基于正交偏振激光回馈的纳米溯源原理和技术研究

The nanometer measurement is the base of the development of nanotechnology. How to realize the tracable nanometer measurement? It is a basic scientific issue unsolved in the international academic circles. It requires not only the nanoscale resolution, but also the tracability to the natural standard and taking into account the environmental disturbance, system complexity and the cost, etc. This proposal presents a new principle of traceable nanomter measurement based on laser nanometer-fringe. It utilizes the high-order feedback effects to produce laser feedback firnge with high modulation freqeuncy, which is different from the half-wavelengh fringe in traditional two-beam-interference. Without electronic subdivision, it naturally has the nanoscale optical resolution (4nm or even higher) traceable to the laser wavelength. Based on this principle, two experimental schemes are designed to realize traceable nanomter measurment, combined with the newly-innovated technologies of orthogonal phase, polarization flippiing, and frequency stabilization by equalizing the intensities. This system can be appled not only to measure the displacement with naonmeter accuracy, but also to calibrate other displacement sensors, such as laser interferometer.

纳米测量是纳米科技发展的基础，如何实现可溯源的纳米测量一直是国际上尚未很好解决的基础性科学问题。它不但要求具有纳米级的分辨率，而且还需具有溯源性，同时考虑环境扰动、系统复杂程度及成本等因素。本申请提出一种基于激光纳米条纹的纳米溯源新原理，利用激光高阶回馈效应，产生高倍频的激光回馈条纹。该条纹与传统的双光束半波长干涉条纹不同，无需电子细分，它天然具有纳米级的光学分辨率（4nm甚至更高），可溯源到激光波长。基于此，设计了平凹腔和直角棱镜阵列回馈两种原理方案，结合相位正交、偏振跳变、等平均光强动态稳频等创新技术，实现纳米溯源测量。采用该原理的测量系统不但可以用于纳米级的高精度测量，而且还可以用于标定其他的位移传感器,如激光干涉仪。

高分辨率、可溯源的精密测量是工业制造和科学研究的前提和基础，如何实现可溯源的纳米测量一直是国际上尚未很好解决的基础性科学问题。它不但要求具有纳米级的分辨率，而且还需具有溯源性，同时考虑环境扰动、系统复杂程度及成本等因素。本课题针对目前国际上现有研究的不足和缺口，提出了新的纳米溯源测量原理，利用激光回馈效应中的高阶回馈效应，提出平凹激光谐振腔和直角棱镜阵列回馈两种原理方案，将传统的激光回馈波形倍频，分别进行实验验证，选择稳定度强、分辨率高的角锥棱镜阵列回馈方案，搭建实验系统验证性能指标后，进行相应的仪器化设计与配套的机械、电路设计，研制了两类仪器原理样机（包括光学，细分电路和数据处理软件），分辨率分别为0.51nm和0.13nm，测量范围大于100μm，等光强动态稳频精度优于10-7，测量结果可溯源，对环境扰动具有强鲁棒性。在对激光回馈机理的探索中，研究了激光回馈效应中正交偏振激光纳米条纹的产生机理，稳定的具有90°相位差高阶回馈信号的实现，以及回馈镜运动方向与激光器的偏振态、回馈条纹的相位关系，补充了激光回馈效应的原理研究，扩展了高阶激光回馈的精密测量应用。