Theoretical analysis of mode partition noise in single-frequency semiconductor lasers

The effects of mode partition noise in signal transmission using single-frequency lasers and dispersive fibres are analysed theoretically. Our analysis shows that the effect of fibre dispersion can easily be taken into account by considering the mode suppression ratio being reduced by a factor √2. Our results also show that under certain circumstances a mode suppression ratio as low as 400 is tolerable (with a power penalty <0.1 dB), and mode partition noise in single-frequency lasers is probably not a major noise source for lightwave communications compared with other effects such as wavelength chirp.