布里渊激光雷达系统中的关键因素研究

摘要

基于德拜热运动的弹性波理论,考虑激光雷达的光散射效应,提出了布里渊激光雷达系统中的布里渊线宽的选择方法,并推导出散射光谱中的斯托克斯线和反斯托克斯线两条伴线的相对频移公式；分析指出,在介质中,由于弹性波总是有衰减,所以,布里渊谱线的线宽不为零；建立了布里渊激光雷达系统实验模型,通过选取适当的参数进行模拟计算,进一步讨论了布里渊线宽与海水温度的关系；得到了不同海水温度下的布里渊线宽曲线,从而清晰的表明,在激光雷达系统中,布里渊线宽并不是一个常值,在其他参量不变的情况下,随着海水温度的升高,布里渊线宽会逐渐变窄.%Based on elastic wave theory of Debye thermal motion,considering light scattering effect of lidar,a method is proposed to select Brillouin line width in Brillouin lidar system. And the relative frequency shift formulas of Stokes line and anti-Stokes line are deduced at scattered spectrum. Analytically,elastic wave is always attenuated in medium, so the Brillouin line width would not be zero. The Brillouin lidar system test model is built. The simulation is carried out through appropriate selection of parameters. The relationship curve between Brillouin line width and different sea-water is obtained. From the curve, it is clearly demonstrated that the Brillouin line width is not a constant in lidar system. Under the condition of other parameters unchanged, Brillouin line width will gradually become narrow with the rise of the seawater temperature.