Analysis of Silicon Channel Waveguide Thermo-Optic Switches by the Image Charge Method

Employing the “image charge” method, we theoretically study the influence of key physical parameters on the thermo-optic characteristics of a channel waveguide silicon-on-insulator (SOI) Mach-Zehnder Switch. The power consumption and spatial temperature profile of such structures are given as explicit functions of various structural, thermal, and optical parameters, offering physical insight not available in finite-element simulations. Agreement with finite-element simulations is demonstrated. The trends of switching power versus various parameters provide quantitative guide for further device optimization. This approach may also be useful for efficient modeling of an integrated optical circuit containing a large number of thermo-optic devices.