Suppression of interferometric noise in externally modulated lightwave AM-CATV systems by phase modulation
Multiple discrete reflections and Rayleigh scattering in a fibre network cause interterometric intensity noise, which degrades the carrier to noise ratio in AM-CATV systems, depending on the laser linewidth and length of the fibre section. This noise can be suppressed by up to 10 dB if single tone phase modulation of the optical signal is applied.