Unidirectional transmission analysis of all-optical routers with asymmetric structured photonic crystals based on FDTD

The unidirectional transmission behavior of photonic crystal (PC) consisting of defect pairs is investigated by the finite-difference time-domain (FDTD) method. By selecting the appropriate size proportion of the constitutional PC defects and changing the power intensity of the incident light, the transmission contrast as well as the maximum transmission can be significantly improved. The simulation results are supported by the coupled-mode theory(CMT). This conclusion provides a reference for the design of an all-optical router with low insertion loss.