单模激光系统随机共振的模拟研究

摘要

Single-mode laser systems with modulated signals are studied by the method of numerical simulation. The signal-to-noise ratio, the output signal power, and the background noise power are analyzed near and far from the threshold. It is found that when the laser works near the threshold, the signal-to-noise ratio is present and the behavior of stochastic resonance takes place as the quantum noise increases, no matter whether the quantum noise is correlated with the pump noise. The correlation between the two noises, however, will increase the signal-to-noise ratio. And when the laser works far from the threshold, only when the two noises are correlated can the behavior of stochastic resonance appear. It is also found that the output signal power can be influenced by the noises. What is more, the simulation results are compared with those obtained by the method of linear approximation.%用数值模拟方法对具有调制信号的单模激光系统进行了研究，分析了在阈值附近和远离阈值两种工作方式下的输出信噪比、输出信号功率、背景噪声功率，并与线性化近似结果进行了对比．研究发现，激光在阈值附近工作时，输出信噪比会随着量子噪声的增大出现随机共振现象，这一现象不要求泵噪声与量子噪声存在关联，但噪声之间的关联会进一步增大信噪比；在远离阂值时，只有噪声间存在关联时才会发生随机共振现象．研究还发现噪声也会影响输出信号的功率．