Remote, aerial, opto-acoustic communications and sonar

A remote, aerial, laser-based sonar and communications concept has been demonstrated to direct laser beams from the air onto the water surface to remotely generate and detect underwater sound. This forms the basis for a portable, aerial sonar and communications system for both detecting underwater objects such as vehicles and mines as well as for bidirectional acoustic communication between an in-air platform and a submerged platform operating at speed and depth. Two laser systems are required. The first laser system is a high-energy laser, the opto-acoustic transmitter, whose optical energy is converted to acoustic energy at the water surface. The second laser system is a laser interferometer, the acousto-optic sensor that detects underwater sound by measuring the vibrations of the water surface caused by the incident underwater sound field. Historically, acoustic transmitters and detectors need to be submerged to interact with the underwater environment. This remote, aerial, laser-based sonar and communication system presents a revolutionary change in the way sonar and communications can be realized, by remotely activating and detecting underwater acoustics from the air.