A slanted InP waveguide for fiber coupler using skewed dry etching process

We propose a simple and efficient off-chip coupler for vertical coupling between optical fibers and InP-based slab waveguides. Etching angle of the waveguide edge is controlled by an etching jig made of SiO2-coated aluminum for ICP-RIE. Simulation shows that maximum 71% coupling efficiency would be obtained by matrix expansion methods.