Analysis Of Coupling Characteristics Of A Novel EO Modulator Based On Resonant Micro-ring

High-speed electro-optical modulator is one of the most important components in optical communication system, which is vigorously developing recently. But the cost of high-speed electro-optical modulators is so high that seriously affects the development and popularization of optical communication in our country, so developing a novel low-cost high-speed electro-optical modulator is becoming one of the key issues related to the optical communication system.Founded on a novel high-speed polymer electro-optical modulator that is based on resonant micro-ring, this paper focused on the analysis of the vertical coupling between micro-ring and channel waveguide and the optimization of the waveguides' parameters. The main results and innovations are as follows.1 Some implementation methods commonly used in the laboratory of attaining the radiation power from the shackles of the channel waveguide were compared. Then axial-side rubbing of fiber was chosen as the experimental manner in the manufacture of the novel modulator. In theory, how light power changed before and with the rubbing going on was analyzed, and the conclusion that the appropriate depth of rubbing is from 51.42 to 57.8μm was drawn. In the manufacture of the novel modulator, 57.5μm was selected as the rubbing depth.2 Characteristics of the vertical coupling between micro-ring and straight waveguide were analyzed by the use of coupling function and transfer matrix. Then based on the theoretical results of rubbing, the optimal parameters were obtained. The influence of bend radius of micro-ring and coupling offset on the coupling coefficient, ratio of power coupling, ratio of power transmission, and the light powers of the micro-ring and channel waveguides were mainly discussed.3 Structure parameters of micro-ring waveguide were optimized in accordance with the performance parameters of micro-ring resonator. Then the resonant condition was verified through the light transmitting function of micro-ring resonator. Characteristics of the transmitting function and performance parameters of the micro-ring resonator were also analyzed. And in order to improve the free-spectrum range and quality factor, thereby to meet the practical application of systems, some available concepts such as optimizing the waveguide parameters (bend radius and effective refractive index) and having multi-ring in series parallel manners were put forward in this paper. 4 After technology groping, the experiment of axial-side rubbing of long fiber was achieved. The maximum length of axial-side rubbing was 14cm, and the precision of rubbing could reach 0.01μm in theory. From the comparison of experimental result and theoretical result, the conclusion that the changing regularities were basically the same was drawn. And after several experiments, the optimal technology parameters were gained when the rubbing depth reached 57.5μm.