Fabrication Tolerance Analysis of Bent Single-Mode Rib Waveguides on SOI

Abstract

The influence of fabrication tolerances on the minimum bending radius of both rectangular and trapezoidal single-mode rib waveguides on silicon on insulator (SOI) is analyzed. In order to reduce the number of simulations, we present a semi-analytical procedure which yields an estimation of the bending radius, and facilitates the interpolation of the obtained data. We conclude that the tolerances of today’s fabrication processes hinders the miniaturization of integrated circuits if single-mode behavior is required. Besides, the sidewall angle tapering in 90° turns of wet etched waveguides is analyzed in a worst case approach.