Experimental demonstration of measuring angle of incidence for light into receiver in underwater laser communication system based on four-quadrant detector

作者：Yuan Wei Peng, Bili Li, Yongqiang Kang, Yunzhou Zhu, Qihang Sun, Zhepeng Huang, Biao Han · 年份：2024 · DOI：10.1117/12.3018551 · 研究领域：Optical Wireless Communication Technologies、Underwater Vehicles and Communication Systems、Image Enhancement Techniques

Underwater wireless optical communication (UWOC) is an useful way to transmit date in ocean with short distance, because it has high speed. In application, the first challenge for this technology is establishing optical link underwater. There are two schemes to deal with this issue. The first one is enlarging the angle of divergence of the transmitter, and the field of view of receiver, which reduces the requirement to align the UWOC transmitter and receiver. However, the energy loss is increased in the transmission link. The other method needs a pointing, acquisition, and tracking (PAT) system to establish optical link. The angle of divergence of the transmitter is quite small in this way, which is helpful to reduce energy loss in the transmission link. However, in order to make the optical link stable, the receiver should measure the angle of incident of communication light all the time to provide feedback parameters to PAT system. In this work, a method is presented and demonstrated based on four-quadrant detector (QD) for such issue. It shows that the tested error for pitch angle and azimuth angle is less than 1°, as the communication system could still work with 50Kbps communication rate and 2m distance. It has demonstrated the feasibility of the method.