Patent ID: 9678288
Date: 2017-06-13
CPC Classifications: G02B

Claim:
1. An optical circuit comprising: a first optical coupler comprising at least a first input and at least two outputs; and a second optical coupler comprising an input coupled to one of the outputs of the first optical coupler; wherein a ratio of intensity of light reflected from the first input of the first optical coupler to intensity of light inputted to the first input of the first optical coupler is smaller than a ratio of intensity of light reflected from the input of the second optical coupler to intensity of light inputted to the input of the second optical coupler, and wherein the first optical coupler is an MMI coupler, the first input and the second input have tapered shapes, and width of the taper of the input used as the main input is larger than width of the taper of the input used as the reserve input.