Patent ID: 7447436
Filing Date: 2008-11-04
Classification: H04B

Abstract:
1. A transmission subsystem for a communications system, the transmission subsystem comprising: a wavelength locking device, wherein the wavelength locking device is coupled to receive a first composite signal comprising a first optical signal including a first optical carrier and a second optical signal having a second optical carrier, and a second composite signal; an optical filter, wherein the optical filter is configured to produce the second composite signal by filtering the first composite signal such that a lower optical sideband of the first optical signal and a an upper optical sideband of the second optical signal are suppressed during said filtering; wherein the wavelength locking device is configured to generate respective indications of the strengths of the first and second optical carriers in the first and second composite signals and lock a frequency separation between the first and second optical carriers using the respective indications of strength, wherein the frequency separation is substantially equal to the bandwidth of the optical filter.