REDUCTION OF OPTICAL BEAT INTERFERENCE IN SCM WDMA NETWORKS USING PSEUDORANDOM PHASE MODULATION

A new approach is suggested to reduce the optical beat interference (O BI) in subcarrier multiplexed (SCM) wavelength-division multiple acces s (WDMA) networks. The idea is to deliberately introduce independent r andom polarization fluctuations in the electric fiels transmitted on e ach optical channel. Random polarization results in an expanded OBI sp ectrum, and hence, less OBI power at the reference user receiving filt er output. Electro-optic phase modulation is used to introduce polariz ation randomness in the fiels before they are coupled into the fibers. A two-user system was simulated. Simulation results show the drastic reduction in OBI power spectral density using appropriate PN signals.