Observation of an infrared band sequence in molecular oxygen at 01 Torr

Abstract

The 1–5-μm emission spectrum from the negative glow of a pulsed oxygen discharge at 0.1 Torr has been examined with a Fourier spectrometer in the time-resolved mode. In addition to well-known atomic lines, our spectrum contains nine regularly spaced linelike features around 4000 cm⁻¹. We interpreted these features as molecular Rydberg–Rydberg transitions of the type ΔΛ = 1 and Δv = 0. Additional features at 7000 cm⁻¹ are assigned to the f ¹∑_u⁺−d ¹Π_g transition in oxygen, resulting in greatly improved spectroscopic constants for the d state.