Efficient coupling to slow light in a silicon slot waveguide with internal corrugations

Abstract

We modeled, simulated and experimentally observed efficient slow light coupling to internally corrugated slot Bragg grating (ICSBG) waveguide on a silicon-on-insulator platform. A short step taper is utilized to evanescently couple to the slow light mode near the stopband edge, resulting in minimization of Fabry-Perot reflections due to group index mismatch and a minimum slow light coupling enhancement of similar to 1 dB. This is important as it results in a lower insertion loss ICSBG waveguide, which is capable of low loss slow light propagation and therefore is an attractive option as a phase shifter structure for an on-chip slow light enhanced electro-optic modulator or integrated optic sensor applications.