Patent ID: 6993225
Filing Date: 2006-01-31
Classification: G02B

Abstract:
1. A method of forming a tapered evanescent coupling region for use with a relatively thin silicon optical waveguide layer, the method comprising the steps of: a) providing a polished silicon substrate including a top major surface and an opposing bottom major surface; b) depositing a photoresist material across the top major surface of the silicon substrate provided in step a); c) patterning said photoresist surface to define a tapered area of photo resist material; d) etching the patterned surface to transfer the tapered pattern from the photoresist into the underlying silicon substrate material, forming a tapered opening in the silicon substrate; and e) filling the tapered opening with a material exhibiting a lower refractive index than the silicon substrate, said filled region defining the tapered evanescent coupling region.