红外表面等离激元增强光热效应特性及其应用研究

The main obstacle limiting practical applications of surface plasmon polariton (SPP) components is huge losses due to absorption in metallic materials. The light is absorbed and converted into heat in SPP components, causing photothermal effect. However, if the photothermal effect can be utilized properly, it may pave the way for novel applications of SPP components in integrated photonic circuits, thermal infrared imaging, etc. This project aims at clarifying the physical mechanism of SPP-assisted photothermal effect, designing and fabricating sub-wavelength metallic components with high photothermal conversion efficiencies in infrared region, and exploring potential applications of new functional devices based on photothermal effect, such as thermo-optical modulation of optical waveguides, etc. The photothermal devices proposed in this project have advantages such as: high light absorption and thermal conversion efficiency, controllable absorption wavelength and bandwidth, nanoseconds response time, and subwavelength spatial response which breaks diffraction limit. The project is expected to expand and deepen the understanding of interaction between light and matter in the mesoscopic scale, and provide new ideas and means for applications of SPP components.

目前限制表面等离激元器件走向实用的主要障碍是金属材料对光的吸收损耗：光被吸收后转换成热量导致光热效应。然而，如果利用金属损耗带来的光热效应，就可以为表面等离激元器件在集成光电回路、热红外成像等领域提供新的应用空间。本项目将从理论和实验两方面入手，研究阐明表面等离激元增强光热效应的物理机制，设计并实验上制备在红外波段具有高光热吸收转化效率的亚波长金属器件，探索基于光热效应的新型功能器件的潜在应用，如光波导的热光调制等。项目所提出的基于光热效应的器件具有以下突出优点：光吸收及热转换效率高，吸收波长和带宽可控；时间响应可达到纳秒级；空间响应亚波长尺度，突破衍射极限。该项目有望拓展与深化对介观尺度光与物质相互作用规律的认识，为表面等离激元器件的应用提供新思路、新手段。

金属对光的吸收损耗效应，即光被吸收损耗并转化为热量产生的光热效应，严重限制基于表面等离激元(SPP)微纳光子器件的发展。本项目着重研究金属纳米结构的光热效应，为其广泛应用打下良好基础。研究内容包括：表面等离激元增强光热效应物理机制研究；光热功能器件特性及设计研究；光热器件制备和表征研究。项目在光热效应研究方面取得进展，在国际光学领域刊物上共发表SCI论文14篇。代表性研究成果包括：1. 亚波长周期性金属结构增强吸收效应； 2. 基于光热效应的纳米尺子；3. 用于光互联的表面等离激元波导光热特性研究；4. 基于金属纳米颗粒光热效应的空间温度分布调控；5. 基于光热效应的硅光电子开关。项目研究成果不仅有助于深入理解表面等离激元光热效应，而且为光热效应的扩展和应用打下了良好基础。