Patent ID: 7184207
Filing Date: 2007-02-27
Classification: G02B,G02F

Abstract:
1. An optical device comprising a semiconductor structure including first and second ridge waveguides, each waveguide comprising a ridge extending across a surface of the semiconductor structure, the ridge of the first waveguide having a first height above a first region of the surface, and the ridge of the second waveguide having a second, greater, height above a second region of the surface, the semiconductor structure including a multimode interference (MMI) region situated between the first and second ridge waveguides and providing a transition between them, and wherein the device includes one or both of the following: (a) at least a part of the MMI region is tapered in width; (b) at least a part of one or both of the first and second ridge waveguides is tapered in width in a direction extending away from the MMI region.