Analysis And Research Of Multi-Carrier Generation Applied In High-Speed Large-Scale Long-Haul Optical Transmission System

As the development of cloud computing, video application and other new technology, tremendous growth in the demand for data traffic is appeared. With the advantage of high-speed, large-scale and ultra-haul transmission, optical transmission systems has become an important solution to satisfy the increasing bandwidth demand. The transmission system with T bit level will appear in the foreseeable future. Due to the limit of electronic device, multi-carriers communication is the main solution to realize the T bit transmission. Laser array are used in some schemes to support the demand of optical source, which would increase the system cost. And the performance of the whole system would be affected due to the difference in some parameters among the lasers. The generation technology of multi-carrier optical source, which provide large amount of stable frequency tones using one or few laser, is becoming an optimize substitute for optical source to achieve the T bit level transmission.The generation scheme of multi-carrier optical source is divided into the Supercontinuum utilizing the nonlinear in fiber, the mode-locked laser, the cascaded electro-optic modulator and the structure of cyclic frequency shift. Due to advantage of the low RF driven voltage and the controllable space between the adjacent carriers, the schemes based on the cyclic frequency shift are research by more institutions.In this paper, we focus on the generation scheme of multi-carrier optical source and propose the improved scheme based on the relevant technical background and theoretical support. A series of studies are conducted by simulation and experiment as follow.(1)The background and status of the generation of multi-carrier optical source are shown;(2) Analyze the principle of the structure of cyclic frequency shift, and introduce application of the key experimental equipment used in some schemes;(3)the derivation and theoretical research are made to analyze the generation scheme based on the single-sideband modulation and cyclic frequency shift, and the relevant simulation platform is built to verify the validity; the research on the factors which affect the performance of multi-carrier optical source is made in the comparison of theoretical derivation and simulation;(4) The improved multi-carrier generation scheme based on cyclic frequency shift is proposed. With the introduction of improved module, the number of multi-carrier gets double with little performance sacrifice. The experimental platform corresponding to the improved scheme is built to generate the stable and flat multi-carrier optical source which verify the validity and practicability.In summary, this paper research on the generation scheme of multi-carrier optical source and propose the improved scheme based on the cyclic frequency shift through the theoretical analysis and simulation. And the validity and practicability are verified by the excellent output from the experimental platform.