High resolution spectroscopy and perturbation analysis of the CO A¹Π −X¹Σ⁺ (0,0) and (1,0) bands

Abstract

The two lowest-v′ (0,0) and (1,0) bands of the A1Π −X1Σ+ system of 12C16O have been investigated by two high-resolution spectroscopic methods. A vacuum ultraviolet Fourier-transform spectrometer, illuminated by synchrotron radiation, was applied to record a jet-cooled spectrum and a room temperature static gas spectrum, resulting in absolute accuracies of 0.01−0.02 cm−1. In addition two-photon Doppler-free laser spectroscopy has been applied to a limited number of rotational lines, resulting in an accuracy of 0.002 cm−1. The data were used to perform an improved analysis of the perturbations in the A1Π, v = 0 and v = 1 levels by vibrational levels in the D1Δ, I1Σ−, e3Σ−, d3Δ. and a′3Σ+ states.