液体流动对激光光束质量的影响  

Influence of Liquid Flow on Laser Beam Quality in Liquid Lasers

作　　者：王墨戈[1] 许晓军[1] 陆启生[1] 

机构地区：[1]国防科学技术大学光电科学与工程学院定向能技术研究所,湖南长沙410073

出　　处：《中国激光》2010年第1期131-135,共5页Chinese Journal of Lasers

摘　　要：液体的可流动性为液体激光器热管理提供便利,研究液体流动状态对激光光束质量的影响对液体激光器研制具有一定的现实意义。采用Fluent软件,模拟了激光系统增益区液体介质横向流动状态。结果表明,介质流速较为均匀稳定,对于激光光束质量不会产生大的影响。实验测量了液体介质流速分别为0.48,1.51和5.39 L/min时,通过增益区的信标光(He-Ne光)相位分布,信标光的斯垂耳(Strehl)比为0.9964,0.9960及0.9936。在纵向均匀抽运条件下,粘性流动的非均匀性使得信标光的光束质量与理想流动相比略有下降,抽运功率密度为46.9 W/cm2,流速分别为0.48和5.39 L/min时信标光的Strehl比为0.9484和0.9995。当抽运功率密度升高至100 W/cm2,两种流速状态下的信标光的Strehl比为0.1051和0.9978。加快液体的流动速度可以减少因介质流速的不均匀而引起的波前畸变。Liquid flow has positive implication for the thermal management in liquid lasers.The flowing state of liquid can considerably influence the laser beam quality.By the aid of the commercial software Fluent,the transverse flowing states of liquid media in gain area are simulated.Based on the wave-front curving sensing technology and the Green′s functions wave-front reconstruction arithmetic,the phase distribution of the probe laser（He-Ne laser） is measured when the flow rates are 0.48,1.51 and 5.39 L/min.The Strehl ratios are 0.9964,0.9960 and 0.9936,respectively.The results show that when the flow rate is stable,the laser beam quality is almost not affected by the liquid flowing state.Under the longitude uniform pumping circumstances,the laser beam quality in viscous flowing state is slightly reduced compared to that in uniform flowing state.When the pumping power density is 46.9 W/cm^2,the Strehl ratios are 0.9484 and 0.9995,in which the flow rates are 0.48 and 5.39 L/min.The Strehl ratio decrease to 0.1051 and 0.9978,when the pumping power density increases to 100 W/cm^2 and the flow rate keeps the same.The wave-front aberration arising out of the heterogeneity of the flow rate can be decreased by promoting the flow rate of the liquid media.

关 键 词：激光技术 液体激光 横向流动 光束质量 

分 类 号：TN248.3[电子电信—物理电子学]