Joint Study on nonlinear optics in nanostructured materials

纳米结构材料非线性光学联合研究

基本信息

批准号：
08044067
负责人：
NAKAMURA Arao
金额：
$ 2.94万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08044067/
关键词：
Metal nanocrystal glass composite Semiconductor nanocrystals Diluted magnetic semiconductors Laser ablation technique Pump and probe spectroscopy Nonlinear optical response Hot electrons レーザーアプレーション銀ナノ結晶半磁性半導体超微粒子非線形光学

项目摘要

We have studied nonlinear optical properties of nanostructured materials to investigate a guiding principle for development of photonic device materials. Exchanging the researchers in French and Japanese teams, we performed experiments and discussed to get mutual understanding of this study. In silver nanocrystal/glass composites, we investigated the nonlinear response in a femtosecond time region with different excitation conditions : surface plasmon, interband (Nagoya University) and intraband (Ecole polytechnique) excitations. we have found that the nonlinear response with a reponse time of a few ps is originated from hot electron effects and nonlinear refractive index is negative. For less than 200 fs, the electron system does not show the Fermi distribution because the system is not in equilibrium. Furthermore, we have observed oscillation behaviors in nonlinear response due to ballistic phonon scattering. In diluted magnetic semiconductors, we have succeeded to fabricate CdMnTe nanocrystals with a diameter of 12 nm by means of the laser ablation technique. In CuCl nanocrystals we have observed quantum beat phenomena due to the quantum interference between exciton and biexciton states and the interference between the zero-phonon and LO phonon assisted transition of confined excitons. Furthermore, we have observed, for the first time, the memory effect of the reservoir, ie. the non-Markovian phase relaxation of confined excitons since acoustic phonons are confined. Finally, we have found the the enhancement of third-order susceptibilities in copper halide nanocrystals is originated from the giant oscillator strength effect, and the two-exciton state and the multiexciton states due to the valence band structure play an important role in nonlinear susceptibilities at the exciton resonance in the large size region. These results give us a guiding principle to develop nonlinear optical materials on the nanometer scale.

我们研究了纳米结构材料的非线性光学性质，以研究用于开发光子设备材料的指导原理。通过法国和日本团队交换研究人员，我们进行了实验，并讨论了以获得对这项研究的相互了解。在银纳米晶/玻璃复合材料中，我们研究了具有不同激发条件的飞秒时间区域的非线性响应：表面等离子体，带（Nagoya University）和映射（Ecole Polytechnique）激发。我们发现，几个PS的回复时间的非线性响应起源于热电子效应，非线性折射率为负。对于小于200 fs，电子系统不会显示费米分布，因为该系统不处于平衡状态。此外，我们已经观察到由于弹道声子散射引起的非线性反应中的振荡行为。在稀释的磁性半导体中，我们成功地通过激光消融技术制造了直径为12 nm的CDMNTE纳米晶体。在CUCL纳米晶体中，由于激子和Biexciton状态之间的量子干扰以及零孔子和LO唱机辅助辅助过渡的量子干扰，我们观察到了量子Beat现象。此外，我们首次观察到了储层的记忆效应，即。由于声音子被限制，因此受限制激子的非马克维亚相松弛。最后，我们发现铜卤化物纳米晶体中三阶敏感性的增强起源于巨大的振荡器强度效应，由于价带结构在巨大尺寸区域的非线性敏感性中起着重要作用，因此价值带结构在非线性敏感性中起着重要作用。这些结果为我们提供了指导原则，可以在纳米尺度上开发非线性光学材料。