Stratified waveguide grating coupler for normal fiber incidence.
We propose a new stratified waveguide grating coupler (SWGC) to couple light from a fiber at normal incidence into a planar waveguide. SWGCs are designed to operate in the strong coupling regime without intermediate optics between the fiber and the waveguide. Two-dimensional finite-difference time-domain simulation in conjunction with microgenetic algorithm optimization shows that approximately 72% coupling efficiency is possible for fiber (core size of 8.3 microm and delta=0.36%) to slab waveguide (1.2-microm core and delta=3.1%) coupling. We show that the phase-matching and Bragg conditions are simultaneously satisfied through the fundamental leaky mode.
Wang
Bin
B
Nano and Micro Devices Center, University of Alabama in Huntsville, Huntsville, Alabama 35899, USA.
Jiang
Jianhua
J
Chambers
Diana M
DM
Cai
Jingbo
J
Nordin
Gregory P
GP