二维非线性光子晶体中宽带二阶级联效应的研究

项目名称： 二维非线性光子晶体中宽带二阶级联效应的研究

项目编号： No.11204206

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 王文杰

作者单位： 太原理工大学

项目金额： 25万元

中文摘要： 随着全光通信、超短脉冲频率变换技术的发展，超宽带可调谐频率变换技术在全光转换方面的应用日益重要。基于材料二阶非线性的级联效应是实现全光转换的一种有效手段。采用周期、准周期非线性光子晶体的准相位匹配技术可以大大提高频率转换的效率, 却很难实现宽带范围内频率变换的连续调谐性；研究表明在无序结构的非线性光子晶体中, 连续的频谱空间分布为宽带范围内多个频率变换提供了可能,然而频率变换过程中极低的转换效率限制了它的进一步应用。 本工作通过引入新的二维非线性光子晶体空间结构分布，即通过对结构分布周期性和无序性的有效结合和优化, 深入研究二维非线性光子晶体空间结构分布对宽带二阶级联效应产生的影响，如宽带级联三倍频效应、基于频率上转换和下转换的基频光偏振开关，建立起宽带有效的级联频率变换与晶体空间结构分布的理论模型，有效地实现频率变换过程中效率与带宽的平衡，为宽带可调谐光子器件的研究提供新的途径。

中文关键词： 非线性光子晶体；宽带二阶级联效应；准相位匹配；频率变换；

英文摘要： Broadband frequency conversion technique is critical for a variety of applications in all-optical conversion as the development of optical communications, ultra-short pulsed frequency conversion and so on. Nonlinear quadratic effect based on the second-order nonlinear susceptibility provides an effective way in the realization of all-optical conversion. By quasi-phase matching in periodic and quasi-periodic nonlinear photonic crystal, frequency conversion efficiency can be dramatically enhanced except with a limitation in broadband tunablity for multiple frequency conversions. While as the other side, it was showed that random nonlinear photonic crystals presented a large potential for simultaneously multiple frequency conversion with amounts of possession in continuous spectral space, but with pretty lower conversion efficiencies limited for further applications. In this work, we will demonstrate new spacial modulation schemes of second-order susceptibility in two dimensional nonlinear photonic crystals combining periodic and disordered optimization of nonlinear photonic structures. The dependence of cascading effects on the spacial distribution in nonlinear photonic crystals will be dramatically studied, as an example of detailed study of effectively broadband triplet frequency conversion and optical po

英文关键词： Nonlinear photonic crystal；Broadband quadratic cascading effect；Quasi-phase matching；Frequency conversion；