Patent ID: 6868102

Claim:
A generator of a CS-RZ optical clock signal at a predetermined clock frequency, the generator comprising: a first laser source and a second laser source respectively producing first and second continuous lightwaves, the laser frequency of at least one of said sources being adjustable; coupling means disposed to receive the first and second lightwaves and suitable for forming optical beats at a beat frequency; and an opto-electronic feedback to servo-control the adjustable-frequency laser source(s) in such a manner that the beat frequency which is equal to the difference between the laser frequencies is substantially equal to the clock frequency; wherein the opto-electronic feedback loop comprises: optical processing means placed to receive an optical signal representative of said beat and suitable for forming a modified optical signal; converter means placed to receive said modified optical signal and suitable for forming a measurement electrical signal at a frequency substantially equal to the beat frequency divided by an integer greater than 1; and comparator means giving the difference between the frequency of a comparison electrical signal representing the measurement electrical signal and a reference frequency equal to said clock frequency divided by said integer, said comparator means including a control device for adjusting the laser frequency(ies) in response to said difference.