Patent ID: 6162655
Filing Date: 2000-12-19
Classification: G02B,H01S

Abstract:
A method of fabricating an optical waveguide, semiconductor device, which has an axis along which an optical beam propagates, comprising the steps of:(a) forming a first semiconductor waveguide region having first and second sections of different thickness and an intermediate vertical taper section of varying thickness coupling said first and second sections to one another, said first waveguide region being effective to expand the size of said beam as it propagates from said first section to said second section,(b) forming a second semiconductor region on said first waveguide region,(c) etching said second region so as to form an essentially vertical first surface of length A-B which extends obliquely across said axis,(d) forming a third semiconductor region on said second region and over said first surface, and(e) etching an elongated mesa along said axis, said mesa extending through at least said second region and said first surface so as to form a second waveguide region having an oblique, essentially vertical second surface which has a length a-b<A-B and which is a subsection of said first surface, said second surface forming an asymmetric horizontal taper effective to optically couple said beam between said second waveguide region and said first waveguide region.