Del Hougne Philipp, Yeo K Brahima, Besnier Philippe, Davy Matthieu
Univ Rennes, CNRS, IETR - UMR 6164, F-35000, Rennes, France.
Phys Rev Lett. 2021 May 14;126(19):193903. doi: 10.1103/PhysRevLett.126.193903.
Wavefront shaping (WFS) has emerged as a powerful tool to control the propagation of diverse wave phenomena (light, sound, microwaves, etc.) in disordered matter for applications including imaging, communication, energy transfer, micromanipulation, and scattering anomalies. Nonetheless, in practice the necessary coherent control of multiple input channels remains a vexing problem. Here, we overcome this difficulty by doping the disordered medium with programmable meta-atoms in order to adapt it to an imposed arbitrary incoming wavefront. Besides lifting the need for carefully shaped incident wavefronts, our approach also unlocks new opportunities such as sequentially achieving different functionalities with the same arbitrary wavefront. We demonstrate our concept experimentally for electromagnetic waves using programmable metasurfaces in a chaotic cavity, with applications to focusing with the generalized Wigner-Smith operator as well as coherent perfect absorption. We expect our fundamentally new perspective on coherent wave control to facilitate the transition of intricate WFS protocols into real applications for various wave phenomena.
波前整形（WFS）已成为一种强大的工具，用于控制各种波现象（光、声、微波等）在无序介质中的传播，其应用包括成像、通信、能量传输、微操纵和散射异常。然而，在实际应用中，对多个输入通道进行必要的相干控制仍然是一个棘手的问题。在这里，我们通过在无序介质中掺杂可编程的超原子来克服这一困难，以便使其适应任意施加的入射波前。除了消除对精心塑造的入射波前的需求外，我们的方法还开启了新的机遇，例如使用相同的任意波前依次实现不同的功能。我们在一个混沌腔中使用可编程超表面对电磁波进行了实验验证，展示了我们的概念，其应用包括使用广义维格纳 - 史密斯算子进行聚焦以及相干完美吸收。我们期望我们对相干波控制的全新观点能够促进复杂的波前整形协议向各种波现象的实际应用的转变。
