像元阵列同步移相共光路干涉相位动态测量理论及方法

The popular phase measuring methods based on optical interference principle are not suitable for the engineering condition because of not resisting well the effect from external vibration, air turbulence, temperature variation and other environmental factors. Employing the idea of simultaneous phase shifting and common-path interference to realize the absolute common path and single-shot exposure simultaneous measurement, is the optimal technical scheme in improving environmental adaptability and application universality of the interferometric phase measuring technology. However, the presented simultaneous phase-shifting methods hold many problems such as intensity nonuniform of splitting beams, different pathway being easily affected from air turbulence, large optical structure, difficulty in fabricating key components, and it is difficult to introduce phase modulation in the common-path structure as well. The project proposes the pixilated array simultaneous phase-shifting method with no requirement of splitting light, simple structure and easy to realization. Furthermore, through incorporating with high-performance common-path point-diffraction structure, it will bring out a high-accuracy dynamic measuring technology applying to phase detection in engineering environment. The theory and key techniques including pixilated array simultaneous phase-shifting mechanism, common-path interferometric setup, phase dynamic measurement scheme and realization methods of technical principles, will be studied profoundly. Consequently, this work can provide the relative theoretical and experimental foundations for building a phase dynamic measuring technology that holds some valuable characteristics such as anti-disturb, super compact, low cost and flexible application, and for next producibility of this technology.

常用的光学干涉相位测量技术由于不能克服环境振动、气流扰动、温度变化等因素的影响而很难在工程现场使用。采用同步移相及共光路干涉的思想，实现完全共光路、单次曝光实时测量，是用来改善干涉相位测量技术的环境适应性与应用普适性的最佳技术方案。然而目前同步移相技术存在诸如分光不均匀、不同通道易受空气扰动的影响、光学结构庞大、关键元件制造难度大、以及共路干涉结构难以引入相位调制等问题。本项目提出一种无需分光、结构简单、易于实现的像元阵列同步移相方法；进一步结合高性能的共光路点衍射结构，以产生一种适用于工程现场相位测量的高精度动态测量技术。通过对像元阵列同步移相机理、共光路干涉结构、相位动态测量方案、技术理论的实现方法进行深入研究，从而为建立一种抗干扰、超紧凑、低成本、应用灵活的相位动态测量技术以及后续该技术的产品化提供理论与实验基础。

激光移相干涉是一种常见的高精度面形测量技术，为了克服环境干扰的影响，经常采用同步移相手段来实现单次拍摄、实时测量。然而目前同步移相技术存在光学结构庞大或者复杂、应用普适性欠佳等的问题。本项目提出基于純相位液晶空间光调制器（LCSLM）的像元阵列同步移相方法，利用一帧干涉图便可根据移相算法复原被测相位,可用于（非）共光路偏振干涉系统，结构紧凑、应用灵活。项目主要完成了像元阵列同步移相干涉及高分辨率复原算法的理论研究及数值仿真，高分辨率高灰阶LCSLM特性测试与性能评价，共光路点衍射干涉仪结构设计与条纹对比度分析，像元阵列同步移相干涉实验研究。在实验室阶段验证了像元阵列同步移相技术方案的有效性，证实了循环复原算法可以有效提高结果的空间分辨率。研究结果表明使用純相位LCSLM并当器件的相位调制保持稳定的情况下，本方法能够应用于实际干涉仪系统。在针对LCSLM的测试方法的研究中，提出的三方面技术方法（例如基于渥拉斯顿棱镜的共光路载波干涉技术精确测量LCSLM整体相位调制特性，基于傅里叶变换法结合载波干涉条纹的局部相位调制特性测量，十字形Hanning滤波器结合约45度载波干涉条纹测量台阶高频波面），具有明显的技术优势，在精密测量领域将具有重要实用价值。