With the development of ocean research, communications from the air to underwater (e.g., aircraft to submarines) are especially important. However, the existing communication methods have their own limitations and wireless communication between underwater and the air has remained an unsolved problem. In this article, we propose a photoacoustic communication based on low-cost passive relays, which is capable of not only minimizing the energy loss both in water and in the air-water interface, but also relieving the difficulty of target seeking. Thus, we can get a six order of magnitude reduction of laser energy (25 J vs. 27 μJ) using passive relays whose cost is less than US$1.00. It is also demonstrated that our photoacoustic communication can work decently under complex water situations including waving and pollution. This creationary photoacoustic application may become a practical way to communicate from the air to underwater.

中文翻译：

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基于低成本无源继电器的从空中到水下的光声通信

随着海洋研究的发展，从空中到水下（例如，飞机到潜艇）的通信尤为重要。然而，现有的通信方法具有其自身的局限性，并且水下和空中之间的无线通信仍然是未解决的问题。在本文中，我们提出了一种基于低成本无源继电器的光声通信，该通信不仅能够最大程度地减少水和气水界面的能量损失，而且还可以减轻目标寻找的难度。因此，使用成本低于1.00美元的无源继电器，我们可以将激光能量降低6个数量级（25 J对27μJ）。也证明了我们的光声通信可以在复杂的水情况下（包括波浪和污染）正常工作。