基于能带异常色散的声光同步调控

在微纳尺度上同步操控光声，以实现光声集成调控及增强光声（力）耦合，已成为新的研究热点。当前的实现方式聚焦于在同一微结构中形成声光双重带隙，但对带隙的严重依赖会存在一些不能克服的缺陷。特殊的能带结构能产生异常色散，对光声可实现另类不同于基于带隙的高效调控。本项目拟首次探索通过调制带隙之外的能带结构实现光声的同步调控，这是一种新的对光声进行同步调控的物理机制。基于有限元法，通过探索恰当的微结构及光声参数，以构建光声相似的特殊能带结构，进而获得光声的同步异常色散。研究多类同步异常色散现象，包括负折射、自准直及超棱镜效应等。以此为基础，设计和实验验证集成光声功能的器件；研究光与声（或力）在微纳尺度上的增强耦合，包括受激布里渊散射及声光耦合效应，并探索其在光学技术领域的应用。本项目的研究可克服带隙应用的固有缺陷，不仅在学术研究方面具有重要科学意义，且在光声集成调控及光调制等方面具有广泛的应用前景。

It has become a new research hotspot to control simultaneously optical and acoustic waves at the micro and nano scale, realizing the integrated control of optical and acoustic waves as well as enhancing the acousto-optic (or opto-mechanical)coupling. The current methods mainly focus on constructing the coexistence of photonic and phononic band gaps in a same micro or nano structure, which exists some inherent deficiency due to the dependence of their characteristics on band gaps. From another point of view, a special energy band structure can form abnormal dispersion, thereby realizing another kind of efficient modification ways for simultaneously controlling optical and acoustic waves, which is different to the methods based on phoxonic band gaps. This project intends to explore the simultaneous control of optical and acoustic waves by modulating the energy band structure outside the band gaps. This is a new physical mechanism for simultaneously controlling optical and acoustic waves. Firstly, based on the finite element simulation method, similar special energy band structures for both light and sound can be formed by exploring appropriate structure, optical and acoustic parameters, then the simultaneous anomalous dispersion for light and sound would be achieved. We will study several kinds of synchronous anomalous dispersion phenomena, such as negative refraction, self-collimation and superprism effects, and so on. Based on those, we will design and experimentally verify various devices integrating optical and acoustic functions, study the enhanced coupling between light and sound (or force) at micro and nano scale, including stimulated Brillouin scattering and acousto-optic coupling effects, and explore their applications in the field of optical technology. The research of this project can conquer the inherent deficiency of the applications based on band gaps, thus not only has important scientific significance in academic research, but also has wide applications in integrated modification for both light and sound and optical modulation.