Research Of Optical Add-Drop Multiplexer Based On Fiber Bragg Grating

At present, with the development of optical communication networks, as one of the key devices of WDM optical network, Optical Add-Drop Multiplexer (OADM) has been the focus of attention. Among OADM structure forms, OADM based on fiber Bragg grating (FBG) has the advantages of low loss, simple structure and insensitive polarization, these advantages make it has a broad application prospects in the all-optical communication network.This paper focuses on the OADM based on fiber grating, respectively studies one based on FBG and circulator and the other one based on FBG and Mach-Zehnder Interferometers (MZI). The main research contents come as follows:1. Firstly, some current structures of OADM are summarized and the developmental of FBG is introduced. Then the basic theory of fiber gratings such as Coupling Mode Theory (CMT), and Transfer Matrix Method (TMM) are analyzed. At last, several apodization methods and tuning methods of fiber gratings are introduced.2. Three structures of OADM based on fiber grating and circulator are studied and simulated, and the results of the simulations of these structures of OADM are analyzed in this paper. The three structures include a tunable FBG OADM, a combination OADM with four fiber gratings and circulators, and a reconfigurable OADM using a circulator of eleven ports.3. OADM based on FBG and MZI are studied and simulated, in which the numerical simulation results of efficiency and isolation are analyzed. Then OADM based on sampled fiber Bragg grating (SFBG) and MZI are studied, with it, downloading spectrums of 16-channel and 29-channel are obtained. At the end, Gauss apodization function has been used to optimize the downloading spectrums.