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Displacement measurements and position sensing have been playing an important role in many fields such as fabrication, biophysics, and autocontrol. Interferome- try, laser triangulation, optical fiber sensing and moiré technique are common optical measuring methods[1-3]. Among these methods, moiré technique holds the most interest due to its high accuracy, large range, low cost, and other advantages. When a long working distance is required, or when space is not at a premium, a moiré sys- t… 相似文献
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基于方解石晶体的光学特性和传统Wollaston棱镜的结构特点,设计了一种新型Wollaston式多光束分束棱镜。棱镜的两块晶体的光轴不再是垂直的,而是呈现一定的角度。通过结合玻璃棱镜,可以实现三束或四束光束平行光束的出射。以晶体光轴夹角为45°角为例,对该棱镜进行了讨论研究。研究得出:当一束自然单色光入射时,当入射光束的光斑大小大于两平行光束之间的距离时,可以实现两束相互垂直的偏振光和一束自然光出射,当光斑大小小于棱镜中两平行光束之间的距离时,能够产生四束分开程度可调并且平行出射的偏振光。该棱镜能为不同的应用环境提供可调节的偏振出射光束,从而节约成本。 相似文献
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提高光学相干层析成像纵向分辨率的方法 总被引:2,自引:1,他引:1
光学相干层析成像技术是一种新型的成像技术,能实现对活体生物组织(透明和不透明)非接触、无伤害、高分辨率的体内断面成像。光学相干层析成像利用相干门技术,其纵向分辨率取决于光源的相干长度,要进一步提高它的纵向分辨率必须从光源入手,本文对采用不同光源提高光学相干层析成像纵向分辨率的方法进行了详细的讨论。 相似文献
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A double sinusoidal phase modulating (SPM) laser diode interferometer for thickness measurements of a transparent plate is presented. A carrier signal is given to the interference signal by using a piezoelectric transducer, and the SPM interferometry is applied to measure the thickness of a transparent plate. By combining the double-modulation technique with the Bessel function ratio method, the measurement error originating from light intensity fluctuations caused by the modulation current can be decreased greatly.The thicknesses of a glass parallel plate and a quartz glass are measured in real time, and the corresponding experimental results are also given. 相似文献
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A double sinusoidal phase modulating (SPM) laser diode interferometer for thickness measurements of a transparent plate is presented. A carrier signal is given to the interference signal by using a piezoelectric transducer, and the SPM interferometry is applied to measure the thickness of a transparent plate. By combining the double-modulation technique with the Bessel function ratio method, the measurement error originating from Sight intensity fluctuations caused by the modulation current can be decreased greatly. The thicknesses of a glass parallel plate and a quartz glass are measured in real time, and the corresponding experimental results are also given. 相似文献
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Position sensor based on slit imaging 总被引:2,自引:0,他引:2
A position sensor based on slit imaging is proposed and its measurement principle is described. An imaging slit is illuminated by a collimated laser beam with square-wave modulation and imaged on a detection double slit through a 4f system. A magnified image of the detection double slit is formed on a bi-cell detector. The position of the imaging slit is obtained by detecting light intensity on two parts of the hi-cell detector. In experiments, the feasibility of the sensor was verified. The repeatability was less than 40 nm. 相似文献
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双沃拉斯顿棱镜光强分束比精确分析 总被引:1,自引:0,他引:1
利用折射定律,介质膜两侧折射率不同时多光束干涉理论和菲涅耳公式,精确推导了双沃拉斯顿棱镜的光强分束比的具体表达式。以公式为基础,通过Matlab软件数值模拟作图分析光强分束比随入射角、入射波长和结构角的变化关系曲线。结果表明:在棱镜为介质胶合型时,光强分束比随入射角和入射波长的变化很小,光强分束比基本为1;棱镜为空气胶合型时,光强分束比随入射角,结构角和波长的变化很大。两种情况下,光强分束比随各参量的变化基本呈周期性变化。 相似文献
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An accurate phase shift extraction method for generalized phase-shifting interferometry is suggested. Based on the nearly random phase distribution of the diffraction field of the object, a singular formula is derived to calculate the unknown phase shift without the requirements of an iteration process or the selection of the correct value from two or more possible phase shift solutions as needed before. This method can be used in the cases of two or more frames with both smooth and diffusing object surfaces. Computer simulations and optical experiments have satisfactorily verified the efficiency and accuracy of this method. 相似文献