加权多步波长移相算法研究

波长移相干涉技术通过改变光源的波长实现移相,可以克服硬件移相引入的误差,同时原理上可以实现多组干涉信号的分离。主要应用于大尺寸干涉仪及需要分离多表面干涉信号的系统中。加权多步波长移相算法是其主要的算法,中心思想是通过时域加入合适的窗函数,抑制寄生信号,提出包含轮廓或厚度信息的有用信号。文中介绍其设计思想,进行算法设计,并对一光学件进行了测试和比对。

Weighted Multi-step Phase-shifting Algorithm via Wavelength Tunning

Phase-shifting interferometry via wavelength tunning, which achieves phase-shifting by changing optical source wavelength, can eliminate the error caused by hardware phase-shifiting and simultaneously may separate from multiple-beam interference signals in the principle. This technique is mainly applied in large aperture interferometer and system requiring parting multiple-surface interference signals. Weighted multi-step phase-shifting algorithm via wavelength scanning is main algorithm of the technique. Its main idea is adding proper window function in the temporal domain in order to suppress unwanted signals and obtain useful signals of profile or thickness. The idea of design is introduced and some algorithms are contrived. Finally, an optical component is measured and compared.