采用周期矩形脉冲信号直接调制色噪声作用下的单模激光增益模型,运用线性近似的方法计算得到了模型输出光强的自关联函数和关联时间(Tc),并讨论了光强关联时间随噪声强度和调制脉冲信号的变化关系。研究结果发现:噪声关联程度λ<0时,光强关联时间Tc随噪声强度Q、D及脉冲信号的振幅A的变化曲线均出现了随机共振现象,系统的涨落达到最小,而在λ≥0时,Tc单调变化;在-1<λ<1范围内,Tc随噪声关联时间τ和信号的脉冲宽度θ的变化曲线也均出现了随机共振现象,且随λ的减小,共振现象越明显;Tc随信号周期T的变化却出现了抑制现象,λ越小,抑制作用越强。

Considering the gain-noise model of a single-mode laser system with colored noise modulated by periodic pulse signal, we calculate the autocorrelation functions and correlation time of output laser intensity by the means of linear approximation method, and discuss that the intensity correlation time (Tc) is changed with noise intensity and input signal. The results show that the phenomena of stochastic resonance are detected in the laser system by virtue of the curves of intensity correlation time versus intensities of the pump noise and quantum noise and pulse amplitude when cross-correlation coefficient (λ) is less than zero, the statistical fluctuation of laser system is minimum. If λ≥0 the intensity correlation time is monotonic. Moreover, in the range -1<λ<1, the phenomena of stochastic resonance are also detected in the curves of intensity correlation time versus noise correlation time and pulse width (θ), and with the decrease of λ, the resonance is increasing. There appears Inhibit phenomenon in the curve of intensity correlation time versus pulse period (T), and the inhibition is more obvious with the decrease of λ.