聚焦透镜到靶材表面距离对等离子体红外光谱的影响
Effect of the Distance from the Focusing Lens to the Target Surface on the Infrared Spectrum

使用Nd:YAG纳秒脉冲激光诱导铝靶材产生等离子体，通过改变聚焦透镜到靶材表面的距离(LTSD)，观察原子光谱的强度变化。在实验研究的波长范围内，我们讨论的谱线为O I 1128 nm、N I 1249 nm和Al I 1312 nm。结果表明，谱线强度随着LTSD的变化而变化；针对75 mm焦距的聚焦透镜，O和Al的谱线强度在LTSD为70 mm处到达最大值，N的谱线则是靶材表面在焦点处最大。
Nd:YAG nanosecond pulsed laser was used to induce the aluminum target to generate plasma. By changing the distance from the focusing lens to the target surface (LTSD), the intensity of the atomic spectrum and the change of the plasma morphology were observed. In the wavelength range of the experimental study, the spectral lines we discussed are O I 1128 nm, N I 1249 nm, and Al I 1312 nm. The results show that the intensity of the spectral line changes with the change of LTSD. For a focusing lens with a focal length of 75 mm, the spectral intensity of O and Al reaches the maximum at LTSD of 70 mm, and the spectral line of N is the maximum at the focal point of the target surface.