高掺杂半导体微结构在太赫兹波段表面等离体共振效应及其器件应用

The extraordinary transmission of electromagnetic waves through an array of subwavelength metallic holes has attracted great interest and many experimental and theoretical works have been devoted to this phenomenon because its potential applications in terahertz(THz) devices. Except for the surface plasmonic resonance effect of subwavelength metallic hole arrays, the extraordinary transmission of surface plasmonic waves in the THz spectral region has also been observed in semiconductors with high carrier densities. How to fabricate all-optical devices for THz wave by using the tunable properties of semiconductors in dielectric constant has be come the focus of many research works. This project will be devoted to the investigation of laser-induced THz surface plasmonic resonance effects and the applications in THz devices by using the finite-difference time-domain (FDTD) simulation and optical-pump THz-Probe technique. We will focus on the physical mechanisms of the extraordinary transmission of THz wave through hole arrays with embeded semiconductor quantum dots. The physical mechanism resposible for the transition from photonic crystal to surface plasmonic resonance effect will also be investigated. All-optical switching for THz wave with high efficiency under the excitation of pump light based on real-time fast spped and transmission from photonic crystal effect to surface plasmonic resonance effect will be explored.

电磁波经过金属亚波长周期孔阵列之后的异常透射现象引起了人们的广泛关注，为此国内外进行了大量的实验和理论研究探索表面等离子体波在太赫兹器件方面的潜在应用。除了金属周期孔阵列在太赫兹波段观察到离子体共振效应之外，具有高浓度载流子的半导体材料也观察到太赫兹表面等离子体波的透射增强效应。利用半导体材料的介电性质可调谐和可控制特性，如何制备全光的太赫兹器件逐渐成为人们关注的焦点和研究重点。本项目通过FDTD数值模拟和激光泵浦太赫兹探测实验技术研究激光诱导高掺杂半导体亚波长微结构的太赫兹表面等离子共振效应以及在太赫兹全光器件中的应用。研究高掺杂半导体量子点亚波长微结构中的太赫兹透射增强效应的物理原因，重点研究半导体量子点亚波长微结构从光子晶体效应到表面等离子共振变化的超快动力学过程，探索利用重掺杂半导体量子点这种实时可调控性质制备超快和高效率的太赫兹全光开关等器件。

摘要：电磁波经过亚波长微结构和量子点等微型结构后的异常传输效应在太赫兹器件研究中具有重要意义，通过亚波长孔阵列产生的局域表面等离子体效应在集成纳米光子学和微米光子学方面的应用备受关注。本项目从理论和实验两个方面研究了纳米颗粒以及亚波长微结构的表面等离子体效应引起的局域场增强现象和耦合共振效应，得到了共振模式对于结构参数的依赖关系以及与表面等离子体共振相关的太赫兹器件效应；同时利用飞秒激光诱导产生碳量子点，通过调整飞秒脉冲的合适参数可控产生了碳量子阵列结构,讨论了碳量子的独特吸收和辐射等特性，这些结果对于基于表面等离子体共振的太赫兹器件制备以及应用方面具有一定意义。