Evanescent field maximization of linear silicon nitride channel waveguide

Abstract

Sensitivity of evanescent field sensor is highly affected by strength of evanescent field with respect to its penetration depth and intensity. However in most cases, evanescent field is not maximized and thus the performance of the sensor is not optimized. It is the aim of the paper to optimize the silicon nitride linear waveguide through simulation by using 3D FD-BPM. The resultant investigation shows that evanescent field is maximized at TM polarization, 0.9μm thickness and 4μm width waveguide. Besides, result also shows that TM-polarization results in 15.5 times stronger evanescent field at optimized physical dimension compared to TE polarization.