Absorption Lines of O2 and HF in KrF Laser Spectrum

Absorption lines in the KrF laser spectrum corresponding to impurities produced by shots of pulsed discharge are investigated. Wavelengths of strong absorption lines of the O 2 Schumann-Runge, B–X , system (2–7) band are revised taking the effects of triplet structures into account. Rotational lines of (0–6), (7–9) and (4–8) bands of O 2 B–X are newly assigned. Rotational lines of the HF B–X system (0–15), (1–16) and (3–18) bands are confirmed by their decreasing intensity with increasing number of shots. Relative intensities of rotational lines of the (2–7) band give the rotational temperature of 400±50 K. Spectra observed using a multichannel detector in the 7th order of the 6.65-m grating spectrograph (FWHM 3.37 pm) are used to obtain the absorption cross section, σ, of the (2–7) band. The population in v ′′ =7 obtained from the σ value is consistent with the results previously obtained for the ArF laser.