脉冲序列调制色噪声作用下单模激光损失模型的随机共振  

Stochastic Resonance for a Loss-noise Model of the Single-mode Laser Driven by Colored Noise Modulated by Periodic Pulse Trains

作　　者：汪志云[1] 陈培杰[1] 张良英[1] 

机构地区：[1]湖北文理学院物理与电子工程学院,湖北襄阳441053

出　　处：《河北师范大学学报（自然科学版）》2012年第5期467-472,共6页Journal of Hebei Normal University：Natural Science

基　　金：国家自然科学基金(11045004)

摘　　要：运用线性近似的方法计算了周期矩形脉冲序列直接调制色噪声作用下的单模激光损失模型输出信号光强的自关联函数和关联时间,并讨论了光强关联时间随系统净增益系数a0、噪声关联时间τ和调制脉冲信号周期T和宽度θ的变化关系.研究结果发现:当系统的各参数及噪声强度取一定值时,Tc—a0,Tc—τ,Tc—θ和Tc—T曲线均出现了随机共振现象,并且Tc—a0和Tc—T曲线还出现了1个抑制谷;噪声关联系数λ的绝对值越小,共振曲线的共振峰越高,系统的共振现象更加明显;脉冲信号振幅A和抽运噪声强度P对系统共振曲线的影响基本相同,取值越小,共振现象越不明显,当小于某一值时,Tc随a0单调减小,Tc—a0曲线的共振现象消失;而量子噪声的强度Q越小,Tc—a0曲线的共振现象越明显,并且当Q大于某一值时,Tc—a0共振现象消失.By means of linear approximation method,the autocorrelation function and the correlation time of intensity of a single-mode laser driven by colored noise modulated and a periodic pulse trains were calculated,and the variance between the intensity correlation time（Tc） with net gain a0,noise correlation time,period（T）and width（θ） of pulse trains was analyzed.The results show that,when the parameters of the system and the noise intensities take certain values,the phenomena of stochastic resonance are detected in the laser system by virtue of the curves of Tc-a0,Tc-τ,Tc-θ and Tc-T,and the inhibit wells are found in curves of Tc-a0 and Tc-T.As the absolute value of cross-correlation coefficient λ decrease,the resonance peak increase,and resonance phenomenon of system is more remarkable.The influence of pulse amplitude A on the resonance is same as pump noise intensity P,as their values decrease,the resonance phenomenon is abate,Tc monotonically descends with increasing a0 and the resonance disappear when their values are less than a certain value.However,decreasing quantum noise intensity Q,resonance phenomenon of Tc-a0 curve is more remarkable,and the resonance disappears only when Q is more than a certain value.

关 键 词：周期脉冲序列 噪声 光强关联时间 随机共振 

分 类 号：O436[机械工程—光学工程]