Finite element modeling of coupling characteristics of directional coupler for multiplexer and de-multiplexer application

Abstract Numerical simulation of directional coupler that is based on the finite element method was conducted using COMSOL Multiphysics software. The distributions electric field and power flow light propagates in two cores were analyzed. results showed dependencies coupling length maximum transfer between separation wavelength, characteristic a subwavelength can be used for photonic integrated circuits. Asymmetric also designed by changing device dimension, as core width. variation with width analysed. It found switching reduced when introducing small difference one coupler, followed increased length. At same time, decreased efficiently increasing width; therefore, large more convenient to reduce than smaller This study useful determining characteristics may platform future circuits optical communication systems.