Absorption Lines of Vibrationally Excited O2 and HF in ArF Laser Spectrum

Abstract

In a N2 atmosphere the ArF laser spectrum is observed in various spectral resolutions. Many absorption lines sensitive to the O2 impurity produced by shots of the pulsed discharge are observed. All absorption lines are assigned to the rotational lines of HF B–X (3–11) and (4–10), and O2B–X (14–3), (15–3), (16–3), (17–3) and (10–2) bands; some O2 lines in the high-resolution spectrum are resolved into triplet components, and their wavelengths in N2 and relative intensities are given. Quantitative studies on R2,3(5) and R1(5) (14–3) lines are found to satisfy the severe conditions for estimating σ, the absorption cross section. The obtained σ value, and the population ratio in the v=3 to v=2 levels of the ground state, suggest fairly high populations in these excited levels. The HF absorption lines are the strongest, though they decay along with the shot number.