Stochastic resonance in a gain--noise model of a single-mode laser driven by pump noise and quantum noise with cross-correlation between real and imaginary parts under direct signal modulation

Stochastic resonance (SR) is studied in a gain--noise model of asingle-mode laser driven by a coloured pump noise and a quantum noisewith cross-correlation between real and imaginary parts under adirect signal modulation. By using a linear approximation method, wefind that the SR appears during the variation of signal-to-noiseratio (SNR) separately with the pump noise self-correlation timetau , the noise correlation coefficient between the real part andthe imaginary part of the quantum noise lambda_q , theattenuation coefficient gamma and the deterministic steady-stateintensity I_0 . In addition, it is found that the SR can becharacterized not only by the dependence of SNR on the noisevariables of tau and lambda_q, but also by thedependence of SNR on the laser system variables of gamma and I₀. Thus our investigation extends the characteristic quantity of SRproposed before.