Influence of nonlinear gain and nonradiative recombination on the quantum noise in InGaAsP semiconductor lasers

Effects of nonlinear gain and nonradiative recombination on characteristics of intensity and phase noises of InGaAsP lasers emitting in a wavelength of 1.55 mum are investigated. The investigations are performed based on a self consistent numerical approach that takes into account the cross correlation of fluctuations among the injected electron number, photon number and the optical phase. Time variations of the fluctuations of the intensity and the shift of the lasing frequency are statistically analyzed. The corresponding frequency dependencies of intensity and frequency noises are characterized. The results show that both intensity and frequency noises around the relaxation frequency are suppressed when counting the nonlinear gain in the rate equations. The intensity noise is enhanced in the low frequency regime by increasing the nonradiative recombination. The results fit well with those predicted by the small-signal analysis.