Optical breakdown laser-generated sound in water

One possibility for communicating from an airplane above water surface to submarine in sea involves the use of laser-generated sound. In this paper, we introduce the way to generate strong optical breakdown acoustic signal in a limited large volume of water but enough to do basic work in air-submarine communication realm. The optical breakdown mechanism of strong Nd:YAG laser pulse with water generates acoustic signals in water having pulse widths about 25 mu s and a frequency spectrum peak about 58kHz. And, its sound source level (SSL) of 196 dB for low frequencies less than 58kHz is sufficient to be detected at far distant deep in water. This makes a stride for pursuing the feasibility of laser-acoust air-submarine communication.