Silicon waveguide grating coupler based on a segmented grating structure

Appl Opt. 2018 Apr 20;57(12):3301-3305. doi: 10.1364/AO.57.003301.

Abstract

We present the simulation, fabrication, and experimental results of a high-efficiency and wide-bandwidth segmented waveguide grating coupler on a silicon-on-insulator platform for near vertical optical coupling between the waveguide and optical fiber. The coupler comprises segmented gratings, which can increase vertical coupling to the optical fiber and reduce backward reflection. The proposed grating coupler has a 3 dB bandwidth of 71.4 nm and a coupling efficiency of 51.7% at a wavelength of 1550 nm. Compared with the standard uniform waveguide grating coupler, the coupling efficiency was improved by 25.64%.