原子团簇对飞秒激光的吸收

使用800nm飞秒脉冲激光研究了Xe,Ar,He等原子团簇对激光的吸收.实验结果表明,脉冲阀门的工作压力、所使用的气体种类等因素对团簇的尺寸及团簇对激光的吸收影响很大.在阀门工作压力为20×10⁵Pa、激光功率密度为1×10¹⁵W/cm²的条件下,Xe团簇对激光的吸收高达45%.激光预脉冲的存在会降低原子团簇对激光能量的吸收.离子能量测量结果表明,团簇对激光的高效吸收导致较高离子温度等离子体的生 关键词： 原子团簇 飞秒激光 能量吸收效率 高能离子

ABSORPTION OF FEMTOSECOND LASER PULSES BY ATOMIC CLUSTERS

Energy absorption by Xe,Ar,He atomic clusters are investigated using laser pulses with 5mJ energy in 150fs duration.Experimental results show that the size of cluster and laser absorption efficiency are strongly dependent on several factors,such as the working pressure of pulse valve,atomic number Z of the gas.Absorption fraction of Xe clusters is as high as 45% at a laser intensity of 1×10¹⁵W/cm² with 20×10⁵Pa gas jet backing pressure.Absorption of the atomic clusters is greatly reduced by introducing pre-pulses.Ion energy measurements confirm that the efficient energy deposition results in a plasma with very high ion temperature.