论文标题
远程水上的窃听相匹配的跨空面
Remote Water-to-air Eavesdropping through Phase-Engineered Impedance Matching Metasurfaces
论文作者
论文摘要
从空气中远程接收水下声音是一项长期的挑战，这在水上接口处的大型阻抗不匹配阻碍了声音。在这里，我们介绍并通过实验证明了一种通过相匹配的跨膜的远程有效水窃听技术的技术。通过明智地设计超薄的机械边界，我们使水上接口具有听觉透明，与此同时，我们能够对传输的波前进行模式，从而有效地控制遥远的空气传感器的有效空间位置，从而可以测量具有较大信号到物理范围的较大信号范围，如果将其近距离地延伸到近处，则可以测量较大的信号。实验证明了这种空气传播的水下声音，其灵敏度增强超过了8 kHz时的38 dB。我们进一步展示了轨道 - 角摩肌 - 摩尔多克体通信和水下声学通信的机会。我们的元表面为通信和传感开辟了新的途径，这些途径可以转化为纳米镜和射频。
Efficiently receiving underwater sound remotely from air is a long-standing challenge in acoustics hindered by the large impedance mismatch at the water-air interface. Here we introduce and experimentally demonstrate a technique for remote and efficient water-to-air eavesdropping through phase-engineered impedance matching metasurfaces. By judiciously engineering an ultrathin mechanically-rigid boundary, we make the water-air interface acoustically transparent and at the same time we are able to pattern the transmitted wavefront, enabling efficient control over the effective spatial location of a distant airborne sensor such that it can measure underwater signals with large signal-to-noise ratio as if placed close to the physical underwater source. Such airborne eavesdropping of underwater sound is experimentally demonstrated with a measured sensitivity enhancement exceeding 38 dB at 8 kHz. We further demonstrate opportunities for orbital-angular-momentum-multiplexed communications and underwater acoustic communications. Our metasurface opens new avenues for communication and sensing, which may be translated to nano-optics and radio-frequencies.
