基于波长移相的改进加权多步算法

在斐索干涉仪中测量光学平板受到多面反射光束的影响,而波长移相干涉技术是通过光源波长的改变来实现干涉信号的移相,原理上可以实现各个干涉信号的分离,在算法上要求能对多次谐波进行较好的抑制,加权多步移相算法可以实现这样的目的.笔者提出了加权多步移相算法的改进算法,可以提高算法对误差的抑制能力,最后用实验验证了改进算法的有效性.

Weighted multi-step phase-shifting algorithm developed via wavelength tuning

The testing of the flatness of an optical parallel plate in a Fizeau interferometer suffers from the problems caused by multiple-beam interference. The interferometer of wavelength tuning realizes phase-shifting by changing the wavelength of the laser source. In principle, this kind of interferometer can distinguish parasitic interferential signals. Therefore, good ability is required in the algorithm to suppress multi-harmonic waves. The weighted multi-step algorithm can realize this purpose. This paper puts forward an advanced weighted multi-step algorithm which can further suppress errors. Finally, the new algorithm is testified by experiments.