Study On The All-Optical Switch Technology Based On Nolm And Application In The Optical Communication System

Under the promotion of new generation of the optical communication technology based on WDM, OCDMA and the microwave photonics, the rapid development of optical signal processing and transmission has been greatly made, which will definitely result in great demand for photonics devices. All-optical fiber devices consisting of nonlinear fiber loop mirror (NOLM) with high speed and simple as well as convenient controllable structures have been attached importance on, and will have wide application in the areas of various civil and military systems as well as optical communications. Considering the impacts of polarization mode dispersion (PMD), higher-order dispersion, cross-phase modulation (XPM) and stimulated Raman scattering (SRS) on the optical signal along with the dismatches between the control and signal optical fields, the high speed optical signal impairments with bulky capability transmitting in a NOLM have been investigated in detail in this paper.The paper begins with a detailed introduction to the development of optical communication systems based on WDM, OCDMA and the microwave photonics, as well as key devices at high speed, and discusses the current researches and applications of NOLM in Chapter 1. In addition, the main factors including PMD, XPM, SRS and jitter which should influence the performances of NOLM are analyzed.In Chapter 2, the lightwave transmission equations including the higher-order dispersion and the higher-order nonlinear in SMF are given based on the nonlinear fiber optics. Then the optical signal transmission models and power transmission function in the NOLM with two couplers are derived and established. Finally the simulation platform for a NOLM is developed, which provides the conventional tool for analyzing and designing the NOLM based devices.In Chapter 3, the impacts of PMD, XPM and SRS on optical pulses and analog optical carrier in NOLM are numerically analyzed, and the transmission impairment induced by these factors is proved.In Chapter 4, theoretical models of signal jitter in NOLM with two couplers are established. The impact of the polarization mismatch between the control and signal optical fields on digital optical pulses and analog optical carrier, and the impact of the time and phase dismatches on digital optical pulses are numerically analyzed. Furthermore, the impact of the wavelength drift is discussed.In Chapter 5, the PMD compensation solutions are put forward, and the optical switch with high speed based on high birefringence nonlinear-chirped FBG-NOLM (HN-FBG-NOLM), the higher-order soliton compressor based on DDF-NOLM and the encoder/decoder in the OCDMA system based on NOLM-superstructure FBG (NOLM-SSFBG) are numerically analyzed.