Abstract

In this paper, a new method of measuring a water-stimulated Brillouin scattering (SBS) frequency shift by optical coherent detection is presented, in order to remote-sense the underwater temperature of the ocean. A single longitudinal mode, passively $Q$-switched pulsed Nd:YAG laser is used as the light source, the water SBS beam is used as the signal beam, and a portion of the incident laser beam is used as the local oscillator. The heterodyne is detected by a high-speed photodetector, and the heterodyne frequency is the Brillouin frequency shift. Therefore, the underwater temperature can be determined according to the relationship between the Brillouin frequency shift and the water temperature. To test and verify its practicability, the heterodyne waveforms at different water temperatures are recorded in the laboratory with a wide-band oscilloscope, and the Brillouin frequency shifts are deduced by a Fourier transform. The experimental results are consistent with the theoretical analysis. This work provides the foundation for the development of a water temperature measurement system based on coherent Brillouin scattering.

© 2015 Optical Society of America

Influence of temperature-salinity-depth structure of the upper-ocean on the frequency shift of Brillouin LiDAR

Ning Xu, Zhiqiang Liu, Xianda Zhang, Yupeng Xu, Ningning Luo, Shujing Li, Jinjun Xu, Xingdao He, and Jiulin Shi
Opt. Express 29(22) 36442-36452 (2021)

Distributed fiber temperature and strain sensor using coherent radio-frequency detection of spontaneous Brillouin scattering

Jihong Geng, Sean Staines, Mike Blake, and Shibin Jiang
Appl. Opt. 46(23) 5928-5932 (2007)

Retrieval of sound-velocity profile in ocean by employing Brillouin scattering LiDAR

Jiulin Shi, Ning Xu, Ningning Luo, Shujing Li, Jinjun Xu, and Xingdao He
Opt. Express 30(10) 16419-16431 (2022)

Ocean mixed layer depth estimation using airborne Brillouin scattering lidar: simulation and model

Dapeng Yuan, Peng Chen, Zhihua Mao, Xianliang Zhang, Zhenhua Zhang, Congshuang Xie, Chunyi Zhong, and Zheng Qian
Appl. Opt. 60(36) 11180-11188 (2021)

Effects of temperature and pressure on the threshold value of SBS LIDAR in seawater

Jiulin Shi, Dapeng Yuan, Jin Xu, Yangning Guo, Ningning Luo, Shujing Li, and Xingdao He
Opt. Express 28(26) 39038-39047 (2020)