提出了一种利用双池受激布里渊散射(SBS)系统选用混合介质,进而测量SBS介质布里渊线宽的方法.在紧凑双池SBS系统的放大池中放入待测介质,在振荡池中放入布里渊频移可调的混合介质,测出放大池待测介质增益系数随布里渊频移偏离的洛伦兹曲线,该曲线半高处的线宽即为待测介质的布里渊线宽.实验上在Nd:YAG调Q激光系统中,选用CCl4/C6H6混合介质,测量了四氯乙烯(C2Cl4)、六氯丁二烯(C4Cl6)、丙酮(C3H6O)和正己烷(C6H14)等介质的布里渊线宽,其值与理论计算值或其他文献值很接近.
In order to measure the Brillouin linewidth of SBS medium, a method using mixture media in two-cell stimulated Brillouin scattering (SBS) system is proposed, which uses the medium to be measured as amplifier medium and the mixture media as generator medium. The profile of gain coefficient versus the difference of Brillouin frequency shift is fitted with Lorentzian curve. The width at half-maximum of this curve is the Brillouin linewidth. In the experiment, using Nd: YAG Q-switched laser system and CCl4/C6 H6 mixture, we measured the Brillouin linewidth of SBS media tetrachloroethylene (C2Cl4), hexachlorobutadiene (C4 Cl6 ), acetone (C3 H6 O) and n-hexane (C6 H14 ) . The results show that the measured values are close to those calculated or published by other authors.