共光路外差干涉仪中激光束角漂移的影响

共光路外差干涉仪中激光束角漂移的影响＊李鹏生于瀛洁张琢于英满（哈尔滨工业大学哈尔滨１５０００１）０引言双频激光共光路外差干涉仪测量表面微细形貌原理如图１所示［１］,光路１和光路２的干涉信号的光强由光电元件接收。通过分析计算［２］,可得如下关系式：１．...     

外差干涉仪光路调节方法及对拍频的理解

外差激光干涉仪由于测量精度高,环境适应能力强和实时动态高速测量等特点而广泛应用于机床误差的实时监测中。外差激光干涉仪中,使用平面镜作为转向装置时,接收器上的两束光有可能只是相交而不是重合,这给光路的调节增加了很大的难度。针对这一问题,提出一种辅助光路调节方法,先将光路切换到单频干涉仪,调好光路,再切换到外差干涉仪,利用单频干涉条纹的直观性能可看出外差干涉仪光路调节的好坏。理论分析和实验结果表明,提出的调节方案具有可行性,效果良好,同时通过从单频切换到双频能更深入地理解拍频。     

双频激光干涉仪在机床坐标测量中光路的调整方法

本文介绍使用双频激光干涉仪测量机床定位坐标误差的三角调整方法,和用块规架代替磁力表架及采用五角棱镜等减小测量误差的方法。     

适用于工业现场的小型化双波长激光外差干涉仪

适用于工业现场的小型化双波长激光外差干涉仪李彬，梁晋文（东南大学机械系南京２１００１８）（清华大学精仪系北京１０００８４）０引言多波长激光干涉测量利用合成波长概念，可以在降低或不降低测量灵敏度的前提下，延长干涉测量的非多值区间（ｕｎａｍｂｉｇｕｏｕｓ...     

超精密外差利特罗式光栅干涉仪位移测量系统

开展了扫描干涉光刻机工作台超精密位移测量的实验研究,以提高扫描干涉光刻机的环境鲁棒性。针对扫描干涉光刻机工作台位移测量精度,提出了新型高环境鲁棒性外差利特罗式光栅干涉仪测量系统。介绍了系统测量原理,设计了测量系统,提出了基于Elden公式的系统死程误差建模方法。设计制造了尺寸仅为48mm×48mm×18mm的光栅干涉仪。基于误差模型计算了死程误差,计算结果表明:对于1.52mm死程的光栅干涉仪,宽松的环境波动指标(温度波动为0.01℃、压力梯度为±7.5Pa、相对湿度波动为1.5%、CO2含量波动为±50×10-6)仅引起±0.05nm的死程误差。最后,设计了基于商用双频激光平面镜干涉仪的测量比对系统,开展了光栅干涉仪原理验证实验和测并量稳定性实验。原理验证实验表明:光栅干涉仪原理正确且系统分辨率达0.41nm。测量稳定性实验表明:常规实验室环境下,环境波动引起的死程误差为7.59nm(3σ)@0.9Hz1~10Hz,优于同等环境条件下平面镜干涉仪的31.11nm(3σ)@0.9Hz1~10Hz。实验结果显示系统具有很高的环境鲁棒性。     

简化光路的激光干涉仪及其应用

文中论述了简化光路激光干涉仪的原理,并对该仪器的测试精度和在机械工程中的应用进行了详尽分析。     

声光外差干涉精密动态角度测量系统

本文提出了一种用于精密角度测量的新型干涉仪，使用普通氦－氖激光器，采用声光调制，光外差干涉，电信号混频、比相技术，可得到较高的测量分辨率，干涉仪结构简单，调整方便。     

分光镜对外差激光干涉仪非线性的影响

外差干涉仪的非线性误差不仅由激光源的椭圆偏振态或者非正交线偏振态引起,也由非理想的光学器件引起,其中分光镜是一个重要的误差源。除了通常熟知的偏振漏光,还分析偏振分光镜中可能存在的另一个误差,即偏振分光的正交性,介绍这种误差和其他各种原因(包括激光源的椭圆偏振态或者非正交线偏振态)对外差干涉仪非线性误差的影响,给出检测和区分两类不同频率混叠误差的方法。通过试验证实,偏振分光镜的漏光误差对外差干涉仪非线性的影响通常是可以被忽略不计的。试验研究还发现,与传统的理论假设相反,非偏振分光镜比偏振分光镜对外差干涉仪的非线性误差有着更严重的影响。     

激光外差干涉中声光器件的非均匀声场特性

针对声光晶体内部的声波反射使晶体内声场分布不均匀,影响衍射效率和衍射光场分布,降低激光外差干涉效率的现象,以不改变声光设备为前提提出了光切趾方法.以TeO2晶体为基底,理论分析声光器件的声场分布、体光栅衬度及其对衍射光效率的影响.提出非均匀光栅衬度模型,并利用光切趾法控制空间声场非均匀分布.通过理论仿真结合实验测量,证...     

Image formation in scanned heterodyne microscope systems

Several new scanning microscopic techniques have recently been developed which rely on modulation of the optical beam to enhance the imaging performance. These systems have the common feature that the image is formed by detection or demodulation of an a.c. signal. Techniques have been developed which are sensitive to both intensity and phase information in the sample. We refer to such microscopes as heterodyne imaging systems (and by analogy single-frequency microscopes, operating at d.c. only, are referred to as homodyne) although as we will point out this term is only strictly applicable to the interferometric-based methods. Although the theory for the conventional homodyne scanning optical microscope is well developed there has been no systematic study of heterodyne microscopic techniques, which is the purpose of this paper. Several techniques are discussed and compared and the different ways of extracting amplitude and phase information are considered in detail with reference to experimental systems which have been demonstrated to have good imaging performance.     

Improvement and validity of shock measurements using heterodyne laser interferometer

The improvement and validity of shock measurements using only the laser head (heterodyne laser interferometer) of a commercial laser Doppler vibrometer was investigated by comparing acceleration waveforms measured by a homodyne laser interferometer with those measured by a heterodyne laser interferometer. The acceleration waveforms were generated from the displacement waveforms obtained with a reference quadrature homodyne laser interferometer by applying a numeric differentiation process twice. The differences between the two acceleration waveforms were found to be small with the measurement uncertainty in case of high acceleration level. In a further investigation, the accuracy of the shock measurements taken by the homodyne and heterodyne laser interferometers were compared in computational simulation. The results indicated that the accuracy of the heterodyne laser interferometer was superior to that of the homodyne laser interferometer.     

基于相控外差干涉技术的纳米定位方法的研究

针对工业领域和计量界对定位精度要求的提高,提出了一种基于迈克尔逊干涉仪反向特性的定位控制方法。该方法采用相位锁定控制和外差干涉技术来完成位置测量和控制。在严格控制实验环境条件下,得到了步距值为5 nm的双向步进位移。步距值的不确定度为8×10-9 nm,位移重复性误差小于1 nm。该定位方法的测量尺寸可直接溯源至长度标准,并且采用光电步进相移法可克服压电陶瓷的非线性和蠕变的机械缺陷。该方法在系统环境控制条件下适用于毫米行程位移,可应用于纳米计量和超精密加工等领域。     

A proposed design for a polarization-insensitive optical interferometer system with subnanometric capability

A bidirectional, fringe-counting, two-beam interferometer system is described that can be used for precision length measurement with any laser source that is adequately coherent for the application. The two electrical phase-quadrature signals required for bidirectional electronic counting are obtained from photodetectors at the two interferometer outputs. A thin metal film design for the beam-splitter coating introduces the required phase difference of nearly 90° for both the perpendicular and parallel polarization components. Electronic alignment and control are performed by a system used to continuously monitor the signals produced from the outputs and automatically process these signals to achieve the optimum performance from the interferometer. Interferometers using the technique require a limited amount of optical alignment and all of the electronic adjustments are automatically controlled by the electronic system. These instruments are economical to manufacture and easy to apply in practice, readily achieving subnanometric accuracy in the measurement of changes in optical path.     

一种宽量程光外差干涉信号的处理方法

根据相位测量与整数周期相位计数相结合的思想,给出了一种宽量程光外差干涉信号的处理方法,该方法在保持不降低高的测量分辨率的前提下,扩展测量范围,并可用于动态测量.     

复合式多点测量速度干涉仪光学系统设计

为满足爆炸冲击作用下物质界面的速度测量需求,设计了一种复合式多点测量的速度干涉仪。采用物方和像方双远心光路,将光纤阵列出射的照明激光定点投射到待测物面上,实现了针状滴注式照明,充分利用了照明激光能量,且保证了待测物面在运动过程中具有恒定的照度。成像系统像面采用末端为大芯径的锥形光纤接收信号光,既保证了物面运动过程中信号光与光纤的有效耦合,又保证了信号的单模输出,以便进入单模光纤马赫-曾德干涉仪进行差频干涉。采用具有微小楔角、沿直径方向镀矩形带状45°反射膜的反射镜,将照明光路与成像光路同轴,并校正了成像系统的大量像散。该干涉测量系统在物面运动10mm的行程中,物面滴注式照明照度保持恒定,像面光斑大小没有超出大芯径的光纤芯径。此光学系统能够满足爆炸冲击界面的大行程速度测量需求。     

Depth discrimination in scanned heterodyne microscope systems

The optical transfer function of several scanning microscope systems is derived, using a physically intuitive approach. The technique allows a wide range of systems to be modelled with only minor modifications to the basic formulation. The results are then used to determine the response of various scanning microscopes for objects both in and out of the focal plane. The possibility of performing extended-focus phase imaging in heterodyne microscopes by scanning the sample along the optical axis is also examined. This mode of operation should allow measurements of minute topographical and phase variations on tilted or warped samples with the same lateral resolution as would be obtained when the sample is in focus throughout the entire scan.     

3-D成像新技术——光学外差扫描全息术

介绍了一种新的3-D成像技术—光学外差扫描全息术的基本原理,以及基于光学外差扫描全息术基本原理的环形光栅光学扫描全息术,描述了其与传统的光学外差扫描全息术相比具有的优势。最后,以光学外差扫描全息术在三维空间滤波、遥感和三维混浊液体中成像应用为例,阐述了这一新技术的应用前景。