用于绝对距离测量的波长扫描干涉仪信号分析

Signal Analysis of Wavelength Scanning Interferometry for Absolute Distance Measurement

提出了一种可用于绝对距离测量的波长扫描光纤干涉仪。在时域和频域上，对其输出信号进行了研究。理论分析了法布里－珀罗腔多光束干涉所产生的干扰以及扫描过程中波长的随机漂移对输出信噪比的影响。由此提出了外腔光源结构和加工精度的要求，并设计了相应的信号处理算法，达到了距离测量所要求的０．０５μｍ的精度和０．

A novel wavelength scanning fiber optic interferometer for absolute distance measurement has been proposed. The output signals from two interferometers are analyzed in time and frequency domains. The influence of multi beam interferences, and the relation between the signal to noise ratio and the random drifts of the scanning wavelength are deduced. From those deductions, some demands upon the design and production of the tunable external cavity semiconductor laser are posed. Based on the conclusions in this paper and the digital signal processing techniques, an effective algorithm is established. So that the precision of 0.05 μm and resolution of 0.01 μm can be satisfied.