Photonic integrated circuit

An optical receiver, comprising:

• a local oscillator (LO) laser having first and second sides and outputting first light from the first side and second light from the second side;
• a coupler that receives the first light, the coupler having first and second outputs, the first output supplying a first portion of the first light and the second output supplying a second portion of the first light;
• a first optical hybrid that receives the first portion of the first light;
• a second optical hybrid that receives the second portion of the first light;
• and
• a control circuit optically communicating with the second side of the LO laser, the control circuit receiving at least a portion of the second light and monitoring the second light.

An optical receiver, comprising:

• a local oscillator (LO) laser that output light;
• a first coupler that receives the light, the coupler having first and second outputs, the first output supplying a first portion of the light and the second output supplying a second portion of the light;
• a second coupler having an input that receives the first portion of the light, the second coupler having a first output that supplies a third portion of the light and a second output that supplies a fourth portion of the light;
• a first optical hybrid circuit that receives the third portion of the light;
• a second optical hybrid circuit that receives the fourth portion of the light;
• and
• a control circuit optically communicating with the second output of the first coupler, the control circuit receiving at least a portion of the second portion of the light, the control circuit monitoring the second portion of the light.