基于损耗/增益均衡双曲型异向介质的局域场非寻常极致增强方法研究

Aiming at high-performance, high compatibility and easy-to-fabricate requirements in current implementations and applications of local-field enhancement, transformation optics theory including complex-coordinate transformation optics as well as hyperbolic metamaterials with balance loss and gain are studied simultaneously in order to obtain the singular local-field enhancement. It is proposed to carry out this project from three aspects, namely transformation optics theory, hyperbolic metamaterials with balance loss and gain and optimization algorithm, so as to solve the problems such as complicated structures and limited enhancement factor due to the structure at the present stage. The purpose of this project is to reveal the influence mechanism induced by different coordinate transformations as well as the shape, size and interface of unit cells for the hyperbolic metamaterials with balance loss and gain. Therefore, the optimization model of singular local-field enhancement and the characterization system of hyperbolic metamaterials with balance loss and gain are established, on the basis of application-oriented on-chip optical technologies. As the results, by combining theoretical study and experimental verification, the structure-function integration design theory and method system aimed at applications will be developed, establishing the methodology foundation for the optimization design of local-field enhancement and providing a new avenue towards designing

本项目针对目前局域场增强在实现和应用中所面临的高性能、高兼容性、易实现等需求，开展基于复数坐标变换等变换光学理论与损耗/增益均衡双曲型异向介质相结合的局域场极致增强的研究。拟从变换光学理论、损耗/增益均衡双曲型异向介质设计和优化算法三个方面开展研究，解决现阶段局域场增强设计过程中遇到的诸如结构复杂、局域场增强因子受器件结构制约等迫切问题。通过本项目的研究，将揭示不同坐标变换与损耗/增益均衡双曲型异向介质单元结构的形状、尺寸、界面对局域场极致增强的影响机制，建立基于光学芯片应用导向的局域场极致增强优化模型和损耗/增益均衡双曲型异向介质的性能表征系统。本项目采用理论和实验相结合的研究方法，可望形成面向应用需求的结构-功能一体化设计理论与方法体系，为光子学领域设计光学器件提供了一个新的思路。

当前局域场增强面临性能、兼容和制备三个方面的制约，导致其难以进一步实现和应用。本项目的核心内容是研究变换光学理论与损耗/增益均衡双曲型异向介质相结合的局域场极致增强，拟从变换光学理论、损耗/增益均衡双曲型异向介质设计和优化算法三个方面开展研究。在本项目的开展中，我们将变换光学理论与双曲型异向介质的参数设计结合，利用变换光学理论设计具有反常色散的双曲型异向介质，进而提出宽频纳米成像的设计方法。这是局域场增强的其中一个应用。此外，我们提出了双曲等离激元在圆柱层状结构中的局域场增强设计，利用保角变换理论，能够有效地提高圆柱层状结构的设计，实现对双曲等离激元的聚焦。我们还深入地研究了双曲型异向介质中光轴调控对局域场增强的影响，所实现的局域场增强能够进一步应用到单光子源领域。同时，我们还利用机器学习等优化算法，提出智能隐身器件、智能超构表面等设计。本项目的预期目标已充分完成，也取得了重要进展，对局域场增强理论及应用具有重要的推动作用。