Patent ID: 8314988

Claim:
An optical circuit, comprising: an optical coupler having an input port, an intermediate port, and an output port, the optical coupler configured to receive light on the input port, the light having first and second components, the first component having a first polarization state and the second component having a second polarization state that is different than the first polarization state; a polarization sensitive operator having first and second ports, the first port being optically coupled to the intermediate port of the optical coupler, the polarization sensitive operator configured to receive the first and second components of the light and operate on the first and second components of the light as the light propagates from the first port to the second port of the polarization sensitive operator; and a polarization rotator reflector having a port, the port of the polarization rotator being optically coupled to the second port of the polarization sensitive operator, the polarization rotator reflector including a polarization rotator and a reflector, the polarization rotator being configured to receive the first and second components of the light supplied from the port of the polarization rotator reflector and rotate the first and second polarization states such that the first component is output from the polarization rotator having the second polarization state and the second component is output from the polarization rotator having the first polarization state, the reflector being configured to reflect the first and second components of the light such that the reflected first and second components of the light are output from the port of the polarization rotator reflector to the polarization sensitive operator, wherein the polarization sensitive operator is configured to receive the reflected first and second components of the light at the second port of the polarization sensitive operator and operate on the light as the first and second components of the light propagate from the second port to the first port of the polarization sensitive operator, and wherein the intermediate port is one port from which the first and second components of the light are output to the polarization sensitive operator and the reflected first and second components of the light are received, the optical coupler providing the reflected first and second components of the light at the output port of the optical coupler.