FDTD Research Of Optical Switch Of Two-Dimensional Photonic Crystal Waveguide Coupler

It can be achieved artificially control the flow of light based on Photonic crystal properties of photon localization. Photonic crystal optical switching devices have the advantage which the conventional optical switch devices do not have. Compared to the traditional Optical Switch devices,photonic Crystal Optical Switch has great advantages of the structure, speed, reliability, power consumption, expansibility and so forth, this makes it an ideal choice of integrated optical components in future. In this paper, we focus on the research of two-dimensional photonic crystal waveguide coupler all-optical switch, including:1,We use the finite difference time domain method (FDTD),discussed the common two-dimensional photonic crystal structure, as well as the impact of different lattice constant,dielectric cylinder radius to the location of the band gap, bandwidth and transmission.2,Line defects in two-dimensional photonic crystal waveguide have been many studies, including:Take two-dimensional square lattice photonic crystal as an example, simulated the transmission characteristics of line defects waveguide, and gained the transmission characteristics of incident light with different frequency. At the same time, simulation of the optical transmission characteristics of waveguide with 90°bend, demonstrated its low-loss in optical transmission.Discussed the two-dimensional photonic crystal waveguide coupling structure, principle, and the realization of the coupling function. Choose the appropriate length of the device can be achieved in the coupled-wave energy transfer back and forth between waveguides. At the same time, the design of the structure of a particular coupler can realize the directional coupler function of different frequencies of light. We can djust the structure and parameter design to meet the different needs.3,Discussed a two-dimensional photonic crystal waveguide coupler-based all-optical switch, and used the FDTD method to study its bend gap and transmission characteristics. Numerical calculations show that, suitable for the coupling coefficient and length, can realize the switch function of optical transmission, and reduce the coupling length will reduce the bandwidth. Also established a non-linear model of the FDTD to research non-linear absorption in such structure of optical switch, found that non-linear two-photon absorption has an impact effect on optical switch function. It provides a theoretical basis for future design of this type of optical switch devices.