The Study On Characteristics Of Controllable Splitter Based On Photonic Crystal

In today’s era dominated by the high-speed data communication services, the demand of high-speed access network is increasing rapidly. The beam splitter is a key functional devices in the optical access network system, its performance will have a decisive impact on the transmission quality of the system. The controllable photonic crystal waveguide power splitter based on self-imaging effect of multimode not only combine the advantages of photonic crystals and optical switch, but also contain many features of MMI devices, which provide a new way in the field of miniaturized and controllable power splitter.In this paper, firstly, the self-imaging theory and coupling characteristics are analyzed in the five parallel photonic crystal waveguides coupling system when the input is symmetry. Simulation results show that the positions of output waveguides are decided by the positions of periodic twofold image which are formed by the self-imaging effect of multimode interference. The identical output optical power in each output port of the device can be realized by inserting dielectric rod A and B. By simply tuning the radius of rod A and B, the proportionality of energy of four output ports can be0.01dB, the transmittance can be99.6%. Secondly, the principle of photonic crystal optical switches is studied on the basis of that structure, four switches are generated through the introduction of point defects, and tunable photonic crystal resonator is generated when the point defects are filled with GaAs material. By analyzing the impact of point defects on the beam splitter performance,the best point-defect parameters have been identified. Finally, take uniformly distributed photonic crystal power splitter for example, the performance of sixteen kinds of’on-and-off’ control combinations are analyzed.The results show that: whether uniformly distributed or non-uniformly distributed the splitter is, the "on-and-off" control is feasible and the result is obvious, When the output channels is’off’,the energy is almost fully transferred to the other output channels, and the extinction ratio is28dB.When the output channels are all’on’, the insertion loss is0.016dB.And the system response time to109ps,simple structure, easy to fabricate. It is of great significance to realize the controllability of the communication network.