厚介质情况下激光“热像”的演化规律分析  

Analysis of the evolvement of hot-image in case of thick nonlinear medium

作　　者：彭涛[1] 赵建林[1] 谢良平[1] 叶知隽[1] 李强[2] 粟敬钦[2] 

机构地区：[1]西北工业大学理学院光信息技术研究所,陕西省光信息技术重点实验室,西安710072 [2]中国工程物理研究院激光聚变研究中心,绵阳621900

出　　处：《物理学报》2007年第6期3255-3260,共6页Acta Physica Sinica

基　　金：国家自然科学基金委员会与中国工程物理研究院联合基金(批准号:10576023)资助的课题~~

摘　　要：以“热像”形成的衍射理论模型和分步傅里叶算法为基础,模拟研究了厚介质情况下“热像”的形成特点.重点分析了散射点调制系数(包括振幅调制和相位调制)、散射点与介质前表面之间的距离、散射点大小、入射光强等参数的变化对“热像”点位置以及强度的影响.数值模拟结果与解析理论结果进行了对比,在散射点调制系数和入射光强的变化对“热像”的影响两种情况下,得出了与解析理论基本一致的结论;在散射点大小的变化对“热像”的影响情况下,得出了与解析理论预言不同的结论.此外,还发现散射点与介质前表面距离为零时,在介质后表面也可能出现“热像”效应.Based on the split-step-Fourier-transform and the diffraction theory of hot-image model we made the simulation of the evolvement of hot-image in case of thick nonlinear medium. The changes of some parameters influencing the intensity and location of hot-image, such as the modulation coefficient （including amplitude modulation and phase modulation）, the distance between scatterer and the front surface of nonlinear medium, the size of the scatterer, the intensity of incident beams and so on, were detailedly analysed respectively. Numerical results were found to be in agreement with analytical theory for the changes in modulation coefficient and the intensity of incident beams, but not in agreement with analytical theory for the changes in the size of the scatterer. Moreover, when the distance between scatterer and the front surface of nonlinear medium is zero, hot-image will also be found on the back surface of nonlinear medium.

关 键 词：热像 小尺度自聚焦 分步傅里叶算法 散射点 

分 类 号：TN241[电子电信—物理电子学]