An all-optical half subtractor based on Kerr effect and photonic crystals

Abstract Optical half subtractor is one of the optical logic gates, which is very important for realizing all optical computing systems. The aim of this paper is to design a new structure for realizing an all-optical half subtractor based on photonic crystal nonlinear ring resonators. For this purpose, three nonlinear ring resonators are combined with the some optical waveguides to create the desired structure. A finite difference time domain method will be utilized to analyze and simulate the proposed structure. The simulation results show that the contrast ratio for D and B ports are 6.81 dB and 7.78 dB respectively. Moreover, the maximum rise and fall times for the proposed structure are 1.5 ps and 1 ps respectively.