文档介绍：基于取样光栅的梳状滤波器研究
摘要
取样光纤光栅是一种新型的光纤光栅,因其具有灵活,无源,插入损耗小,及偏振相关小等优点,它在光开关、光的分插复用、光纤的色散补偿等关键技术中的应用引起人们的极大兴趣和研究热情。
本文用传输矩阵法从理论上计算了取样光纤布拉格光栅的反射谱特性,这种方法将光栅视为多层均匀薄膜的叠加,利用每一层的传输矩阵相乘获得了光栅的反射谱特性。通过分析知道了取样光栅具有极好的波长选择性,在它的反射谱中通道多且通道间隔稳定,带通窄,在光信号处理中有重要应用。
对取样光纤光栅反射谱特性进行了分析,通过分析取样光栅长度、取样周期、采样率、折射率调制量等参量对取样光栅反射谱的影响规律。为设计取样光栅提供了一定依据。通过matlab软件分析取样光栅各参量对取样光栅反射谱的影响。设计了取样光栅滤波器。最后,为了优化取样光栅梳状滤波器设计,提出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。
关键词取样光栅;耦合模理论;传输矩阵法;梳状滤波器;经验模态分解
Abstract
Sampled fiber grating is a novel fiber grating, as it has low-cost, flexibility, low polarization dependent loss and low polarization model dispersion , it have caused people's great interest and enthusiasm such as optical switch, optical add/drop multiplexer, and optical fiber's pensator, etc.
Reflective spectral properties of sampled fiber Bragg grating is theoretically calculated by transfer matrix method in this paper. With this method, the grating is regarded as the overlapping of multi-layeruniform thin film and the reflective spectral properties of the grating are calculated by multiplyingtransfer matrix of each layer. Through numerical analyzing we know that the reflective spectrums of sampled grating have very good wavelength selectivity. There exist multiple channels in the reflective spectrums, the spaces between the channels are stable, and the bandwidths are narrow. Finally,in order to optimization the design of sampled b filter, a filtering analysis and denoising method by using EMD was proposed.
Keywords Sampled fiber grating; coupled mode theory; transfer matrix; Comb filter; EMD
目录
摘要 I
Abstract II
第1章绪论 1
课题背景 1
2
3
光纤布拉格光栅滤波器 3
相移长周期光纤光栅滤波器 3
啁啾(Chirped)光栅宽带滤波器 3
光纤光栅梳状滤波器 4
4
幅度取样方案 4
啁啾效应 4
相位取样方案 5
6
6
论文的主要目的 7
第2章取样光纤光栅的基本理论 8
8
8
8
光纤光栅的分类 9
10
11
12
1