Compact delay structure based on photonic crystal waveguide loop

A new compact delay structure based on two-dimensional photonic crystal (PC) is presented. The delay structure consists of a PC waveguide loop and a PC coupler switch. The optical signal pulse is delayed when it circulates in the waveguide loop, and the delay process is controlled by the coupler switch. After the theoretical analysis and design, the behavior of the delay structure is verified using the finite-difference time-domain method.