共查询到13条相似文献,搜索用时 62 毫秒
1.
2.
3.
4.
5.
为解决棱镜等效展开为玻璃平板后因腔长固定导致的移相困难问题,提出一种变倾角移相测量反射棱镜光学平行差的方法。通过改变光束在反射棱镜入射端面上的倾角在干涉图中引入移相量,实现干涉图中的相位提取。采用最小二乘法拟合相位计算反射棱镜的光学平行差。在实验中,测试了一块弦长为56.5mm的等腰直角棱镜,得到直角偏差Δ_(90°)为-2.1435″、锐角偏差δ_(45°)为-4.6216″、直角边对应棱差γ_C为0.3554″,而Zygo GPI干涉仪仅可得到棱镜直角偏差,与本文方法的测量值偏差在0.15″以内。所提方法移相光路设计简便,并可实现小尺寸反射棱镜的测量。 相似文献
6.
论述了用激光干涉仪测量石英玻璃光学均匀性时测量范围扩展的问题。通过理论研究和实际测量,完成了用180mm孔径干涉仪测量300mm孔径石英玻璃光学均匀性这一目标,为实现用300mm孔径干涉仪测量直径500mm石英玻璃的光学均匀性测量问题奠定了理论与实践的基础。实验通过建立光学均匀性测量范围扩展的数学模型,采用最小二乘法误差消除方法,每步波面分别计算,最后四步合成。创新性地设计了移动测量载物调整装置,实现了高精度多维调整。采用8个子孔径就3块圆形玻璃进行了测试,就拼接测量结果与直接全口径测量结果进行了对标,其拼接波面的均匀性绝对误差平均值分别为0.13×10-5、0.14×10-5、0.03×10-6。 相似文献
7.
积分球辐射光源照度均匀性研究 总被引:2,自引:1,他引:2
针对CCD等焦面阵列光电器件常被置于积分球辐射光源出口平面进行测试的误区,研究了积分球辐射光源照度分布的均匀性,得到了合理使用积分球光源测试光电器件的依据。基于数值解析方法和蒙特卡罗方法,建立了理想积分球辐射光源照度均匀性数学模型和非理想积分球辐射光源照度均匀性仿真模型,分析了与积分球光源出口不同距离处光电器件受光面上照度分布情况,并实验测试了两套积分球辐射光源照度分布情况,得到了与积分球辐射光源不同距离处光电器件受光面上照度均匀性分布规律。研究表明:当光电器件受光面直径小于积分球光源出口直径一半、光电器件和积分球出口之间的距离与积分球出口直径的比值在3至5之间时,可在光电器件受光面上获得均匀性优于99%的照度场。 相似文献
8.
9.
10.
11.
The application of the technique of synthesis of optical coherence function for detection in scattering media is investigated. By modulating the optical frequency, the technique synthesizes the coherence function into a delta-function-like peak at an arbitrary location, and thus can select interferometrically the information at that location. The location is adjustable by the modulation parameter or additional phase modulation. A multi-section super-structure grating distributed Bragg reflector laser diode (SSG-DBR-LD) of THz-order tunable range is employed to enhance the spatial resolution for suppressing the multiple scattering from locations other than that detected. In a preliminary experimental demonstration, a reflectometry of 550 μm spatial resolution was achieved and was used to detect scattering media. 相似文献
12.
We demonstrate a novel low coherence Michelson interferometer which can provide simultaneous measurement of the refractive index and thickness of transparent plates used as a measured object. Unlike the existing low coherence interferometers reported so far, either an object or a focusing lens aligned on the signal arm is scanned repeatedly by a precise translation stage in synchronization with movement of a reflection mirror on the reference arm. The so-called object or lens scanning method gives us two measured quantities a movement distance of the stage between two light focusing states on the front and rear planes of an object and the corresponding optical path difference. These two measured quantities, result in desirable values of the index and thickness of the object with a short calculation. The measurement accuracy of ≤0.1% is expected for a thickness of more than 1 mm. In the experiment using the object scanning method, the accuracy of 0.3% or less was successfully attained for nearly 1-mm thick plates of fused quartz, sapphire, LiTaO3 and slide glass. 相似文献
13.
Low coherence interferometry can provide simultaneous measurement of refractive index n and thickness t of a transparent plate, as reported recently by some research groups. Precise measurement of n and t is impossible unless chromatic dispersion of index is taken into account. We then proposed and demonstrated a unique technique for simultaneous measurement of phase index np, group index ng and thickness t using a special sample holder. This paper describes a novel technique for simultaneous measurement of np, ng and t using an approximate expression of the chromatic dispersion in terms of np. The approximate expression of chromatic dispersion does not require use of the special sample holder, and np, ng and t are determined from two measurable quantities with an accuracy of 0.3% or less, for the sample thickness was around 1 mm. In addition, it is possible to shorten the measurement time compared with the above method. 相似文献