Detection Research Of Thermocline Based On Stimulated Brillouin Scattering

Thermocline is an important oceanographic phenomena, the distribution of marineresources and the spread of the signals (such as sonar and light signal) will beinfluenced by the changes in temperature, salinity, density longitudinal distribution ofseawater caused by thermocline, therefor, the research of thermocline has profoundsignificance for the detection and development of marine resources, maritime defenseresearch and climate research. This paper do some research focuses on the influence ofmedium temperature on the characteristics of Stimulated Brillouin Scattering (SBS),including threshold, gain coefficient, linewidth etc.. Then we measure the thermoclinein the water experimental based on the temperature-dependent properties of stimulatedBrillouin scattering.Firstly, this paper does some reseach on the characteristics of Stimulated BrillouinScattering (SBS) gain coefficient under the conditions of variable medium temperature.In this experiment we choose water as the experimental medium, the influence ofwatertemperature on threshold and gain coefficient of stimulated Brillouin scattering (SBS)is investigated theoretically and experimentally by measure attenuation coefficient ofthe broadband and narrowband laser in sink under different water temperatures. Basedon the theoretical analysis, a new method is proposed to determine the gain coefficientof SBS of the material experimentally by measuring the threshold. The experimentalresults indicate that gain coefficient of SBS increases exponentially with the increaseof medium temperature.Secondly, we measure the thermocline in the water experimental based on thetemperature-dependence of Stimulated Brillouin Scattering (SBS). In the laboratory weuse a sink to build a thermocline phenomenon, then we measure the temperaturedistribution of the simulated thermocline based on Stimulated Brillouin Scattering(SBS). We study the basic characteristics of the thermocline by analyzing thetemperature distribution, and we obtained the sub-rule of thermocline. Based on theexperimental measurements,we simulaten and analysis heat conduction equation in thespecial conditions, summed up the characteristics of the time distribution of thethermocline.