扩束系统使得大口径平行光出射；(1) Adjust the laser, collimator beam expander system, beam splitter, first reflector, high-shear ratio large-aperture telescope system, second reflector, imaging lens, detector, etc., and adjust the collimator beam expander system Make the large-aperture parallel light exit;

(2) 调节分光镜的角度使得经过分光镜的透射光和反射光互成90°夹角，且分别照射在第一反射镜和第二反射镜上；(2) Adjust the angle of the beam splitter so that the transmitted light and reflected light passing through the beam splitter form an angle of 90° with each other, and irradiate on the first reflector and the second reflector respectively;

(3) 调节第一反射镜和第二反射镜在水平方向上的角度和竖直方向上的倾角，使得第一条光路和第二条光路经过成像透镜后的光斑在探测器上重合；(3) Adjust the angle of the first reflector and the second reflector in the horizontal direction and the inclination angle in the vertical direction, so that the light spots of the first light path and the second light path after passing through the imaging lens coincide on the detector;

(3) 在第一反射镜和第二反射镜之间加入高剪切比大口径望远镜系统，调节该望远镜系统的位置和倾角使得探测器上的缩束光斑与扩束光斑同心，并产生干涉条纹；(3) Add a high-shear ratio large-aperture telescope system between the first reflector and the second reflector, and adjust the position and inclination of the telescope system so that the beam-shrinking spot on the detector is concentric with the beam-expanding spot and produces interference stripe;

(4) 调节第一反射镜和第二反射镜在竖直方向上的倾角，使得探测器上的缩束光斑移出扩束光斑的目标物阴影处并产生干涉；(4) Adjust the inclination angle of the first reflector and the second reflector in the vertical direction, so that the beam shrinkage spot on the detector moves out of the target shadow of the beam expander spot and interferes;

(5) 采集探测器上接收到的干涉图，将扩束波前参与干涉的部分光波近似为平面波，对干涉图进行相位解包，得到干涉图的相位数据。(5) Collect the interferogram received on the detector, approximate the part of the light waves involved in the interference of the expanded beam front as a plane wave, unpack the phase of the interferogram, and obtain the phase data of the interferogram.

本发明采用将缩束光路和扩束光路与光轴偏离的方法，使得探测器上的缩束光斑可以移到扩束光斑的边缘区域，解决了采用传统径向剪切干涉方法无法对含有目标物中心遮挡的空间区域进行波前检测的难题，又由于所述的高剪切比大口径望远镜系统具有较高的剪切比，可以将扩束波前参与干涉的部分光波近似为平面波来处理，使得干涉图的处理可以采用较为简单的传统泰曼格林干涉系统的相位解包方法，即看成是一路检测光波和一路参考平面光波的干涉，而无需使用较为耗时的径向剪切波面迭代重构算法，在一定程度上简化了实验数据的处理过程，缩短了处理时间。The invention adopts the method of deviating the reduced beam optical path and the expanded beam optical path from the optical axis, so that the reduced beam spot on the detector can be moved to the edge area of the expanded beam spot, which solves the problem that the conventional radial shearing interference method cannot It is difficult to detect the wavefront in the space area blocked by the center of the object, and because the high shear ratio large-aperture telescope system has a high shear ratio, the part of the light wave that participates in the interference of the expanded beam wavefront can be approximated as a plane wave for processing , so that the processing of the interferogram can adopt the relatively simple phase unpacking method of the traditional Tieman Green interferometric system, that is, it can be regarded as the interference of one detection light wave and one reference plane light wave, without using the more time-consuming radial shear wave front The iterative reconstruction algorithm simplifies the processing of experimental data to a certain extent and shortens the processing time.

附图说明Description of drawings

图1是中心遮挡情况下的大口径偏折型径向剪切干涉检测装置结构示意图；Figure 1 is a schematic structural diagram of a large-diameter deflection type radial shear interference detection device under the condition of central occlusion;

图2是本发明的缩束光束和扩束光束偏离光轴通过高剪切比大口径望远镜系统的光路示意图；Fig. 2 is the schematic diagram of the optical path of the reduced beam and the expanded beam of the present invention deviated from the optical axis through the high shear ratio large aperture telescope system;

图3是中心遮挡情况下的大口径偏折型径向剪切干涉检测方法的流程图；   Fig. 3 is a flow chart of the large-aperture deflection type radial shear interference detection method in the case of central occlusion;

图4是探测器前缩束光斑和扩束光斑以及其中目标物阴影位置的示意图与干涉图；Fig. 4 is a schematic diagram and an interferogram of the reduced beam spot and the expanded beam spot in front of the detector and the shadow position of the target therein;

图5是经截取后的探测器接收到的干涉图；Fig. 5 is the interferogram received by the detector after interception;

图6 是采用干涉位相解调方法后得到的去除目标物遮挡部分的波前位相分布图。Figure 6 is the phase distribution diagram of the wavefront obtained by removing the occlusion part of the target object after using the interferometric phase demodulation method.

具体实施方式Detailed ways

如图1、2所示，中心遮挡情况下的大口径偏折型径向剪切干涉检测装置包括激光器S1、准直扩束系统S2、目标物S3、待测区域S4、分光镜S5、第一反射镜S6、高剪切比大口径望远镜系统S7、第二反射镜S8、成像透镜S9和探测器S10；其中，目标物S3置于待测区域S4中心，激光器S1、准直扩束系统S2、目标物S3、分光镜S5、第一反射镜S6、高剪切比大口径望远镜系统S7、第二反射镜S8、分光镜S5、成像透镜S9以及探测器S10在第一条光路中顺序排列；激光器S1、准直扩束系统S2、目标物S3、分光镜S5、第二反射镜S8、高剪切比大口径望远镜系统S7、第一反射镜S6、分光镜S5、成像透镜S9以及探测器S10在第二条光路中顺序排列；第一反射镜S6和第二反射镜S8均与竖直方向成夹角

，

为

，使经过高剪切比大口径望远镜系统S7的缩束光和扩束光偏离原光轴传播。As shown in Figures 1 and 2, the large-diameter deflection type radial shear interference detection device under the condition of central occlusion includes a laser S1, a collimator beam expander system S2, a target S3, an area to be measured S4, a beam splitter S5, and a A mirror S6, a high-shear ratio large-aperture telescope system S7, a second mirror S8, an imaging lens S9, and a detector S10; wherein, the target S3 is placed in the center of the area S4 to be measured, and the laser S1 and the collimating beam expander system S2, target S3, beam splitter S5, first mirror S6, high shear ratio large aperture telescope system S7, second mirror S8, beam splitter S5, imaging lens S9 and detector S10 in the first optical path Arrangement; laser S1, collimating beam expander system S2, target S3, beam splitter S5, second reflector S8, high shear ratio large aperture telescope system S7, first reflector S6, beam splitter S5, imaging lens S9 and Detectors S10 are arranged sequentially in the second optical path; both the first reflector S6 and the second reflector S8 form an angle with the vertical direction

,

for

, so that the reduced beam and expanded beam of the high-shear ratio large-aperture telescope system S7 propagate away from the original optical axis.

中心遮挡情况下的大口径偏折型径向剪切干涉检测方法包括如下步骤：The large-aperture deflection type radial shear interference detection method in the case of central occlusion includes the following steps:

(1) 调节激光器S1、准直扩束系统S2、分光镜S5、第一反射镜S6、高剪切比大口径望远镜系统S7、第二反射镜S8、成像透镜S9、探测器S10等高同轴，调节准直扩束系统S2使得大口径平行光出射；(1) Adjusting laser S1, collimating beam expander system S2, beam splitter S5, first reflector S6, high shear ratio large aperture telescope system S7, second reflector S8, imaging lens S9, detector S10, etc. Axis, adjust the collimator beam expander system S2 to make the large-aperture parallel light exit;

(2) 调节分光镜S5的角度使得经过分光镜S5的透射光和反射光互成90°夹角，且分别照射在第一反射镜S6和第二反射镜S8上；(2) Adjust the angle of the beam splitter S5 so that the transmitted light and the reflected light through the beam splitter S5 form a 90° angle with each other, and are respectively irradiated on the first reflector S6 and the second reflector S8;

(3) 调节第一反射镜S6和第二反射镜S8在水平方向上的角度和竖直方向上的倾角，使得第一条光路和第二条光路经过成像透镜S9后的光斑在探测器S10上重合；(3) Adjust the angle of the first reflector S6 and the second reflector S8 in the horizontal direction and the inclination angle in the vertical direction, so that the light spot after the first optical path and the second optical path pass through the imaging lens S9 is on the detector S10 Overlap;

(3) 在第一反射镜S6和第二反射镜S8之间加入高剪切比大口径望远镜系统S7，调节该望远镜系统的位置和倾角使得探测器S10上的缩束光斑与扩束光斑同心，并产生干涉条纹；(3) Add high-shear ratio large-aperture telescope system S7 between the first reflector S6 and the second reflector S8, and adjust the position and inclination of the telescope system so that the beam-shrinking spot on the detector S10 is concentric with the beam-expanding spot , and produce interference fringes;

(4) 调节第一反射镜S6和第二反射镜S8在竖直方向上的倾角，使得探测器S10上的缩束光斑移出扩束光斑的目标物阴影处并产生干涉；(4) Adjust the inclination angle of the first reflector S6 and the second reflector S8 in the vertical direction, so that the beam shrinkage spot on the detector S10 moves out of the target shadow of the beam expander spot and produces interference;

(5) 采集探测器S10上接收到的干涉图，将扩束波前参与干涉的部分光波近似为平面波，对干涉图进行相位解包，得到干涉图的相位数据。(5) Collect the interferogram received by the detector S10, approximate the part of the light waves involved in the interference of the expanded beam wavefront as a plane wave, unpack the phase of the interferogram, and obtain the phase data of the interferogram.

如图2所示，表示了经过反射镜S6和反射镜S8反射的缩束光束和扩束光束偏离原光轴通过高剪切比大口径望远镜系统S7的光路。在加入高剪切比大口径望远镜系统S7并使得探测器S10上的缩束光斑与扩束光斑同心产生干涉条纹后，反射镜S6和反射镜S8与竖直方向的夹角为0。微调反射镜S6使其与竖直方向有一个

的夹角，使缩束光斑上移，此时干涉条纹消失。可以发现激光器S1端面上的馈光也同时移出了激光器出射窗口。微调反射镜S8使馈光返回激光器出射窗口附近，干涉条纹再次出现，而此时的缩束光斑与扩束光斑已不再同心，而是稍微有所上移。继续微调反射镜S6使其与竖直方向的夹角

增大，缩束光斑继续上移，再微调反射镜S8使得馈光返回激光器出射窗口，出现干涉条纹，如此反复操作，直至缩束光斑移至扩束光斑的边缘区域，得到的干涉条纹即为中心遮挡情况下的大口径偏折型径向剪切干涉图数据。As shown in FIG. 2 , it shows the optical path of the reduced beam and expanded beam reflected by the mirror S6 and the mirror S8 deviated from the original optical axis and passes through the high shear ratio large-aperture telescope system S7. After adding the high-shear ratio large-aperture telescope system S7 and making the beam-shrinking spot on the detector S10 concentric with the beam-expanding spot to generate interference fringes, the angle between the mirror S6 and the mirror S8 and the vertical direction is 0. Fine-tune mirror S6 so that it has a

The included angle makes the beam shrinkage spot move up, and the interference fringes disappear at this time. It can be found that the fed light on the end face of the laser S1 is also moved out of the laser exit window at the same time. Fine-tuning the mirror S8 makes the fed light return to near the exit window of the laser, and the interference fringe appears again. At this time, the beam shrinking spot and beam expanding spot are no longer concentric, but slightly moved up. Continue to fine-tune the mirror S6 to make its angle with the vertical direction

Increase, the shrinking spot continues to move up, and then fine-tune the mirror S8 to make the fed light return to the laser exit window, and interference fringes appear. Repeat this operation until the shrinking spot moves to the edge area of the expanding spot, and the obtained interference fringes are Large-aperture deflection-type radial shear interferogram data under central occlusion.

由于所述的高剪切比大口径望远镜系统S7采用较高的剪切比，且最后的干涉条纹位于扩束波前的边缘区域，可以将扩束波前参与干涉的部分光波近似为平面波来处理，使得干涉图的处理可以采用较为简单的传统泰曼格林干涉系统的相位解包方法，即看成是一路检测光波和一路参考平面光波的干涉，而无需使用较为耗时的径向剪切波面迭代重构算法，在一定程度上简化了实验数据的处理过程，缩短了处理时间。Since the high-shear ratio large-aperture telescope system S7 adopts a higher shear ratio, and the final interference fringes are located at the edge region of the expanded beam front, the part of the light waves participating in the interference of the expanded beam front can be approximated as a plane wave. processing, so that the processing of the interferogram can adopt the relatively simple phase unwrapping method of the traditional Tieman Green interferometric system, that is, it can be regarded as the interference of one detection light wave and one reference plane light wave, without using the more time-consuming radial shearing The wavefront iterative reconstruction algorithm simplifies the processing of experimental data to a certain extent and shortens the processing time.

实施例Example

本发明应用于一基于中心遮挡情况下的大口径偏折型径向剪切干涉检测方法实例描述如下。An example of the application of the present invention to a large-aperture deflection type radial shear interference detection method based on central occlusion is described as follows.

图1是中心遮挡情况下的大口径偏折型径向剪切干涉检测系统的光路布局。实施例的被测区域大小为f70mm，其中心位置有一钝锥形状的目标物。采用的激光器为He-Ne激光光源，激光器S1经准直扩束系统S2产生大口径的平行光，经过目标物S3置于中心位置的检测区域S4，经分光镜S5分束后一路射向反射镜S6，经过高剪切比大口径望远镜系统S7缩束后射向反射镜S8，通过分光镜S5透射进入成像透镜S9；另一路光射向反射镜S8，经过高剪切比大口径望远镜系统S7扩束后射向反射镜S6，通过分光镜S5反射进入成像透镜S9，经分光镜S5透射或反射进入成像透镜S9的两束光在探测器S10上得到干涉条纹。其中，反射镜S6和反射镜S8均与竖直方向成夹角，

为，使得经过高剪切比大口径望远镜系统S7的缩束和扩束光偏离原光轴传播。Fig. 1 is the optical path layout of the large-aperture deflection type radial shear interference detection system under the condition of central occlusion. The size of the measured area in the embodiment is f70mm, and there is a blunt cone-shaped target in the center. The laser used is a He-Ne laser light source. The laser S1 generates large-diameter parallel light through the collimator beam expander system S2, passes through the detection area S4 where the target S3 is placed in the center, and is split by the beam splitter S5. The mirror S6, after being narrowed by the high-shear ratio large-aperture telescope system S7, shoots to the reflector S8, transmits through the beam splitter S5 and enters the imaging lens S9; the other light shoots to the reflector S8, and passes through the high-shear ratio large-aperture telescope system The beam of S7 is expanded and directed to the mirror S6, reflected by the beam splitter S5 into the imaging lens S9, and the two beams of light transmitted or reflected by the beam splitter S5 into the imaging lens S9 get interference fringes on the detector S10. Wherein, the mirror S6 and the mirror S8 both form an included angle with the vertical direction ,

for , so that the narrowed and expanded beams of the high-shear ratio large-aperture telescope system S7 propagate away from the original optical axis.

表一为实施例中的有效测量口径、剪切比等指标参数Table 1 is the index parameters such as effective measuring aperture, shear ratio in the embodiment

有效测量口径Effective measuring aperture望远镜系统剪切比Telescope System Shear RatioCCD像素数CCD pixels70mm70mm16:116:11024 × 10241024 × 1024

所述的偏折型径向剪切干涉体系中，标准平行光源的质量对于后续测量检测精度有着重要影响。实施例中，利用一双凹透镜与一双分离物镜组成来组成准直扩束系统S2，最后可以获得约Φ70mm的平行光束。通过一个精密五维调整机构可以调整双凹透镜与双分离物镜的共轴。In the deflection type radial shear interference system, the quality of the standard parallel light source has an important influence on the accuracy of subsequent measurement and detection. In the embodiment, a collimating beam expander system S2 is composed of a pair of concave lenses and a pair of split objective lenses, and finally a parallel beam of about Φ70 mm can be obtained. The coaxiality of the biconcave lens and the double separation objective lens can be adjusted through a precise five-dimensional adjustment mechanism.

实施例中的高剪切比大口径望远镜系统S7采用大口径伽利略扩束缩束系统。其中，大端镜组的有效通光口径

，小端镜组的有效通光口径

，扩束缩束比

。整个镜组的理论波前畸变小于

，这将可以有效地减轻边缘衍射效应的影响，提高获得干涉图的质量。The high-shear ratio large-aperture telescope system S7 in the embodiment adopts a large-aperture Galilean beam expander and contraction system. Among them, the effective light aperture of the large end lens group

, the effective aperture of the small end lens group

, beam expansion and contraction ratio

. The theoretical wavefront distortion of the whole mirror group is less than

, which will effectively reduce the impact of the edge diffraction effect and improve the quality of the obtained interferogram.

实施例中调节光路使得各部分光学系统等高同轴，且使得经过分光镜S5的两束光互成90°夹角，调节反射镜S6和反射镜S8在水平方向上的倾角使得经过成像透镜S9的两束光的光斑在探测器S10上重合，加入高剪切比大口径望远镜系统S7后调节其位置和倾角使得探测器S10上的缩束光斑与扩束光斑同心，且产生干涉条纹。在此基础上，逐步调节反射镜S6和反射镜S8在竖直方向上的倾角，使得探测器S10上的缩束光斑移出扩束光斑目标物阴影处并产生干涉。图4是探测器S10前缩束光斑和扩束光斑以及其中目标物阴影的位置示意图与干涉图。可以发现此时的缩束光斑已经移出了扩束光斑中目标物的阴影区，同时也形成了干涉条纹。图5是经截取后的探测器S10接收到的干涉条纹。利用该干涉条纹可以对目标物周围待检测区域的加以测量。In the embodiment, the optical path is adjusted so that each part of the optical system is equal and coaxial, and the two beams of light passing through the beam splitter S5 form an angle of 90° with each other, and the inclination angles of the mirror S6 and the mirror S8 in the horizontal direction are adjusted so that they pass through the imaging lens The spots of the two beams of S9 overlap on the detector S10, and after adding the high-shear ratio large-aperture telescope system S7, its position and inclination are adjusted so that the reduced beam spot and the expanded beam spot on the detector S10 are concentric, and interference fringes are generated. On this basis, the inclination angles of the mirrors S6 and S8 in the vertical direction are gradually adjusted, so that the narrowed beam spot on the detector S10 moves out of the shadow of the expanded beam spot target and produces interference. FIG. 4 is a schematic diagram and an interference diagram of the positions of the reduced beam spot and the expanded beam spot and the shadow of the target object in front of the detector S10. It can be found that the reduced beam spot at this time has moved out of the shadow area of the target in the expanded beam spot, and interference fringes have also been formed. FIG. 5 is the intercepted interference fringes received by the detector S10. The interference fringe can be used to measure the area to be detected around the target object.

对于干涉条纹的位相解调，传统的移相技术在精度和噪声抑制上有很大的优势，但由于需要采集多幅干涉图，不符合瞬态检测的要求；而傅里叶变换方法在有遮挡的情况下又不便于使用。鉴于多种位相解调技术无法应用于中心遮挡情况下的干涉条纹位相解调，实施例中采用了二维正则化条纹位相解调技术对得到的干涉图进行了处理。图6 是采用干涉位相解调方法后得到的去除目标物遮挡部分的波前位相分布图。For the phase demodulation of interference fringes, the traditional phase shifting technology has great advantages in accuracy and noise suppression, but it does not meet the requirements of transient detection due to the need to collect multiple interferograms; It is not convenient to use in the case of occlusion. In view of the fact that various phase demodulation techniques cannot be applied to the phase demodulation of the interference fringe in the case of central occlusion, the two-dimensional regularized fringe phase demodulation technology is used in the embodiment to process the obtained interferogram. Figure 6 is the phase distribution diagram of the wavefront obtained by removing the occlusion part of the target object after using the interferometric phase demodulation method.

Claims (2)

1. the heavy caliber deviation type radial shear interference pick-up unit under the central shielding situation is characterized in that comprising that laser instrument (S1), collimating and beam expanding system (S2), object (S3), zone to be measured (S4), spectroscope (S5), first catoptron (S6), high shear are than heavy caliber telescopic system (S7), second catoptron (S8), imaging len (S9) and detector (S10); Wherein, Object (S3) places center, zone to be measured (S4), and laser instrument (S1), collimating and beam expanding system (S2), object (S3), spectroscope (S5), first catoptron (S6), high shear are than heavy caliber telescopic system (S7), second catoptron (S8), spectroscope (S5), imaging len (S9) and detector (S10) series arrangement in article one light path; Laser instrument (S1), collimating and beam expanding system (S2), object (S3), spectroscope (S5), second catoptron (S8), high shear are than heavy caliber telescopic system (S7), first catoptron (S6), spectroscope (S5), imaging len (S9) and detector (S10) series arrangement in the second light path; First catoptron (S6) all becomes angle

with second catoptron (S8) with vertical direction;

is

, makes the process high shear depart from former optical axis than the Shu Guang that contracts of heavy caliber telescopic system (S7) with expansion Shu Guang.

2. the heavy caliber deviation type radial shear interference detection method under the use central shielding situation of installing according to claim 1 is characterized in that comprising the steps:

(1) it is high more coaxial than heavy caliber telescopic system (S7), second catoptron (S8), imaging len (S9), detector (S10) etc. to regulate laser instrument (S1), collimating and beam expanding system (S2), spectroscope (S5), first catoptron (S6), high shear, and adjusting collimating and beam expanding system (S2) makes the heavy caliber parallel light emergence;

(2) angle of adjusting spectroscope (S5) makes the transmitted light and the reflected light of process spectroscope (S5) be mutually 90 ° of angles, and is radiated at respectively on first catoptron (S6) and second catoptron (S8);

(3) regulate first catoptron (S6) and second catoptron (S8) angle in the horizontal direction and the inclination angle on the vertical direction, make article one light path and second light path pass through the hot spot coincidence on detector (S10) behind the imaging len (S9);

(3) between first catoptron (S6) and second catoptron (S8), add high shear than heavy caliber telescopic system (S7), position and the inclination angle of regulating this telescopic system make that the bundle hot spot that contracts on the detector (S10) is concentric with expansion bundle hot spot, and produce interference fringe;

(4) regulate the inclination angle of first catoptron (S6) and second catoptron (S8) in the vertical direction, make that the bundle hot spot that contracts on the detector (S10) shifts out the object shaded that expands the bundle hot spot and produces interference;

(5) gather the interferogram that receives on the detector (S10), the part light wave that expands Shu Boqian participation interference is approximately plane wave, interferogram is carried out phase place unpack, obtain the phase data of interferogram.

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