飞秒激励各向异性随机介质辐射脉冲的时域特性研究

Temporal Properties of Anisotropic Random Laser Emission Pulse Under Femtosecond Laser Excitation

基于随机激光的时域理论,利用高斯型函数描述飞秒脉冲的作用过程,研究飞秒脉冲激励下各向异性二维无序增益介质的辐射特性,并重点讨论了介质的尺寸、表面填充率和散射颗粒半径对辐射脉冲时域特性的影响,包括辐射脉冲的强度、延迟时间和脉冲宽度三个方面。结果表明,辐射光脉冲的时域特性与系统参数有关,通过改变上述三个参数可以控制辐射光脉冲的时域波形。数值模拟结果为研究超短脉冲激励各向异性随机激光的应用,特别是输出脉冲的时域波形可控性方面提供了理论依据。

Based on the time-dependent theory,the emission property of two-dimensional anisotropic random laser under femtosecond laser pumping is theoretically investigated by using a Gaussian function to describe the pumping process.The temporal properties of the random laser emission including the peak intensity,delay time and pulse width,are traced with the variation of the sample size,surface filling-fraction and radius of the scatterer.The results show that the behavior of random lasing depends strongly on the system parameters,one can control the output waveshape through modify the above three parameters.The present work can offer more theoretical guidance for the application of the anisotropic random laser,especially the controllability of output waveshape.