Patent ID: 9158175
Filing Date: 2015-10-13
Classification: G02F

Abstract:
1. An optical coupler comprising: a substrate; a first optical waveguide positioned on the substrate; a second optical waveguide positioned on the substrate, the second optical waveguide extending adjacent to and parallel with the first optical waveguide for at least one effective coupling length, the at least one length having a first end and a second end, the second optical waveguide coupled with the first optical waveguide such that an optical signal applied only to the first optical waveguide couples to the second optical waveguide between said first end and said second end; a first phase shift section forming a portion of the first optical waveguide, the first phase shift section located at a first predetermined distance from the first end of the length; and a second phase shift section forming a portion of the second optical waveguide, the second phase shift section located at a second predetermined distance from the second end of the length, wherein the first predetermined distance is approximately equal to the second predetermined distance, and wherein the second optical waveguide does not have a phase shift section forming a portion of the second optical waveguide and located at the first predetermined distance from the first end of the length.