共查询到15条相似文献,搜索用时 171 毫秒
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在周期力调制噪声驱动下单模激光系统的光强方程中加入调幅波, 用线性化近似方法计算了系统的光强关联函数和输出信噪比, 并对信噪比进行数值计算和分析, 发现低频调制频率Ω、高频载波频率ω和周期力频率Ωλ对系统的输出信噪比有很大的影响. 具体表现为信噪比R 随低频调制频率Ω 的变化过程中出现了多重随机共振和极强的单峰共振, 当Ω << ω 时, 系统出现的是多峰共振, 且随着Ωλ 增加, 共振峰间的距离增大, 峰值位置不变; 当Ω → ω 时, 输出信噪比R迅速增大, 而Ωλ 的影响被削弱甚至可以忽略, 多峰共振消失; 当Ω = ω 时, 系统出现了极强的单峰共振. 此外, 信噪比随周期力频率的变化呈现振幅减小的多重随机共振, 而随载流频率的变化出现单峰随机共振. 相似文献
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对单模激光增益模型的光强方程加入调频信号,用线性化近似方法计算了以δ函数形式关联的两白噪声驱动下光强的输出功率谱及信噪比. 结果表明,信噪比随抽运噪声和量子噪声强度的变化可出现典型随机共振,受调制信号振幅的影响,信噪比随载波信号频率和调制信号频率的变化出现抑制、单调上升、共振、抑制和共振等几种情况.
关键词:
抽运噪声
单模激光
随机共振
调频信号 相似文献
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在色噪声间的关联程度受时间周期调制的激光系统中,研究噪声受信号调制情况下的随机共振.用线性化近似的方法计算了光强关联函数及信噪比.具体讨论信噪比随噪声强度、噪声自关联时间、信号频率以及时间周期调制频率的变化关系.发现一种新的随机共振:信噪比随时间周期调制频率的变化出现周期振荡型随机共振;发现广义随机共振:信噪比随抽运噪声自关联时间的变化、随信号频率的变化出现随机共振;同时也存在典型的信噪比随噪声强度的变化而出现的随机共振.而信噪比随量子噪声自关联时间的变化表现为抑制.
关键词:
信号调制
时间周期调制
噪声间关联程度
周期振荡型随机共振 相似文献
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输入信号和噪声对单模激光随机共振的影响 总被引:3,自引:1,他引:2
采用色抽运噪声和实虚部间关联的量子噪声驱动的单模激光损失模型,运用线性化近似方法计算了周期性信号加性输入时激光系统的输出光强信噪比,发现用信噪比与量子噪声实虚部间关联系数的关系曲线描述的随机共振现象.在抽运噪声自关联为短时关联情况下,当信号振幅增大和频率增快、抽运噪声色关联时间增大时,系统的随机共振加强;而噪声强度的增加会削弱系统的随机共振.在抽运噪声自关联为长时关联情况下,当信号振幅增大和量子噪声强度减弱时,系统的随机共振加强;而信号频率、抽运噪声强度、抽运噪声色关联时间的变化对系统随机共振的影响很小. 相似文献
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Stochastic resonance in a single-mode laser driven by frequency modulated signal and coloured noises 下载免费PDF全文
By adding frequency modulated signals to the intensity equation of
gain--noise model of the single-mode laser driven by two coloured
noises which are correlated, this paper uses the linear
approximation method to calculate the power spectrum and
signal-to-noise ratio (SNR) of the laser intensity. The results show
that the SNR appears typical stochastic resonance with the variation
of intensity of the pump noise and quantum noise. As the amplitude
of a modulated signal has effects on the SNR, it shows suppression,
monotone increasing, stochastic resonance, and multiple stochastic
resonance with the variation of the frequency of a carrier signal
and modulated signal. 相似文献
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Stochastic resonance (SR) for bias signal modulation is studied in a single-mode laser system. By investigating a gain-noise model driven by correlated pump noise and quantum noise, we find that, whether the correlation coefficient between both the noises is positive or negative, SR always appears in the dependence of signal-to-noise ratio (SNR) upon the noise correlation time and the frequency of the modulation signal. However, only when the correlation coefficient between both noises is negative can SR occur in the dependence of SNR upon the quantum noise intensity and pump noise intensity, while when the correlation coefficient between both noises is positive, it shows monotonically. 相似文献
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针对由加性、乘性噪声和周期信号共同作用的线性过阻尼系统, 在噪声交叉关联强度受到时间周期调制的情况下,利用随机平均法推导了系统响应的信噪比的解析表达式. 研究发现这类系统比噪声间互不相关或噪声交叉关联强度为常数的线性系统具有更丰富的动力学特性, 系统响应的信噪比随交叉关联调制频率的变化出现周期振荡型随机共振, 噪声的交叉关联参数导致随机共振现象的多样化.噪声交叉关联强度的时间周期调制的引入有利于提高对微弱周期信号检测的灵敏度和实现对周期信号的频率估计.
关键词:
随机共振
周期振荡型共振
噪声交叉关联强度
信噪比 相似文献
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A linear system driven by correlated asymmetric dichotomous noises and periodic signal was investigated in the overdamped
case. The exact expressions of output signal amplitude and signal-to-noise ratio (SNR) of the system were derived. By means
of numerical calculations, we found that: (i) At some fixed multiplicative noise intensities, the output signal amplitude
with frequency exhibits the structure of a weak peak, even no peak as the dichotomous noise is asymmetric; (ii) In the case
of asymmetric dichotomous noise, the signal frequency can cause non-monotonous behavior of the output signal amplitude with
respect to multiplicative noise intensity; (iii) The curve of SNR with frequency has a weak peak and a trough in the case
of symmetric dichotomous noise, but no peak with asymmetric; (iv) Whether the multiplicative noise is symmetric or asymmetric,
the noise can enhance response of the system; (v) The SNR increases with the correlation strength between the two noises decreasing.
In addition, the plane of multiplicative noise intensity versus noise symmetric parameter was plotted. 相似文献