A frequency calibration method for multilocation optical FDM networks

A simple laser frequency calibration method is proposed for optical frequency-division-multiplexing communications networks where users are at remote locations. We calibrate the frequency of a transmitter laser by tuning it to a resonant peak of a Fabry-Perot etalon and determining the mode number of the resonant peak. We use a distributed frequency reference and a local Fabry-Perot etalon whose cavity length is slightly changed during the measurement. This method provides a high measurement accuracy with a cavity length change of less than 5%.<
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