Patent ID: 9369209
Filing Date: 2016-06-14
CPC Classification: G02B,H04B

Claim Text:
1. An apparatus, comprising: a first optical input coupler, having first and second input ports and first and second output ports, and configured to receive an optical input signal to the first input port, wherein an optical power level ratio of a second optical output to first optical output transmitted from the second and the first output ports, respectively, equals about 2:1; a second optical input coupler having third and fourth input ports and third and fourth output ports, and configured to receive the optical input signal to the third input port and transmit a third optical output from the third output port to the second input port of the first input coupler, and transmit a fourth optical output from the fourth output port, wherein optical power level ratio of the fourth optical output to the third optical output, equals about 4:3, respectively; and a third optical input coupler having fifth and sixth input ports and fifth and sixth output ports, and configured to receive the optical input signal to the fifth input port, and, transmit a fifth optical output from the fifth output port to the fourth input port of the second input coupler and transmit a sixth optical output from the sixth output port, wherein an optical power level ratio of the sixth optical output to the fifth optical output, equals about 8:7.