Meta-fiber optics - structuring light via 3D nano-printed meta-optics on designer multi-element fibers

光的紧密聚焦在许多应用中起着至关重要的作用，对于光学捕获和激光扫描显微镜非常重要。在这里，普通显微镜显示出诸如缺乏灵活性和可集成性、受限的波前控制和差的远程操作能力等局限性。迄今为止，还没有可靠的解决方案能够将灵活、稳健和远程的光传输/收集与强聚焦相结合。具有单模（SM）芯的光纤允许灵活和受控的光传输，同时由于输出光束的发散而显示出关于聚焦的限制。已经进行了纳米和微结构光纤端面的尝试，然而，其还没有达到超过0.7的数值孔径（NA）。元表面是光子器件，允许完全的波前控制。在纤维尖端上创建超表面已经被暂时解决，而在高NA下的强聚焦没有实现。最近，申请人已经表明，具有高达0.88的NA的3D纳米打印的超透镜可以与SM纤维接合。聚焦能力已经通过首次用一根SM纤维捕获微珠和细菌而得到证明。这些结果表明，结合纳米印刷超透镜与SM光纤产生一种新型的平台-超光纤平台-衍射限制远程光focusing.The项目的想法是调查的超光纤概念的光/物质相互作用，并证明其能力在一系列应用相关的实验。具体而言，该项目旨在设计3D纳米打印的超透镜，并将其与包括一个或多个SM芯和光束扩展部分的光纤连接。该项目包括光/物质相互作用的基础研究在这样一个系统考虑到光纤环境的特殊性。超纤维的实际相关性将通过光学捕获（动态和静态单点和多点捕获）和扫描显微镜（共焦和STED）来证明，旨在揭示超纤维是否允许通过单个紧凑型设备取代笨重的光学器件。总的来说，该项目将揭示超光纤的潜力，并导致一类新的集成，灵活和紧凑的光子器件，具有独特的远程光聚焦特性。

The tight focusing of light plays an essential role in many applications and is highly important for optical trapping and laser scanning microscopy. Here common microscopes show limitations such as a lack of flexibility and integrability, restricted wave front control and poor remote operating capabilities. Up to date no reliable solution exists that combines flexible, robust and remote delivery/collection of light with strong focusing.Optical fibers with single-mode (SM) cores allow for flexible and controlled transportation of light, while showing limitations regarding focusing due to the divergence of the output beam. Attempts to nano- and microstructure fiber end-faces have been undertaken which, however, have not reached numerical apertures (NAs) beyond 0.7. Meta-surfaces are ultrathin photonic devices and allow for complete wave front control. Creating meta-surfaces on fiber tips has tentatively been addressed while strong focusing at high NA was not achieved. Recently the applicants have shown that 3D nano-printed meta-lenses with NAs as high as 0.88 can be interfaced with SM fibers. The focusing capabilities have been demonstrated by trapping microbeads and bacteria with one SM fiber for the first time. These results suggest that combining nanoprinted meta-lenses with SM fibers yields a new type platform – the meta-fibers platform – for diffraction limited remote light focusing.The idea of this project is to investigate the light/matter interaction of the meta-fiber concept and demonstrate its capabilities in a series of application-relevant experiments. Specifically, the project aims for designing 3D nano-printed meta-lenses and interfacing them with optical fibers including one or more SM cores and beam expansion sections. The project includes fundamental studies of light/matter interaction in such a system taking into account the peculiarities of the fiber environment. The practical relevance of meta-fibers will be demonstrated by optical trapping (dynamic and static single- and multi-site trapping) and scanning microscopy (confocal and STED), aiming to reveal if meta-fibers allow to replace bulky optics by single compact devices. Overall this project will reveal the potential of meta-fibers and lead to a new class of integrated, flexible and compact photonic devices with unique properties regarding remote light focusing.