权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Wave phenomena in nonlinear disordered optical media

非线性无序光学介质中的波动现象

基本信息

批准号：
11640373
负责人：
TOMITA Makoto
金额：
$ 2.3万
依托单位：
Shizuoka university
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

We investigated both experimentally and theoretically the wave phenomena in nonlinear disordered optical media.[1] Two-beam pump-probe method in space and time domainsWe proposed and theoretically analyzed a new method of two-beam pump-probe method in space and time domains. As a result, besides the signal term, which reflects the temporal and spatial response of material, we found parametric coupling phenomena that suggest that two laser beams injected onto the nonlinear disordered optical media are coupled through the fluctuation effect.[2] Stimulated emission and absorption in disordered mediumWe applied the above new technique to investigate the gain volume of random laser. In this experiment, two excitation laser beams just below the threshold of the random laser were injected on the disordered medium and the spectral width of the luminescence was monitor as a function of the spatial distance of two beams. We experimentally found that the gain volume is relevant to the transport mean free path and the absorption length and the volume is uniquely represented using an equation which includes these parameters. The computer simulation was also performed and the simulation well explains the experimental results.[3] Observation of the memory effect by using the parametric coupling phenomenaWe examined the memory effect, which means that waves in disordered medium still retain the information on the wavefront, using the above parametric coupling phenomena. We have clearly demonstrated the coupling phenomena by a series of detailed experiments on LiNbO3 as the nonlinear disordered medium.

我们从实验和理论上研究了非线性无序光学介质中的波动现象。[1]提出了一种新的时空域双光束泵浦探测方法，并从理论上进行了分析。结果表明，除了反映材料时空响应的信号项外，还发现了参量耦合现象，表明两束激光注入到非线性无序光学介质中是通过涨落效应耦合的。[2]无序介质中的受激辐射和吸收我们应用上述新技术研究了无序激光的增益体积。在这个实验中，两个激发激光束刚好低于随机激光的阈值注入到无序介质上，并且监测发光的光谱宽度作为两个光束的空间距离的函数。实验发现，增益体积与输运平均自由程和吸收长度有关，增益体积可以用包含这些参数的方程唯一地表示。并进行了计算机模拟，模拟结果很好地解释了实验结果。[3]利用参量耦合现象观察波的记忆效应利用上述参量耦合现象，我们研究了无序介质中的波仍然保留波前信息的记忆效应。我们已经清楚地证明了耦合现象的一系列详细的实验LiNbO3作为非线性无序介质。