长脉冲激光诱导单晶硅产生等离子体特性

Plasma characteristics of monocrystalline silicon induced by long pulse laser

针对毫秒脉冲激光诱导单晶硅产生等离子体演化规律,利用光学阴影成像法研究单晶硅燃烧波膨胀过程,分析不同时刻等离子体状态,采用双端口光谱仪分析等离子体光谱,计算等离子体的主要特征参数.结果表明:随着激光能量密度的增加,燃烧波膨胀距离和膨胀速度增大,径向膨胀速度小于轴向膨胀速度;等离子体主要在单晶硅表面附近加速最大;等离子体膨胀时,观察到长脉冲特有的喷溅现象;激光能量密度在337.0~659.7 J/cm2之间时,电子温度量级为104 K,等离子体电子温度、电子密度随激光能量密度增加而增加.

Aiming at the plasma evolution law of monocrystalline silicon induced by the millisecond pulse laser,the expansion process of combustion wave of monocrystalline silicon was studied with the optical shadow imaging method,and the plasma status at different moments was analyzed.A dual-port spectrometer was used to analyze the plasma spectra,and the main characteristic parameters of the plasma were calculated.The results show that the expansion distance and expansion velocity of combustion wave increase with the laser energy density,and the radial expansion velocity is smaller than that in axial direction.The plasma accelerates mainly near the surface of monocrystalline silicon.When the plasma expands,a unique splash phenomenon of long pulse was observed.When the laser energy density is between 337.0 J/cm2 and 659.7 J/cm2,the electronic temperature is on the order of 104 K.The electron temperature and electron density of plasma increase with the increase of laser energy density.