Ni原子双飞秒脉冲激光诱导击穿光谱的信号增强研究

在大气环境下采用波长为800nm，脉宽为30fs的飞秒激光研究了Ni的双脉冲激光诱导击穿光谱，与单飞秒脉冲激光诱导击穿光谱相比，双飞秒脉冲在最优的双脉冲相对延时下，其信号强度增强接近10倍，实验研究了双脉冲相对延时在0-1300ps范围内不同延时对激光诱导击穿光谱信号强度增强因子的影响。整个相对延时区域可以分为三个阶段：在0-50ps区域内信号增强因子是一个持续增大的过程，在50ps左右，达到一个最大值；在50-300ps区域内，信号增强因子呈现出一个先下降后上升的过程；在300-1300ps，信号增强因子基本保持不变。

Investigation on the signal enhancement of the double femtosecond pulse laser-induced breakdown spectroscopy of nickel

Double femtosecond pulse laser-induced breakdown spectroscopy (LIBS) of nickel was investigated by using two 30-fs laser radiation, both at 800 nm, in the collinear configuration under ambient conditions. In comparison with the single-pulse (SP) LIBS, the signal enhancement of a nearly 10 fold was achieved with double-pulse (DP) radiations at the optimum inter-pulses delay. The influence of the inter-pulse delay on the LIBS signal intensity within 0-1300 ps was investigated and three temporal intervals of interaction were observed. From 0 to 50 ps, the intensity of the emission lines increases steadily and a maximum is reached at approximately 50 ps; from 50 to 300 ps, the signal enhancement factor decreases firstly and then increases; from 300 to 1300 ps, the signal enhancement factor remains constant.