Increase in laser RIN due to asymmetric nonlinear gain, fiber dispersion, and modulation

It is shown that the low-frequency relative-intensity-noise (RIN) spectra of a Fabry-Perot laser are adequately described only when the effects of longitudinal mode coupling through the asymmetric nonlinear gain are accounted for. Additionally, for the first time, the authors have included this asymmetric mode coupling to accurately model the translation of the low-frequency noise of a semiconductor laser in the presence of modulation and fiber dispersion. The translation of noise, which determines the signal-to-noise performance in subcarrier multiplexed systems, is also confirmed experimentally.>