宽带KrF激光抽运SF6受激布里渊散射的脉宽稳定性

Pulse Duration Stability of Stimulated Brillouin Scattering in SF_6 Pumped by a Broadband KrF Laser

从理论和实验上对利用宽带KrF激光抽运SF6产生的受激布里渊散射(SBS)的脉宽稳定性进行了研究。获得了受激布里渊散射脉宽稳定性随抽运功率密度稳定性、抽运脉宽稳定性及介质气压变化的规律。发现受激布里渊散射脉宽的稳定性与抽运激光的稳定性直接相关,抽运激光的稳定性越好,获得的受激布里渊散射脉宽相对稳定性也越好。抽运光脉宽和能量的不稳定都会造成所产生的受激布里渊散射脉宽不稳定。在较低抽运功率密度情况下抽运光脉宽和能量的波动对受激布里渊散射脉宽稳定性的影响都不可忽略,但在较高抽运功率密度情况下受激布里渊散射脉宽稳定性主要受抽运光脉宽波动的影响。对结果进行了分析和讨论,获得脉宽稳定性较好的受激布里渊散射输出的条件是,使用脉宽稳定性较好的抽运光和在保证没有其他非线性效应产生的情况下,尽可能提高抽运光的功率密度和介质气压。

The pulse duration stability of stimulated Brilloiun scattering （SBS） in SF6 gas pumped by a broadband KrF laser was studied theoretically and experimentally. The dependence of the pulse duration stability of SBS on the power density stability, pulse duration stability of the pump laser and medium gas pressure was obtained. The results showed that the pulse duration stability of SBS is directly correlated with the stability of the pump laser; the pulse duration stability of the SBS increases as the stability of the pump laser does. The instability of SBS pulse duration occurrs when pulse duration and energy of pump laser were instability. Under lower pump power density, the influence of the pulse duration and pump laser energy fluctuation on the pulse duration of SBS is not ignored; but under higher pump power density, the pulse duration stability of SBS is mainly influenced by the fluctuating in pump pulse-width. The experimental results were analyzed and discussed. And for obtaining better pulse duration stability of SBS, pump laser with stable pulse duration should be used. And enhancing pump density of pump laser and medium gas pressure without other nonlinear effects are also necessary.