掺镱双包层高功率光纤激光器输出特性研究

对线形腔掺镱双包层高功率光纤激光器的输出特性进行了研究 ,通过求解速率方程 ,得到了激光器泵浦阈值功率、输出光功率和斜率效率的表达式。分析了光纤长度、腔镜反射率和泵浦波长等因素对激光器阈值功率、输出光功率和斜率效率的影响 ,为高功率光纤激光器的优化设计提供了理论依据     

谐波信号频率的混沌检测方法

该文针对实际中大量存在的未知谐波信号频率,提出用非线性混沌动力学系统检测的方法;先从非线性方程理论出发论证系统存在周期解;然后建立仿真模型,用定向过零技术计算谐波频率;经过对计算结果绝对误差与相对误差的分析,得出该项技术是可行的。同时提出在检测频率后,进一步检测谐波幅值的可能性。     

Physical mechanism of the chaotic detection of the unknown frequency of weak harmonic signal and effects of damping ratio on the detection results

In the zero-order approximation, we use the perturbation method of parameter with small magnitude to prove that the harmonic frequency in the solution of the equation is close to that of the driving force when the chaotic system from Duffing－Holmes equation stays in the stable periodic state, which is the physical mechanism of the detection of the unknown frequency of weak harmonic signal using the chaotic theory. The result of the simulation experiment shows that the method proposed in this paper, by which one can determine the frequency of the stable system from the number of circulation change of the phase state directionally across a fixed phase state point (x,\dot{x}) in fixed simulation time period, is successful. Analyzing the effects of the damping ratio on the chaotic detection result, one can see that for different frequency ranges it is necessary to carefully choose corresponding damping ratio α.     

纳伏级正弦信号的混沌检测方法研究

提出一种基于混沌理论的纳伏级正弦信号的测量方案，给出了对正弦信号进行混沌检测的原理与方法，仿真实验表明将该混沌检测系统与本文所设计的纳伏级正弦信号发生器相结合，在任何零均值色噪声背景下对微弱正弦信号的检测下限可降至nV级的水平。