Simulation and Optimization of Graphene Oxide Tunable Metalens

多焦点镜头是光通信、虚拟现实显示和显微镜的重要组成部分，但传统镜头的体积庞大严重阻碍了其广泛应用。得益于超表面前所未有的光调制能力，超透镜能够以更紧凑的占地面积提供多焦点功能。目前双焦点或多焦点超透镜已经实现，但它们大部分都是将多个单焦点超透镜基于复用的形式组合成一个多焦点超透镜，导致不可避免的串扰和较低的聚焦效率，而且不便于控制不同焦点之间的相对强度。因此，文章提出了一种拟利用激光直写氧化石墨烯材料实现可调多焦点超透镜。这种设计使超透镜能够产生多个焦点，同时保持与单焦点超透镜相当的捕获目标信息的能力。该方法在光学成像、光束整形、自适应光学等领域具有重要的应用潜力。Multi-focus lenses are an important part of optical communication, virtual reality display, and microscope, but the large size of traditional lenses seriously hinders its wide application. Thanks to the unprecedented light modulation capability of metasurfaces, metalens can provide multi-focus functionality in a more compact footprint. Currently, bifocal or multi-focus metalenses have been realized, but most of them combine multiple single-focus metalenses into multi-focus metalens based on multiplexing, resulting in inevitable crosstalk and low focusing efficiency, and it is not easy to control the relative intensity between different focal points. Therefore, in this paper, a tunable multi-focus metalens is proposed by using laser direct writing graphene oxide material. This design enables the metalens to generate multiple focal points while maintaining the ability to capture target information comparable to that of a single-focal metalens. This method has important potential for application in optical imaging, beam shaping, adaptive optics, and other fields.