Solitons in fibre lasers and mode-locked systems

Soliton propagation in a laser fibre is investigated using multiple-scale perturbation analysis. The perturbative terms are linear loss and saturable nonlinear gain. Furthermore, we show the possibility of stable soliton-like propagation in an amplitude pulse mode-locked system consisting of a semiconductor laser coupled to a nonlinear fibre through a centre mirror. The soliton-like pulse is slightly asymmetric due to asymmetric gain amplification in the semiconductor laser.     

多频率小波

通过方向多分辨分析把由一个函数生成的多频率小波推广到由有限个函数生成的多频率小波，给出由函数φ1,…，φn，…ψn(2^j1 ^j2-1)的平移生成Vj(1)空间的Riesz基的充分必要条件，同时给出该小波的分解式。     

Gas lasers

Zeitschrift für angewandte Mathematik und Physik -     

基于CEEMDAN-MR-PE-NLE多频优化组合模型的碳金融市场价格预测

鉴于碳金融市场价格预测的复杂性,遵循"分解"、"重构"、"预测"、"集成"的总体建模架构,构建了CEEMDAN-MR-PE-NLE多频优化组合预测模型.先基于CEEMDAN算法对原始碳价序列进行分解,然后采用CCI贡献度指数和E-C进化聚类算法以及Lempel-Ziv复杂度指数对分量进行重构,进而得到高频分量、低频分量和趋势分量,利用PSO-ELM粒子群优化的极限学习机预测模型对三个重构分量分别进行预测,最后采用非线性集成算法将重构分量的预测结果进行集成,得到最终的碳价预测结果.五种模型预测效果评价指标和MCS检验均表明:与基准模型相比,构建的预测模型性能最优,DM稳健性检验结果也进一步证实了构建的预测模型的稳健性.     

Chemical lasers II

A short survey is given of population inversions resulting from chemical reactions. The way in which the possibilities for realisation of a chemical laser are investigated by us is discussed and the results obtained are given.     

Chemical lasers I

The concept of a chemical laser is discussed and a preferable definition is proposed. In order to obtain some insight into the feasibility of chemical pumping in general and into the orders of magnitude of the parameters involved, the consequences of a simple model, more or less related to a stationary flamelaser, are explored.According to this model i) a lower limit depending on flow velocity and wavelength exists for the rate at which production and radiative processes may proceed, and ii) the available gain can very appreciably exceed the critical value needed for laser action if certain conditions are satisfied.The assumptions underlying the model and its results, and their applicability in practice are briefly discussed.     

Boundedness of outputs of a class of lasers

In this note, a large class of lasers, represented by planar nonlinear ordinary differential equations known as the rate equations, is considered. It is shown that the outputs of the lasers are bounded when bounded inputs (currents) are applied to them.