激光氧气等离子体光谱的时间演化研究

报道了脉冲激光在一个大气压的纯氧(纯度为99.999 9％)中所产生的等离子体光谱进行时间演化特性研究的结果。激光器的工作波长为1.06 μm，光谱探测范围为300～900 nm。实验结果表明，激光氧气等离子体光谱均表现为连续谱和线状谱的迭加，它们的演化过程各不相同。基于各种光谱成分的时间演化特征，分析了激光氧气等离子体在衰变期间可能存在的一些物理过程及其演化特征，讨论了激光氧气等离子体寿命较长的主要原因。这些结果有助于加深对激光大气等离子体特性和机理的了解，为进一步开展延长激光大气等离子体寿命方法的研究提供实验依据。

The Time-Evolution Study on the Laser-Induced Oxygen Plasmas Spectra

The present paper reports the results of spectroscopic study on the oxygen plasma induced by a pulsed laser with a wavelength of 1.06 microm. The gas samples were pure oxygen (99.9999%) and the spectral range was from 300 to 900 nm. The temporal behavior of the spectra was measured. The experiment results showed that the spectra could be divided into continuous spectra and line spectra. Each component of the spectra attenuated according to the disparate mode along temporal development. The microcosmic physical processes and mechanisms were analyzed. The reason for the longer plasma spectral lifetime was discussed. These works were helpful to better understanding of the microscopic mechanisms during the decay of the laser-induced air plasmas, and also provide more experimental evidences for prolonging the decay time of plasmas in some technical applications.