共查询到18条相似文献,搜索用时 127 毫秒
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四区域法消除偏振棱镜缺陷对波片相位延迟测量的影响 总被引:1,自引:0,他引:1
在起偏器-待测波片-检偏器系统基础卜提出一种四区域测量波片相位延迟量的方法.调整待测波片和检偏器的方位角,获得相应的四组光强值,通过线性运算得到待测波片的相位延迟量,完全消除了起偏器和检偏器不完全消光带来的误差.由于测量系统中不存在标准波片或其他相位调制元件,允许测量波长仅受偏振棱镜和探测器的限制,因此四区域法可适用于很大波长范围内的波片测量.以λ/4波片为例,理论分析了测量系统利用四区域测量法后的仪器误差为σφ≤士3.49065×10-3rad(约0.2°),精度比原算法提高约1个数量级.实验验证了四区域法能有效提高系统精度. 相似文献
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基于偏光干涉理论,提出一种宽光谱范围内测量波片相位延迟量和厚度的方法。利用矩阵光学方法分析了光谱透射率曲线与中值透射率直线交点波长之间的关系,给出待测波片的相位延迟量、波片厚度等多个物理量的计算公式并进行了误差分析。误差分析表明本方法相位延迟量测量最大误差为3.38°,厚度测量最大误差为0.66μm。实验上利用分光光度计验证了本方法的有效性。本方法能够实现波片多物理量的同时测量,且调节过程对于起偏器、检偏器透光轴方向及待测波片快轴方向无严苛要求,测量过程对波片也无损伤和污染,在波片加工、使用前质量评估等方面都具有一定的应用价值。 相似文献
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精确确定光路中四分之一波片光轴方位的新方法 总被引:1,自引:1,他引:0
为了准确安装四分之一波片,介绍了一种精确确定光路中四分之一波片光轴方位的新方法,并利用米勒矩阵理论分析了影响测量结果的误差因素.测试方法所用的主要理论有米勒矩阵理论、傅里叶分析方法和最小二乘法.该方法利用最小二乘法得到了最优傅里叶系数,利用消光比测试原理实现了检偏棱镜的精确安装,利用反馈环控制系统对步进电机的步进角进行了控制.误差分析表明该方法的测量误差与四分之一波片光轴方位角本身的大小有关.实验结果表明该方法的标准不确定度为0.03. 相似文献
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波片相位延迟量精密测量新方法 总被引:18,自引:7,他引:11
利用旋转波片的偏振干涉技术,结合机械-光学旋光调制器对光相位的调制,通过判断方波信号的有无,可精密地确定被测定片相位延迟的数值,机械-光学旋光调制器的使用,大大简化被测样品和测试装置中四分之一波片光轴方位的调整,也显著地提高了装置测量的灵敏度和波长测量范围,对环境不作特殊控制,依据本方法建立的测试装置的相对测量误差可小于千分之五。 相似文献
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The Fourier transform method, widely applied in photomechanics for the automated analysis of interferometric fringe patterns, has been recently extended to the photoelastic isochromatic fringe patterns analysis. Unfortunately, its use in photoelasticity involves some limitations that have not been completely highlighted in literature. This work deals with the influence of the quarter-wave plate tolerance on the evaluation of the retardation. Both theoretical and experimental analyses have shown that the quarter-wave plate error does not affect the retardation only if the principal stress directions in the model and in the carrier are aligned. In general, instead, the tolerance of the quarter-wave plates leads to an amplification of the retardation error due to the influence of the isoclinics with a subsequent restriction of the field in which the method can be applied. For instance, using common quarter-wave plates and tolerating a maximum retardation error of about 0.03 fringe order, than the Fourier transform method cannot be applied as a full-field technique but only in the model zones in which the misalignment between the principal stresses in the model and in the carrier is less than 15°. 相似文献
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A method for measuring retardation of a quarter-wave plate based on normalized secondary harmonic component is proposed, and the measuring principle is analyzed. The optical measuring system is composed of a laser, a polarizer, a phase modulator, the quarter-wave plate to be measured, an analyzer and a detector. The azimuths of the transmission axes of the polarizer and the analyzer with respect to the modulating axis of the phase modulator are +45°, 0°, respectively. The retardation of the quarter-wave plate is calculated precisely using the normalized secondary harmonic components prior to and after 22.5° rotation of the quarter-wave plate. In this method, the major axis position of the quarter-wave plate is not required to be known in advance, and the measured retardation is independent of the intensity fluctuation of the light source. The feasibility of the method is verified by the experiments. 相似文献
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A method for rapid measuring retardation of a quarter-wave plate based on simultaneous phase shifting technique is presented. The simultaneous phase shifting function is realized by an orthogonal grating, a diaphragm, an analyzer array, and a 4-quadrant detector. The intensities of the light beams from the four analyzers with different azimuths are measured simultaneously. The retardation of the quarter-wave plate is obtained through the four light intensity values. In this method, the major axis position of the quarter-wave plate need not be determined in advance. In addition, the measured result is free of the intensity fluctuation of light source. The feasibility of the method is verified by the experiments. 相似文献
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为了避免机载光电吊舱中共口径光学系统内部由于道威棱镜旋转引起的激光照射脉冲偏振态的变化,利用琼斯矩阵对道威棱镜的偏振特性与四分之一波片、半波片补偿道威棱镜旋转引起的激光脉冲偏振态变化进行了理论分析和实验验证。结果表明:线偏振的激光脉冲通过旋转一定角度的道威棱镜时,激光脉冲偏振态变为椭圆偏振,偏振态发生变化;而激光脉冲首先通过旋转一定角度的四分之一波片与半波片时,可使通过道威棱镜系统的激光脉冲偏振态保持不变,且两波片旋转角度与道威棱镜旋转角度之间存在一种非线性关系。采用偏振补偿方法可有效避免机载共口径光学系统中道威棱镜引起的激光脉冲偏振态变化,提高激光脉冲能量利用率,降低激光脉冲后向散射抑制难度。 相似文献
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It has long been recognized 1,2,3,4,5 in measuring relative intensities and depolarization ratios of Raman lines that prism and grating spectrometers have different transmittances for light polarized parallel (T∥) and perpendicular (T⊥) to the slit. Several methods have been used to give equal instrument response to parallel and perpendicular polarization. Stitt and Yost3 used a Nicol prism parallel to the high-transmittance direction of the spectrometer, combined with a rotatable mica half-wave plate to transmit either vector to the Nicol prism. This method has the advantage of having a higher spectrometer transmittance, but the mica plate gives exact half-wave retardation at only a single wavelength. A mica quarter-wave plate 4,5 averages the transmittances of the spectrometer for the two polarization directions, but is also wavelength dependent. Virtually achromatic circular polarizers have been designed and constructed 6,7, but these devices are too bulky and expensive for the clear apertures needed for fast spectrometers. 相似文献
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A real-time measurement method for the retardation of an eighth-wave plate is proposed. The collimated laser beam is split using a Glan Taylor polarizer with two side escape windows. The reflected sub-beam is detected using a detector, whereas the transmitted sub-beam passes through the quarter-wave plate and the eighth-wave plate of interest. Then, it is reflected by the mirror and passes reversely through the eighth-and quarter-wave plates. Finally, it is analyzed using the Glan Taylor polarizer and detected using another detector. With two detection signals, the retardation is resolved and found to be independent of the fast-axis direction, initial intensity, and circuit parameters. In the experiment, a crystal quartz sample is measured at different fast-axis angles. The standard deviation of the retardation is 0.9 o . The usefulness of the method is verified. 相似文献
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Zheng Ping Wang Qing Bo Li Qiao Tan Zong Jun Huang Jin Hui Shi 《Optics & Laser Technology》2004,36(4):285-290
A novel and simple method used for measurement of retardance of a quarter-wave plate employing two polaroids and a right-angle prism is reported. The theoretical analysis of the principle is given taking the Jones matrix as a mathematical tool. The uncertainty of the method is theoretically analyzed. An application example is also given. The measured result of the example is verified with a test. The main advantage of this method is that it can completely determine the retardance value, which overcomes the shortcomings of the existing methods reported before for determining only the multi-value function values, such as cosine or tangent value of the retardance. In addition, this method is also accurate, easy to operate and can also be used for the retardance measurement of other retardation plates. 相似文献
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Zheng Ping Wang Qing Bo Li Qiao Tan Zong Jun Huang Jin Hui Shi 《Optics and Lasers in Engineering》2005,43(11):1448
A novel method used for the enhancement of the accuracy of the retardance measurement of a quarter-wave plate employing two polaroids and a prism is reported under the condition of knowing the direction of the fast-axis of the plate. The theoretical analysis of the principle and the uncertainty formula are given. An application example is also demonstrated. The measured result of the example is verified with an experiment. The main advantages of this method include the accuracy enhancement, simple measuring setup and easy operation. 相似文献