[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.