The Design of half-subtractor Logic Function Based on Nonlinear Directional Coupler

Abstract

In this paper a novel design of all-optical half-subtractor based on nonlinear directional coupler is proposed. By using four waveguides and appropriately adjusting the refractive indices and selecting the proper length of waveguides, halfsubtractor function can be obtained. The operation of this function is simulated by RSoft CAD-Layout (BeamPROP) simulator. The simulation results confirm the alloptical half-subtractor circuit without any optoelectronic conversions.