Patent ID: 7519240
Filing Date: 2009-04-14
Classification: G02B

Abstract:
1. An optical device, comprising: a first optical coupler including a first pair of waveguides separated by a first gap, the first pair of waveguides defining a first coupling region; a second optical coupler including a second pair of waveguides separated by a second gap, the second pair of waveguides defining a second coupling region; a third optical coupler including a third pair of waveguides separated by a third gap, the third pair of waveguides defining a third coupling region, the first, second and third gaps being substantially different from one another such that the first, second and third couplers have substantially different net coupling values; a first differential phase cell provided between the first and second optical couplers, the first differential phase cell including first and second waveguides, and imparting a first differential phase shift between first optical signals propagating in the first and second waveguides of the first differential phase cell; and a second differential phase cell provided between the second and third optical couplers, the second differential phase cell including first and second waveguides, and imparting a second differential phase shift between second optical signals propagating in the first and second waveguides of the second differential phase cell.