分别对低于0.1 MPa的空气和氩气环境气体条件下的飞秒激光镍等离子体光谱进行了实验研究。结果表明，在两种环境气体中，激光镍等离子体光谱均表现为连续谱和原子线状谱的叠加。随着环境气压的降低，由于电子密度的下降，从而使得低压条件下的谱线比高压条件下的谱线具有更好的分辨特性。同时，谱线强度经历了由缓慢增强发展到迅速降低的演化过程。另外，还讨论了环境气体成分对谱线强度的影响。

The spectra of Ni plasma induced by femtosecond laser pulses at sub-atmospheric pressure environment have been studied experimentally in air and argon gas, respectively. The results show that the spectra of laser-induced plasmas are composed of continuous spectra and atomic line spectra in these two surrounding gases. The spectra at lower surrounding pressure show higher resolution due to the decrease of electron density, compared to that at higher pressure. Besides, the intensity of line spectra undergoes the transition from slow increase to rapid decrease. Additionally, the effect of the composition of the surrounding gas on the intensity is also briefly discussed.