二维随机介质中准态模的频谱时间演化特性

采用时域有限差分法数值求解Maxwell方程组，分析了平面随机介质中光波模式的频谱时间演化特性.随机介质的特征可以用散射颗粒的随机构形、介质参数（如颗粒的尺寸和填充率等）以及介质形态等因素来描述.这些因素决定了随机介质在准稳态下模式的频率特性与数量，但具有不同因素的随机介质中模式的产生、选择与演化，具有大致相同的特征与速度.平面随机介质的这些冷腔特性，与传统光腔中模式的产生、选择和演化的特征非常相似. 关键词： 激光物理 随机激光器 无序介质中的光学特性

Spectral time evolution of quasistate modes in two-dimensional random media

The spectral time evolution of optical modes in planar random media is analyzed by using the finite difference time domain method to numerically solve Maxwell equations. The character of random media can be described by some factors, including the random constitution of scattering particles, medium parameters (such as the surface-filling fraction and the size of particle), and the shape of me dium. Such factors determine the frequency property and number of optical modes in random medium under quasi-stable state. However, the media with different f actors have approximately the same character and rate for the generation, sele ction and evolution of optical modes. Such cold cavity properties of planar rand om media are similar to that in conventional optical cavities.