激光外差干涉仪光电信号处理方法及特点

叙述和分析了外差激光干涉光电信号处理主其特点，指出了它们各自的应用范围，同时介绍了一处新型的光电信号处理方法，它不仅使外差干涉仪用于动态测量，而且可以同时实现高分辩率测量 。     

InfraRed Astronomy Satellite Swarm Interferometry (IRASSI): Overview and study results

The far-infrared (FIR) regime is one of the few wavelength ranges where no astronomical data with sub-arcsecond spatial resolution exist yet. Neither of the medium-term satellite projects like SPICA, Millimetron or OST will resolve this malady. For many research areas, however, information at high spatial and spectral resolution in the FIR, taken from atomic fine-structure lines, from highly excited carbon monoxide (CO) and especially from water lines would open the door for transformative science. These demands call for interferometric concepts. We present here first results of our feasibility study IRASSI (Infrared Astronomy Satellite Swarm Interferometry) for an FIR space interferometer. Extending on the principal concept of the previous study ESPRIT, it features heterodyne interferometry within a swarm of five satellite elements. The satellites can drift in and out within a range of several hundred meters, thereby achieving spatial resolutions of <0.1 arcsec over the whole wavelength range of 1–6 THz. Precise knowledge on the baselines will be ensured by metrology methods employing laser-based optical frequency combs, for which preliminary ground-based tests have been designed by members of our study team. We first give a motivation on how the science requirements translate into operational and design parameters for IRASSI. Our consortium has put much emphasis on the navigational aspects of such a free-flying swarm of satellites operating in relatively close vicinity. We hence present work on the formation geometry, the relative dynamics of the swarm, and aspects of our investigation towards attitude estimation. Furthermore, we discuss issues regarding the real-time capability of the autonomous relative positioning system, which is an important aspect for IRASSI where, due to the large raw data rates expected, the interferometric correlation has to be done onboard, in quasi-real-time. We also address questions regarding the spacecraft architecture and how a first thermomechanical model is used to study the effect of thermal perturbations on the spacecraft. This will have implications for the necessary internal calibration of the local tie between the laser metrology and the phase centres of the science signals and will ultimately affect the accuracy of the baseline estimations.     

外差干涉测量系统的标定

对纳米级测量系统进行标定是一个难题。结合某一外差干涉测量系统，提出了一个对测量系统的分辨力、输入输出特性进行标定的简单易行的方法。     

光纤外差干涉位移传感器

非接触式光纤外差干涉位移传感器是将半导体激光器线性调频技术和光纤传感技术相结合制成的1种新型外差干涉仪。它的位移测量范围可达26mm，分辨率为0．02μm；对不同材料、不同粗糙度的对象面，有着几乎相同的测量灵敏度和测量精度；探头和对象面无需严格垂直。     

激光外差干涉信号处理技术的研究

介绍了两种激光外差干涉信号的处理方法锁相频率解调法及组合频率解调法。此方法适用于需要实时反馈控制以及定位曝光等场合。用此方法,可以使干涉仪的测量分辨力分别达到３ｎｍ和０．５ｎｍ,干涉仪测量棱镜的允许运动速度达到３ｍｍ／ｓ。     

调频光外差光纤位移传感器响应速度的研究

对调频光外差光纤位移传感器的动态响应速度进行了理论分析和实验论证。实验结果表明：调频光外差光纤位移传感器响应速度的提高，可通过增大调制频率和利用拍频信号的高次谐波成分来实现。