Table of Contents
International Journal of Spectroscopy
Volume 2010, Article ID 627571, 6 pages
Research Article

Absorption Line Profile of the 𝟓 𝑆 𝑜 𝟐 𝟓 𝑃 𝟏 Transition of Atomic Oxygen and Its Application to Plasma Monitoring

1Plasma Nanotechnology Research Center, Nagoya University, Nagoya 464-8603, Japan
2Department of Electrical Engineering and Computer Science, Nagoya University, Nagoya 464-8603, Japan

Received 15 April 2009; Accepted 27 May 2009

Academic Editor: Roland Stamm

Copyright © 2010 K. Sasaki et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The line profile of the 5 𝑆 𝑜 2 5 𝑃 1 transition of atomic oxygen was measured by diode laser absorption spectroscopy. As a result, it was found that the absorption line profile had a wing component in the wavelength range detuned from the line center and was not fitted with a Gaussian function. The wing component was considered to be originated from dissociative excitation of molecular oxygen. We fitted the absorption line profile with the superposition of two Gaussian functions corresponding to high and low translational temperatures. We propose that the ratio of the high-temperature to low-temperature components is useful for monitoring the relative degree of dissociation of molecular oxygen in oxygen-containing plasmas. The ratio of the high-temperature to low-temperature components was compared with the survival ratio of molecular oxygen, which was evaluated from the lifetime of O ( 5 𝑆 𝑜 2 ) in the afterglow of pulsed discharges.