通过改变取样光栅的各参数来仿真其反射谱,调试出四种基于取样光纤光栅的光学梳状滤波器。为了优化取样光栅梳状滤波器功能,提卅了利用经验模态分解对信号进行滤波分析和降噪处理的方法。该方法是将经验模态分解得到的同有模态丽数,分为信号分量起主导作用模态与噪音分量起主导作用模态,去除噪音分量起主导作用模态,并利用反映信号主要结构的模态对信号进行重构实现去噪。文中最后以一种含噪声的反射谱为例,进行降噪后得到平滑的反射谱。
By changing the parameters of sampled fiber grating and simulating its reflective spectrum. Four optical comb filters based on sampled grating were designed. In order to optimization the function of sampled grating comb filter, a filtering analysis and denoising method by using EMD was proposed. This method divide intrinsic mode function obtained by EMD into two mode. One of the mode was that signal components mode play dominant role,the other mode was that( noise component mode plays dominant role. The mode of noise component play dominant role was removed. It can denoise reflective spectrum through restructuring signal. In this paper, reflective spectrum including noise was denoised as an example. The smooth reflective spectrum can be got after denoising.