光纤型白光干涉仪光程差的超分辨率识别

Super-resolution Identification of Optical Path Difference of Fiber-optic White Light Interferometer

提出了一种白光干涉仪干涉信号超分辨率识别的方法。白光干涉信号之间的光程差小于相干长度(通常为50μm)时会发生叠加,叠加导致信号形状发生畸变无法区分。首先从理论研究推导出重叠引起的干涉信号面积变化大小与光程差之间的关系,然后利用重叠导致的面积变化推导出信号真实的光程差从而到达超分辨率识别的目的。实验设计制造并识别了光程差为15μm左右的干涉信号,证明了该方法具有提升3倍分辨率的可行性。将有利于提高光程差绝对测量的分辨率。

A numerical method of processing data obtained by the fiber-optic white light interferometer to identify Optical Path Difference(OPD) super-resolution is presented.Signal will be overlapped when the OPD is less than the coherence length(50 μm),and the shape of the signal is changed and cannot be recognized.Firstly,we theoretically analyzed the relationship between OPD and the size of signal area to be measured.Next,we can calculate the real OPD according to the size of signal area.Finally,the experiment results demonstrate that we can identify OPD of 15 μm and we prove the possibility of obtaining OPD with a resolution exceeding the coherence length of light source by 3 times.We believe this paper is benefit to absolute measurement of OPD.