Phase-shift algorithm research based on multiple-beam interference principle
基于多光束干涉原理的相移算法研究

Aiming at the application of precision measurement of length, the phase shift algorithm including algorithm error and optimum range of the phase shift step was studied by using the multiple beam interference principle in this paper. We have derived an accurate formula for the intensity distribution of multiple beam interference (multiple reflection by and transmission through the optical surface) in the basic principle of interference optics. Based on this formula and the numerical analysis technique, we have found the optimum value of the phase shift step and the applicable range of the initial phase difference between interference beams by using the precision measurement of length with Fizeau interferometer.We also found the respective relationships between the original phase error and the phase of four step algorithm (and of the five step algorithm) due to the intensity error from cosine dependence. We have assessed the uncertainty from several main error sources of the multiple beam interference.