Background and description
Multi-Gigabit/Terabit data transmission across very long distance optical fiber networks, such as transcontinental communications, is a big challenge for the state-of-the-art technology. Coherent fiber optical communications have the unavoidable penalty associated with the quality of the two lasers at each end of the channel. These lasers are subject to stringent requirements in general, but even more so in ultra-long-haul links, where the fiber propagation highly emphasizes any non-ideality that the optical sources might have.
This invention presents a novel approach to collaborative laser phase noise correction in multicarrier transmission systems by being able to separate the contributions of each of the lasers in the system, thus being able to correct more accurately the affecting phase noise in each subcarrier. This is achieved through the usage of two reference subcarriers. In addition to phase noise correction, this invention allows for inline digital monitoring of the systems lasers independently, to identify and counteract on faulty lasers, being a huge advantage for modern day flexible transmission systems.
