从反射面检测锥体棱镜直角误差的方法

介绍了一种使用平面干涉仪检测锥体棱镜直角误差的方法。使用这一检测方法时需要制做一个角度为24.4°的夹具,将被测棱镜放置在夹具之上。这个夹具的作用是,可以使来自干涉仪的标准平行光束(测试光束)由反射面折射入棱镜内,并且垂直于被测直角棱线,经被测直角两个面的反射光仍按原光路返回。当出射光束与干涉仪的标准平行光束(参考光束)重合时产生干涉,实现在平面干涉仪上对锥体棱镜直角误差的测量。与传统的测量方法相比较,该方法具有测量准确、计算精度高的特点。适合于对高精度锥体棱镜(α≤3″)直角误差的测量。     

从入射面检测锥体棱镜直角误差的方法

介绍了一种应用激光平面干涉仪从入射面检测锥体棱镜直角误差的方法。棱镜被测角通过一个夹具被预置一个初始角,使射入棱镜内的测试平行光垂直于被测角棱,经被测直角的两个面反射后形成全反射光路,当射出的光与测试平行光重合时产生干涉,实现对锥体棱镜直角误差的测量。介绍了测量、干涉条纹图形分析和直角误差计算的方法,并与传统检测方法进行了比较。结果表明,该方法具有操作简单、测量准确、计算精度高等特点,适合于高精度锥体棱镜(α≤3″)的直角误差测量。     

高精度(Δ90°≤0.5″)长方体的制造技术

高精度(Δ90°≤0.5″)长方体的制造技术主要包括了加工方法和检测方法两个方面,即长方体的前期加工阶段采用立方体(方砖)形式加工,以保证一个直角的精度;后期是采用分离器单块精抛的加工方式,以保证其平行差。加工过程中用Φ150激光平面干涉仪检测和控制面形及平行度,用LY Φ80棱镜干涉仪检测和控制直角精度。这种制造技术可以将长方体的直角精度做到Δ90°≤0 5″。     

信息光学 光学记录、存储与器件

TP333.4 2004053598 光盘基片平整度的相移干涉测量方法=Phase-shifting interferometry to the flatness of a compact disk[刊,中]/苏俊宏(西安工业学院陕西省薄膜技术与光学检测重点实验室,陕西,西安(710032)),陈磊…∥光电工程。—2004,31(1),—29-31 使用工作波长为10.6μm的红外激光平面干涉仪对光盘基片的表面面形进行了移相式干涉法测试,对测试     

迈克耳孙干涉仪中的镜面面形误差研究分析EI北大核心CSCD

从迈克耳孙干涉仪干涉原理出发,分析了圆形镜面抛光面形误差对干涉调制度的影响。由于存在镜面面形误差,干涉调制度不能达到理想情况下的100%,但其干涉调制度不能低于理想情况下的90%。通过分析和讨论,镜面面形误差最好控制在λ/14以内,干涉调制度才可能不低于90%,这样干涉仪才能保持比较满意的性能。同时,使用Zygo干涉仪对5组平面镜的平面度进行了测量,得到了这5组平面镜的峰-峰值和其他一些参数,通过分析测量结果,这5组平面镜的平面度都能达到干涉调制度的要求。通过对迈克耳孙干涉仪中平面镜面形误差的研究,这对于干涉光谱仪的设计、研制和性能的分析都具有一定的指导意义。     

迈克耳孙干涉仪中的镜面面形误差研究分析

从迈克耳孙干涉仪干涉原理出发,分析了圆形镜面抛光面形误差对干涉调制度的影响。由于存在镜面面形误差,干涉调制度不能达到理想情况下的100%,但其干涉调制度不能低于理想情况下的90%。通过分析和讨论,镜面面形误差最好控制在λ/14以内,干涉调制度才可能不低于90%,这样干涉仪才能保持比较满意的性能。同时,使用Zygo干涉仪对5组平面镜的平面度进行了测量,得到了这5组平面镜的峰-峰值和其他一些参数,通过分析测量结果,这5组平面镜的平面度都能达到干涉调制度的要求。通过对迈克耳孙干涉仪中平面镜面形误差的研究,这对于干涉光谱仪的设计、研制和性能的分析都具有一定的指导意义。     

棱镜透镜干涉仪总体设计中的一些考虑

<正> 一、总体参数的确定及总体方案的选择棱镜透镜干涉仪(又称泰曼-格林干涉仪)是棱镜干涉仪和透镜干涉仪的总称,是一种高精度、多功能的光学测试仪器。棱镜干涉仪用于检测具有平面性质的光学零件或光学系统的质量,如平板玻璃、各种棱镜以及望远系统等。透镜干涉仪主要用于测定望远物镜、照相物镜的波象差。棱镜透镜干涉仪采用的是分振幅双光束相干光路,其中测试光路的标准平面波经被检测的光学零件或光学系统后变成了由被检测件质量所决定的变形波面,该波面与参考光路的标准平面波汇合而产生干涉图形,根据干涉图形     

移相式干涉仪在锥体棱镜角度测试中的应用

为了实时、高精度地测试光学零件，对移相式数字波面干涉仪在锥体棱镜角度测试中的应用进行了研究。通过锥体棱镜二面角偏差计算方法得到了二面角偏差和干涉波面之间的关系，分析了干涉波面的形状与锥体棱镜综合误差的关系，编写了锥体棱镜角度和综合误差测试程序，并且在移相式数字波面干涉仪和ZYGO干涉仪上分别对锥体棱镜进行测试，给出了2者的比较测试结果。结果表明，移相式数字波面干涉仪测量锥体棱镜二面角偏差的误差在0.3″范围内，RMS值的测量误差在λ/50内；提出的方法可实现检测过程的自动化。     

干涉测量的误差分析与并联机床的准确度测量

对雷尼绍激光干涉仪的线性测量原理进行了详细探讨,分析了干涉仪在线性测量中的主要影响因素和误差诱因;作出了线性测量的准直误差特性曲线和阿贝误差特性曲面,并利用最小二乘法拟合得到了干涉仪准直测量误差的数学模型和沿u、v方向离散的阿贝误差特性曲线方程;给出了一种建立误差数学模型的方法.采用激光干涉仪检测了并联数控机床直线轴的运动准确度,并提出了一种适合于并联机床直线轴定位准确度测量的干涉测量方法.     

基于插值法波面拟合的球面光学元件检测

为了实现在线自动化检测球面光学镜片的面形偏差,在已有的光学检测系统基础上,对光学检测系统采集的干涉图样进行图像处理和波面拟合算法研究。首先对干涉图样预处理,再根据球面光学镜片大多是圆形孔径,对预处理后的干涉条纹通过最小二乘法拟合出干涉图样的圆边界,确定数据取值边界点的中心和半径值;然后采用Multi-quadric函数插值法拟合出波面的面形轮廓,计算波面的峰谷偏差EPV值及均方根偏差ERMS值;最后用上述方法对Zygo干涉仪采集的干涉图的处理结果与Zygo干涉仪测试结果进行比较分析。结果表明:通过边界处理可有效提高波面拟合精度,采用multi-quadric函数插值法拟合可以理想的还原出波面,且测量误差与国标相比能够控制在0.2的误差范围内,与Zygo干涉仪检测结果相比可以控制在0.03误差范围内,都能够满足球面光学镜片在线检测的精度要求。     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.