Patent ID: 8548337
Filing Date: 2013-10-01
Classification: H04J

Abstract:
1. A phase lock apparatus to phase lock light from a laser to an input optical signal, said phase lock apparatus comprising: a splitter; a sampled coherent detection means; an optical phase adjuster; a digital to analog (D/A) converter; and a digital signal processor; wherein: light from said laser is divided by said splitter into first and second branches; light in said first branch is combined with the input optical signal in said sampled coherent detection means so that said digital signal processor knows the optical phase difference between light from said laser and the input optical signal; light in said second branch is modulated by said optical phase adjuster; said optical phase adjuster is adjusted by at least one analog control voltage, said analog control voltage being produced by said D/A converter; and said D/A converter is controlled by said digital signal processor; whereby the light from said optical phase adjuster is phase locked to the optical input signal.