Intensity and phase noise spectra in semiconductor lasers: a parallelism between the noise enhancing effects of pump blocking and nonlinear dispersion

The intensity and phase noise spectra of a single-mode semiconductor laser are derived on the basis of a set of equations which includes pump blocking and nonlinear dispersion, thus taking into account the dependence of (i) the pump rate and (ii) the refractive index on the carrier density in the active layer. As a consequence, the carrier fluctuations cause an increase in the low-frequency branch of the (i) intensity and (ii) phase noise spectra, respectively.