表面等离子体时空对称耦合腔系统中Fano共振的调控与传感研究

The miniaturization, multifunction, high integration and high performance are the inevitable development trend of photonic devices. Metallic nanoscale cavity-coupled waveguide provides a solution for high efficiency nanophotonic devices, while the intrinsic loss of metal is still the key issue for plasmonic devices. To solve this issue, the parity-time (PT) symmetry is creatively introduced, with which the unwanted loss can be converted into a necessary element for high-performance devices. By controlling the PT symmetry in propagation or transverse direction, we aim at investigating the realization, modulation and application of Fano resonance in the plasmonic coupled cavities. Utilizing a newly-established theoretical model and numerical simulation method, we will explore how the PT symmetry, transmission and sensing characteristics are determined and modulated by the systematic parameters such as gain, loss, resonance detuning, the profile of active-passive cavities, and then aim to achieve the Fano resonance responses with sharp slope, high extinction ratio, slow group velocity, small group velocity dispersion and dynamic tunability. In addition, we will try to discover the key role of PT symmetry in transmission dynamics and sensing properties in the plasmonic coupled cavities. The findings of this project will provide a new way and theoretical basis for the design of high performance, multiband and on-chip sensors.

小型化、多功能、高集成和高性能是光子器件发展的必然趋势。金属纳米腔耦合波导结构为新型高效率纳米光子器件的实现提供了方案，而金属损耗一直是表面等离子体光子器件研究的难题。基于时空(PT)对称效应能将制约器件性能的损耗转变为实现性能优越器件的必要因素，本项目拟通过垂直或平行于传播方向的PT对称调制，探讨表面等离子体耦合腔系统中Fano共振的实现、调控和应用。建立新的理论解析模型，运用数值模拟方法，探索表面等离子体耦合腔系统的PT对称性、光谱传输特性、传感特性与增益、损耗、共振失谐、有源/无源腔分布等参量之间的关系及其调控规律，实现高斜率、高消光比、低群速度、低群速度色散、动态调控的Fano共振效应，揭示PT对称性在光传输动力学过程及其传感特性中所扮演的关键角色。项目研究成果为高性能、多波段、芯片级传感器的研制提供新方法和理论基础。

小型化、多功能、高集成和高性能是光子器件发展的必然趋势。金属纳米腔耦合波导结构为新型高效率纳米光子器件的实现提供了方案，而其光谱特性及调控是实现性能优越器件的前提。本项目通过谐振模式及其相互作用的调制，探讨了表面等离子体耦合腔系统中Fano共振的实现、调控和应用。建立了新的理论解析模型，运用数值模拟方法，探索了表面等离子体耦合腔系统的光谱传输特性、传感特性与损耗、共振失谐、谐振腔分布等参量之间的关系及其调控规律，实现了高斜率、高消光比、低群速度、动态调控的Fano共振效应，揭示了其传感特性的重要影响因素。随着项目研究的不断推进，拓展了研究内容。基于非厄米奇异点附近的异常光学特性及光与物质的相互作用原理，探究了非厄米系统奇异点的相关理论，研究了超表面在单向传输，偏振控制，超灵敏传感等中的应用，阐明了奇异点在光学特性调控中所扮演的关键角色。项目研究成果将为高性能光子器件的研制提供新方法和理论基础。