The measured emission spectra of the OH radical subsequent to laser-induced optical breakdown in air are analyzed to infer spectroscopic temperature and species number density. Emissions from the UV <i>A</i><sup>2</sup>∑<sup>+</sup> → <i>X</i><sup>2</sup>II<sub><i>i</i></sub> transition dominate the spectra in the wavelength range of 306–322 nm and for time delays from the optical breakdown of 30–300 μs. Contributions from other species to the recorded OH emission spectra were also investigated for spectroscopic temperature measurements in the range of 2000–6000 K and for OH number densities in the range of 10<sup>14</sup>–2 × 10<sup>16</sup> cm<sup>−3</sup>. Monte Carlo simulations are applied to estimate errors in the analysis of the hydroxyl spectra.
© 2003 Optical Society of America
Christian G. Parigger, Guoming Guan, and James O. Hornkohl, "Measurement and Analysis of OH Emission Spectra Following Laser-Induced Optical Breakdown in Air," Appl. Opt. 42, 5986-5991 (2003)