Patent ID: 9673900
Date: 2017-06-06
CPC Classifications: H04B,H04L,H04Q

Claim:
1. An optically synthesized tracking signal source comprising: a first square-law photodetector configured to provide a first output signal having a frequency equal to a frequency difference between optical signals of a first pair of optical signals; a second square-law photodetector configured to provide a second output signal having a frequency equal to a frequency difference between optical signals of a second pair of optical signals, the second optical signal pair being a frequency-shifted version of the first pair of optical signals; and an optical wavemeter configured to determine one or both of the frequency difference between optical signals of the first pair of optical signals, and the frequency difference between optical signals of the second pair of optical signals, wherein the first and second output signals are tracking signals having a frequency offset determined by a relative frequency shift between the first and second pairs of optical signals.