基于非线性切伦科夫辐射产生中红外超短脉冲机理与实验研究

项目名称： 基于非线性切伦科夫辐射产生中红外超短脉冲机理与实验研究

项目编号： No.11274224

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 曾祥龙

作者单位： 上海大学

项目金额： 90万元

中文摘要： 本项目研究基于光学切伦科夫辐射机理的一种新型非线性频率变换技术，旨在利用目前可获得的长脉冲激光输出，实现中红外波长超短脉冲输出的简单而有效的新方法。本项目探索的中红外波段超短脉冲产生及与物质相互作用，已经成为现代科学的重要研究前沿领域，具有很强的基础性与创新性。研究内容包括在非线性晶体和半导体材料的正常色散区获得周期量级超短脉冲孤子压缩过程，通过非线性光学切伦科夫辐射在反常色散区实现中红外超短脉冲产生，研究切伦科夫辐射的产生机理与实验验证；通过对飞秒脉冲在非线性介质的非线性传输模型精确模拟，获得中红外脉冲产生条件、输出效率优化和利用准位相匹配结构开展可调谐中红外波段（2－5um）飞秒激光脉冲产生、放大与压缩的新方法；基于稳定性高的光纤激光器作为泵浦，利用非线性切伦科夫辐射产生中红外超短脉冲，探索实现高效非线性频率转换的一个新途径。

中文关键词： 光学切伦科夫辐射；非线性频率转换；孤子隧道效应；色散波；中红外脉冲

英文摘要： We propose in this project a new nonlinear frequency conversion through optical Cherenkov radiation to produce the energetic ultra-short mid-IR pulses by pumping the available long pulsed laser output in the nonlinear media. The advantage of this approach is quite simple but powerful. The generation of ultra-short mid-IR radiation and its interaction with the nonlinear crystals and semiconductors has been the important research hot because of the fundamental and creative motivation. We will investigate the soliton compression of few-cycle pulses in the normal dispersion regime of the nonlinear second-order crystals and semiconductors and the mechanism of optical Cherenkov radiation and the experiments of achieving the ultra-short mid-IR pulses. We will also present the comprehensive model for the description of femtosecond pulses propagating in the nonlinear media and the phase-matching requirement for mid-IR generation and the optimization of the output efficiency of the optical Cherenkov radiation and the wavelength tuning（2－5 um）via quasi-phase-matching structure as well. The amplification and the compression of mid-IR generation are also considered. Finally we will focus on this approach to realize the nonlinear frequency conversion to mid-IR ultra-short pulses based on the optical Cherenkov radiation by usi

英文关键词： Optical Cherenkov radiation；nonlinear frequency；soliton tunelling effect；dispersive wave；mid-infrared pulse