Propagation Effect Of Three-Core Coupler And Varying Coupling Coefficient Coupler

Along with photonics technology and optical fiber communication technology and the rapid development of various types of optical devices, and also tend to improve as the theoretical basis of the optical fiber transmission-Optical Waveguide Theory, Optical passive devices widely used in various aspects of optical fiber communication, optical fiber technology to further the development and application. With high return loss, low insertion loss, high reliability, stability, mechanical wear resistance and corrosion resistance, ease of operation and other characteristics. Widely used in long distance communications, LAN and FTTH, video transmission, optical fiber sensing.Fiber coupler, optical passive devices for transmission and distribution of optical signals is one of the wide range of optical passive devices used in fiber-optic system Occupies a pivotal position in the field of optical fiber communication and fiber sensing. In the current theoretical research, Has also been theoretical studies of the optical transmission characteristics of linear, nonlinear, dispersion, high-order dispersion and other parameters of the coupler, It can be said that the fiber coupler as an optical passive devices development and have reached a more mature stage.In this paper, through the optical waveguide mode theory and mode coupling theory to expand, Dielectric fiber-optic transmission in optical fiber communication, Optical waveguide devices and optical fiber communication systems-fiber grating and fiber couplers study, The major work includes the following aspects:1、 First through the Maxwell equation, Derivation of the light pulses in optical fiber transmission characteristics, including the propagation constant, mode theory, software simulation of light pulses in optical fiber transmission;2、 Through three core coupled waveguide design, three-level system in the simulation of quantum mechanics., Calculate the coupling coefficient and fiber parameters, Optimization of the three core coupled waveguide design of the coupling coefficient contrast, simulation pulse nonlinear propagation in the waveguide, the nonlinear dark state;3、Focusing on fiber grating and fiber couplers, two types of passive devices, including optical coupler dispersion, nonlinear transfer characteristic, Grating dispersion characteristics of the reflective properties and grating parameters; grating the time-domain impulse response; continuous wave, pulse transmission characteristics of the grating coupler;4、The structural disturbances on the transmission characteristics of the coupler, the coupler structure disturbance Fourier expansion of each spatial frequency component of the transmission characteristics of the coupler.