基于非线性参量上转换过程的表面等离激元激发研究

Surface plasmon polariton (SPP) that connect the properties of electron and photon has important applications in the field of micro/nano photonics. Because of its strong local effect and near-field enhancement property, SPP is an important means to break the optical diffraction limit and enhance the interaction between light and matter. In recent years, the excitation and modulation of SPP have attracted a lot of attention, but they are also one of the difficult research fields. This project proposes a new scheme of exciting SPP using the parametric up-conversion process in nonlinear media, and to study the new way of using SPP enhancement property to enhance the nonlinear conversion efficiency in medium. The nonlinear interactions between SPP and photon are systematically studied, and the composite structures of nonlinear medium and metal are designed to realize the effective modulation of SPP and nonlinear process. Through the research of this topic, the excitation of SPP with shorter-wavelength can be realized and have important application value in the fields of super-resolution imaging and new efficient frequency conversion mechanism.

连接电子和光子特性的表面等离激元（SPP）在微纳光子学领域具有重要的应用价值。因其具有很强的局域效应和近场增强的特性，是突破光学衍射极限、增强光与物质相互作用的重要手段。表面等离激元的激发和调控是近年来的研究热点，但同时也是研究难点之一。本课题提出一种在非线性介质中利用参量上转换过程激发表面等离激元的新方案，并研究利用表面等离激元对介质中非线性过程的增强作用提高非线性转换效率的新途径。系统研究表面等离激元与光子的非线性相互作用，同时设计非线性介质与金属的复合结构，实现对表面等离激元以及非线性过程的有效调控。通过本课题的研究，可以实现更短波长的表面等离激元激发，增强非线性过程的转换效率，在超分辨成像、新型高效频率转换机制等研究领域均有重要的应用价值。

利用参量上转换过程实现表面等离激元的激发及调控对于进一步拓展其应用范围十分重要。项目系统研究并建立了非线性界面上表面等离激元的激发过程的理论模型，对非线性界面上的非线性过程进行了系统的分析，并在实验上验证了非线性极化波辐射非线性谐波的过程。开展了非线性光子晶体与金属界面上表面等离激元的激发及调控研究，建立了周期极化结构对非线性谐波的调控理论，实验上验证了由于非线性极化结构产生不同阶数非线性谐波的过程。研究了低相干光非线性频率转换、参量放大等非线性过程及传输放大、束匀滑过程，对低相干光统计特性有了系统的认知，为进一步深化非线性过程激发表面等离激元的研究奠定了基础。