液体产生太赫兹波的特性研究

Characteristics of terahertz wave generated from liquids

最新的实验研究表明通过激光激发液体诱导等离子体可产生宽带太赫兹波,且液体作为太赫兹波辐射源具有独特的性质。液体具有与固体相当的物质密度,激光在一定区域内与分子的相互作用比气体多三个数量级;而与固体相比,液体的流动性使得每一个激光脉冲可与目标物液体靶的新区域相互作用。这些特性使得液体在高能量密度等离子体的研究中具有广阔的前景,甚至有可能成为下一代太赫兹波辐射源。本文全面综述了液体的流体状态和种类、激光入射位置和角度、脉冲持续时间以及脉冲能量等因素对产生太赫兹波的影响。

Recently,broadband THz wave generation from a liquid target excited by femtosecond laser has been experimentally demonstrated,and it is found that liquid has unique properties as a terahertz wave radiation source.Liquid has the comparable material density to that of solid,which means that laser pulses will interact with three orders more molecules for liquid source than for gas source.In the other hand,compared with solid,the fluidity of the liquid allows each laser pulse to interact with a fresh area of the target,which means that intense laser pulse is not an issue of material damage or degradation.These characteristics make liquid very promising for the study of high-energy density plasma and even becoming the next generation of THz source.In this paper,the influences of the shape and type of liquid target,incidence position and angle of laser beam,pulse duration and energy on THz wave generation are reviewed.