CAJ | 학술논문

基于动理论Vlasov-Poisson方程,建立了超短脉冲激光引起的SiO2材料表面库仑爆炸烧蚀机理的理论模型,计算了在多光子吸收与雪崩2种电离机制下材料中自由电子的非平衡态分布,并在此基础上定量分析了自洽电场导致的材料表面库仑爆炸的机理及激光参数对材料表面烧蚀的影响.结果表明,在飞秒激光作用下自由电子弛豫时间不是常数,而是与自由电子微观状态有关,表明弛豫时间近似模型在飞秒时间尺度下是不适用的.理论模型的烧蚀深度数值计算结果在0～1 ps脉宽范围均与实验吻合得较好.
기우동이론Vlasov-Poisson방정,건립료초단맥충격광인기적SiO2재료표면고륜폭작소식궤리적이론모형,계산료재다광자흡수여설붕2충전리궤제하재료중자유전자적비평형태분포,병재차기출상정량분석료자흡전장도치적재료표면고륜폭작적궤리급격광삼수대재료표면소식적영향.결과표명,재비초격광작용하자유전자이예시간불시상수,이시여자유전자미관상태유관,표명이예시간근사모형재비초시간척도하시불괄용적.이론모형적소식심도수치계산결과재0～1 ps맥관범위균여실험문합득교호.
Based on the kinetic theoretical Vlasov-Poisson equation,a surface Coulomb explosion model of SiO2 material induced by ultra-short pulsed laser radiation is established.The non-equilibrium free electron distribution resulting from the two mechanisms of multi-photon ionization and avalanche ionization is computed.A quantitative analysis is given to describe the Coulomb explosion induced by the self-consistent electric field,and the impact of the parameters of laser pulses on the surface ablation is also discussed.The results show that the electron relaxation time is not constant,but it is related to the microscopic state of the electrons,so the relaxation time approximation is not available on the femtosecond time scale.The ablation depths computed by the theoretical model are in good agreement with the experimental results in the range of pulse durations from 0 to 1 ps.