Experimental Investigation on Underwater Opto-Acoustic Communication

Abstract

The underwater opto-acoustic communication system for directional acoustic communication between an in-air platform and a submerged platform operating is important. The paper presents a new method to solve this problem with opto-acoustic technology, which combines high-energy laser, the opto-acoustic transmitter that optical energy is converted to acoustic energy at the water surface. The laser-based transmitter provides a versatile method for generating underwater sound. The acoustic pressure is linearly proportional to the laser power. The paper designed an experimental measurement system for the opto-acoustic communication. It made experiments for study on the waveform and spectrum characteristics of opto-acoustic signals. The paper also discuss the acoustic wave after optical breakdown in water with Nd:YAG laser pulses. The opto-acoustic signals can controll by adjusting the laser's parameters. The conclusion is that the opto-acoustic communication has some technical advantages. This system presents a change in the way communicational from the air.

A Contrastive Study on LiMn₂O₄ Prepared by Solution Combustion Synthesis Using Nitrate or Acetate Salts as Raw Materials

“…For the conventional solution combustion synthesis, nitrate salts are generally used as raw materials. In our previous research [7,8] it was found, that the utilization of the nitrate salts as raw materials was the main reason that it is hard to get LiMn 2 O 4 with high purity at lower temperatures. In this paper, the acetate salts were used as raw materials and acetic acid as fuels to prepare LiMn 2 O 4 .…”