Design of 4x4 GaAs-GaAlAs carrier-injected total internal reflect optical switch array

A new scheme of GaAs-GaAlAs total-internal-reflect (TIR) optical switch unit based on bandfilling effect is presented in this paper. Asymmetric Y-branch, which is the essential part of switch structure, is analyzed using beam propagate method (BPM) on three different conditions: index change due to injection, width of injection region and position of injection edge. Unit with two perpendicular output ports is designed according to the numerical results to realized small sized 4 X 4 array which can easily couple with fibers and quickly give off heat.