Research Of Design And Simulation Of Reconfigurable Optical Add/Drop Multiplexer Based On Micro-ring Resonator

With the development of optical communication technology and new business has been emerging, has been promoted the fundamental changes in optical networks. The dense wavelength division multiplexing(DWDM) optical network is developing in the direction of all-optical network with optical switching,optical routing and intelligent wavelength distribution. Reconfigurable optical add/drop multiplexer (ROADM), as a key node device in all-optical networks, is developing in the direction of higher performance such as wavelength tunable and crosstalk suppression, and has become a hotspot in the field of optical communication. The basic unit of micro-ring resonator has the advantages of many functions,such as simple structure, small size, high sensitivity and good wavelength selectivity. It has been widely used in the design and manufacture of optical communication devices such as optical filters, optical modulators and optical lighting. The micro-ring resonator provides a new approach to the design of a compact, highly integrated, reconfigurable optical add/drop multiplexer, which studies the reconfigurable optical add/drop multiplexer based on the micro-ring resonator structure. The development of great significance.In order to overcome the traditional structure of the optical add/drop multiplexer that can not achieve lower crosstalk, lower loss and tunable characteristics in the optical transmission backbone, so this paper has improved an excellent performance based on micro-ring resonantor of ROADM. The main contents and results are as follows:(1) On the basis of extensive reading of domestic and foreign literature, it is concluded that the research of ROADM is not fast enough, the integration is not high, and nowadays it is not much to the high-speed integrated ROADM device. Based on the current research on the micro-ring resonator, this paper focuses on the micro-ring resonator of ROADM, and analyzes the basic model, working principle and performance parameters. And then uses the coupled-mode theory and the transfer matrix method that analysis the output amplitude,output spectrum, insertion loss and crosstalk of ROADM, and the numerical simulation. The lay the theoretical foundation for the design and optimization of the ROADM.(2) Aiming at the shortcomings of crosstalk and scattering loss at the intersection of traditional rectangular cross waveguide, a cone-shaped multimode interference principle is introduced at the cross, and a tapered multimode interference cross-waveguide is designed.The simulation results show that the cross waveguide can achieve the characteristics of small size, low crosstalk and low loss. The ROADM model of the conical single ring resonant structure is constructed by using the conical cross waveguide instead of the traditional rectangular waveguide. The output spectrum, crosstalk and output power are simulated. The simulation results show that the output spectrum of the structure is symmetrical with the traditional structure, the resonant peak is flat and the crosstalk is almost no, and the output power is increased by 16%. It is shown that the linear conical structure can achieve the lower loss optical transmission very well.(3) A four-channel reconfigure optical add/drop multiplexer with excellent characteristics is proposed, which is based on linear conical cascade four-ring structure of ROADM. The working principle and basic functions of ROADM of four-ring structure are analyzed, and the principle of thermo-optic tuning is introduced. The ROADM characteristics of the traditional four-ring structure and the linear conical four-ring structure are analyzed by FDTD algorithm. The simulation results show that the ROADM of the linear conical four-ring structure has weak non-resonant light and flat response of the box spectrum, and the insertion loss of each channel is low, and the advantages of small crosstalk. When control the heating power of the heating plate,the structure can be dynamically down-loaded different wavelength signal. So it is of great reference value for the future of design of large-scale ROADM device.