一种基于梳状滤波器的固体腔厚度测量方法

Measure Method with Solid Cavity Thickness of Optical Comb Filter

针对密集波分复用(DWDM)技术中所使用的梳状滤波器,对固体腔研磨厚度指标要求极高Δν=200GHz,Δd≤13.37nm,本文提出运用法布里-珀罗干涉理论(Fabry-Perot),研究设计了一种针对固体腔厚度的现场检测方法。该方法根据被测元件等效为系统干涉腔的间接测量方法,以通过被测元件后的法珀相邻能量极值特性,作为检测厚度合格的判定依据,实现了对超窄带梳状滤波器组成元件——未镀膜层固体腔(SiO2)的高精度厚度检测。实验结果表明,该测量方法适用于对透光介质的厚度检测。

According to the theory of Fabry-Perot （F-P） interference, the measurement of no plated membrane light filter is implemented by choosing flat glass （SiO2） as interferometric cavity of the measurement system, and adopting the method for measuring the extremum between two nearby interfered lights. It is the most important part of the new Ultra-narrow Bandwidth filter. Based on solid-cavity thickness of supper narrow band optical comb filters, the precision of height measurement comes true. Experimental results indicate that the accuracy of the optical measurement system with simple configuration and low-cost reaches subnanometer level, as well as strong anti-jamming and stabilization. The system can be adapted to measure transparent medium such as plat-glass, filters, optical coating as well as no plated membrane filters.