Brillouin scattering spectrum for liquid detection and applications in oceanography

The Brillouin scattering spectrum has been used to investigate the properties of a liquid medium. Here, we propose an improved method based on the double-edge technique to obtain the Brillouin spectrum of a liquid. We calculated the transmission ratios and deduced the Brillouin shift and linewidth to construct the Brillouin spectrum by extracting the Brillouin edge signal through filtered double-edge data. We built a detection system to test the performance of this method and measured the Brillouin spectrum for distilled water at different temperatures and compared it with the theoretical prediction. The observed difference between the experimental and theoretical values for Brillouin shift and linewidth is less than 4.3 MHz and 3.2 MHz, respectively. Moreover, based on the double-edge technique, the accuracy of the extracted temperatures and salinity is approximately 0.1 degrees C and 0.5%, respectively, indicating significant potential for application in water detection and oceanography.

Automated summary

The Brillouin scattering spectrum of a liquid medium was investigated using an improved method based on the double-edge technique. The Brillouin spectrum was constructed by calculating transmission ratios and deducing the Brillouin shift and linewidth through filtered double-edge data. The experimental values of Brillouin shift and linewidth for distilled water were compared with theoretical predictions, showing a small difference of less than 4.3 MHz and 3.2 MHz, respectively. The double-edge technique also demonstrated high accuracy in extracting temperatures and salinity, indicating significant potential for application in water detection and oceanography.