Wavelet transform applied in the micro-displacement measurement of wavelength scanning Febry-Perot interferometer

摘要

In this paper, the characteristics of wavelength scanning micro-displacement measurement signal is analyzed, and it is pointed out to be uncontinuous and unstable, so using Fourier transform to process must bring about error. Because of wavelet transform having good localization property in time-frequency domain and strong effects for the filtering of white noise and sharp pulse, it can overcome shortcomings of original signal's edge fuzzy caused by average filtering and median filtering. In this paper, wavelet transform is applied to process detected displacement signal in the wavelength scanning Fabry-Perot interferometer. Theory and test have shown that using this method is more accordant with reality of optical measurement and can eliminate noise. The measurement resolution and precision can be improved.