近日，以色列理工学院的Guy Bartal及其研究团队取得一项新进展。经过不懈努力，他们使用直接反馈实现近场的动态控制和操纵。相关研究成果已于2024年10月24日在国际知名学术期刊《光：科学与应用》上发表。

该研究团队展示了通过实时近场成像提供的直接反馈，实现对纳米光子近场的主动控制。研究人员利用远场波前整形技术来控制表面波中的纳米光子图案，展示了以纳米级精度实现近场焦点的平移和分裂、不同近场角动量的主动切换，以及利用实时操作所提供的反馈来校正因结构缺陷而受损的图案。这种同时整形和观察纳米光子场的能力，可能对纳米级光学操控、集成量子发射器的光学寻址以及近场自适应光学等多种应用产生重大影响。

据悉，在纳米尺度上整形和控制电磁场对于推动光通信、传感和计量学中使用的高效紧凑型设备的发展至关重要，同时也有助于探索光与物质相互作用及光学非线性的基本特性。在这些努力中，对光进行主动控制的实时反馈可以带来显著优势，能够补偿不断变化的实验条件以及设备固有的或累积的缺陷。扫描近场显微镜本质上速度较慢，无法提供这种实时反馈，而迄今为止，只有基于散射的显微镜才能实现这一点。

附：英文原文

Title: Dynamic control and manipulation of near-fields using direct feedback

Author: Kher-Aldeen, Jacob, Cohen, Kobi, Lotan, Stav, Frischwasser, Kobi, Gjonaj, Bergin, Tsesses, Shai, Bartal, Guy

Issue&Volume: 2024-10-24

Abstract: Shaping and controlling electromagnetic fields at the nanoscale is vital for advancing efficient and compact devices used in optical communications, sensing and metrology, as well as for the exploration of fundamental properties of light-matter interaction and optical nonlinearity. Real-time feedback for active control over light can provide a significant advantage in these endeavors, compensating for ever-changing experimental conditions and inherent or accumulated device flaws. Scanning nearfield microscopy, being slow in essence, cannot provide such a real-time feedback that was thus far possible only by scattering-based microscopy. Here, we present active control over nanophotonic near-fields with direct feedback facilitated by real-time near-field imaging. We use far-field wavefront shaping to control nanophotonic patterns in surface waves, demonstrating translation and splitting of near-field focal spots at nanometer-scale precision, active toggling of different near-field angular momenta and correction of patterns damaged by structural defects using feedback enabled by the real-time operation. The ability to simultaneously shape and observe nanophotonic fields can significantly impact various applications such as nanoscale optical manipulation, optical addressing of integrated quantum emitters and near-field adaptive optics.

DOI: 10.1038/s41377-024-01610-2

Source: https://www.nature.com/articles/s41377-024-01610-2