Effect of side-mode suppression ratio on the performance of self-seeded gain-switched optical pulses in lightwave communications systems

The side-mode suppression ratio (SMSR) of self-seeded gain-switched optical pulses is shown to be an extremely important factor for the use of these pulses in optical communications systems. Experiments carried out involving pulse propagation through dispersion-shifted fiber and a bandpass optical filter demonstrate that, for SMSR values of less than 25 dB, the buildup of noise due to the mode partition effect may render these pulses unsuitable for use in optical communications systems.