波长移相干涉仪的算法研究(英文)

Algorithms of the phase-shifting interferometer via wavelength tuning

叙述了波长移相干涉仪的基本原理,分析了其特点,对传统硬件移相干涉仪和波长移相干涉仪进行了比较,指出了它们的优缺点和应用范围。以美国NewFocus公司的可调谐半导体激光器为例,简述了实现波长调谐的硬件。文中将波长移相干涉仪算法分成三类:加权多步波长移相算法、基于傅里叶变换的波长移相算法和多波长算法,对这三类算法进行了较详细的叙述和分析,指出了各自的优缺点和应用范围。基于傅里叶变换的波长移相算法,提出了结合差分运算的适合于台阶测量的新算法,克服了已有算法中需要参考基准和参考面的缺点,提高了算法的实用性。

This paper describes the basic principle of wavelength scanning interferometer and analyzes its characteristics. Their merits and application fields are shown by comparing wavelength scanning interferometer with conventional hardware phase-shifting interferometer. For tunable semiconductor laser from American New Focus Company as example, hardware of realizing wavelength tuning is depicted simply. Algorithms of wavelength scanning interferometer are divided into three kinds: weighted multi-step phase shifting algorithm, the algorithm based on Fourier-transform technique and multi-wavelength algorithm. Their merits and application areas are pointed out through narrating and analyzing them in detial. Furthermore, a new algorithm based on Fourier-transform technique combining with different calculations is proposed, which is suitable to measure steps. The new algorithm overcomes the disadvantages of old one needing datum reference and plane of reference, increasing this algorithm's utility.