光在二维无序介质中的动态传播过程

用有限时域差分 FDTD 法研究了光在二维无序介质中的动态传播过程.数值模拟了某一高斯脉冲光束入射到无序介质中光场的空间分布随时间的演化,结果表明：在光束入射的初期,能量从光源区向外传播并出现了清晰的波前传播的特点；经过一定的时间后,有部分能量从光源区向外扩散,而大部分能量逐渐聚集在介质中的一些小区域内,这与整体散射模型关于无序介质中光子局域化的研究相吻合,而且更清晰地呈现了形成光子局域化过程中的物理现象及整体散射干涉效应的重要机理作用.

Dynamical Propagation Process of Light in 2-D Random Mediums

The dynamical propagation process of light wave in two-dimensional random mediums was investigated using the finite difference time domain method.When a Gauss pulsed beam was introduced in a random medium,the spatial distributions of light wave in different time were simulated.The results show that when the propagation time is short,energy of the light is propagated out from the source and it propagates like a wave-front clearly.When the propagation time is getting longer,there are some energy keep diffusing out from the source,but a majority of energy is trapped in some regions of the medium step by step.It shows that with scattering time getting long the light is going to be localized in the random medium step by step.The results are coincident with the study of photon-localization base on the holistic scattering effect model in random mediums.