Ambichl Philipp, Brandstötter Andre, Böhm Julian, Kühmayer Matthias, Kuhl Ulrich, Rotter Stefan
Institute for Theoretical Physics, Vienna University of Technology (TU Wien), A-1040 Vienna, Austria, EU.
Université Côte d'Azur, CNRS, LPMC, 06108 Nice, France, EU.
Phys Rev Lett. 2017 Jul 21;119(3):033903. doi: 10.1103/PhysRevLett.119.033903. Epub 2017 Jul 18.
We introduce a wave front shaping protocol for focusing inside disordered media based on a generalization of the established Wigner-Smith time-delay operator. The key ingredient for our approach is the scattering (or transmission) matrix of the medium and its derivative with respect to the position of the target one aims to focus on. A specific experimental realization in the microwave regime is presented showing that the eigenstates of a corresponding operator are sorted by their focusing strength-ranging from strongly focusing on the designated target to completely bypassing it. Our protocol works without optimization or phase conjugation and we expect it to be particularly attractive for optical imaging in disordered media.
我们基于已确立的维格纳-史密斯时延算子的推广，引入了一种用于在无序介质内部聚焦的波前整形协议。我们方法的关键要素是介质的散射（或传输）矩阵及其相对于目标位置的导数，目标位置即为人们想要聚焦的位置。文中给出了微波频段下的一个具体实验实现，结果表明相应算子的本征态按其聚焦强度排序——从强烈聚焦于指定目标到完全绕过该目标。我们的协议无需优化或相位共轭即可工作，并且我们预计它对于无序介质中的光学成像将特别有吸引力。
