Patent ID: 9482886
Filing Date: 2016-11-01
CPC Classification: G02F,H04B

Claim Text:
1. An integrated optical linewidth reduction system comprising: a first splitter/coupler adapted to split an incoming optical signal into at least first and second optical signals travelling through first and second optical paths; a second splitter/coupler adapted to split the second optical signal into at least third and fourth optical signals travelling through third and fourth optical paths, said third optical path having a longer propagation delay than said fourth optical path; a third splitter/coupler adapted to generate a fifth optical signal by coupling a first portion of the third optical signal with a first portion of the fourth optical signal and deliver the fifth optical signal to a fifth optical path, the third said splitter/coupler being further adapted to generate a sixth optical signal by coupling a second portion of the third optical signal with a second portion of the fourth optical signal and deliver the sixth optical signal to a sixth optical path; a photo detection circuit comprising first and second photo detectors, said first photo detector being adapted to generate a first electrical signal in response to the fifth optical signal, said second photo detector being adapted to generate a second electrical signal in response to the sixth optical signal, said photo detection circuit supplying a third electrical signal in response to the first and second electrical signals; said third electrical signal being representative of a phase noise of the incoming optical signal; a phase modulator adapted to modulate the phase of the first optical signal in response to a control signal defined by the third electrical signal; a phase wrapper adapted to generate the control signal from the third electrical signal, said phase wrapper comprising: a phase rotator adapted to generate an in-phase signal and a quadrature-phase signal in response to the third electrical signal; and an inverter adapted to perform a modulo operation on the in-phase and quadrature-phase signals.