A novel design of all optical half-subtractor using a square lattice photonic crystals

摘要

In this research, an all-optical half-subtractor is designed and simulated using two-dimensional photonic crystals. First, a photonic crystal structure is created using Si rods in the air context to obtain the optical half-subtractor. Afterward, using point and line defects, two waveguides are created for the input and two waveguides are created for the outputs. A high logical value and a low logical value are defined based on the optical power in each port. The FDTD method is used in the simulation of light propagation in the structure. The simulation results show that the designed half-subtractor has high optical power values for logic "1" and low values for logic "0". The small size of the designed structure is among the advantages of this structure. Moreover, given that this half-subtractor is devoid of ring resonators, it can be used in high-speed integrated optical circuits. Another advantage of the proposed half-subtractor is that the optical powers in the outputs are similar in the high and low optical states.