IMPROVED METHOD AND APPARATUS FOR TRANSMITTING MULTIPLE CHANNELS IN A WAVELENGTH DIVISION MULTIPLEXED (WDM) OPTICAL COMMUNICATION SYSTEM WITH REDUCED RAMAN CROSSTALK AND NONLINEARDISTORTIONS

摘要

An improved method and apparatus is provided for transmitting a WDM opticalsignal. The method begins bymodulating optical channels that are each located at a different wavelengthfrom one another with (1) a respective one of aplurali-ty of information-bearing electrical signals that all embody the samebroadcast information; (2) a respective one of a plurality ofRF signals having a common functional broadcast waveform, at least one of theRF signals being out of phase with respect tore-maining ones of the plurality of RF signal and (3) at least one of the RFsignals being phase adjusted with respect to its originalphase. Each of the modulated optical channels is multiplexed to form a WDMoptical signal. The WDM optical signal, whilemaintaining the pre-assigned phase relationships between the modulationsignals of the optical channels, is forwarded onto anop-tical transmission path.