Laser Excitation Spectra and Lifetime Measurements of the CO d(³Δi) State

Abstract

CO in a supersonic pulsed beam is excited to the d³Δi state by VUV photons generated in a nonlinear four-wave mixing scheme. An excitation spectrum of the CO d³Δi (ν′ = 20, J′ = 1–3) is obtained at a resolution of 0.8 cm⁻¹ for the first time. The radiative lifetimes of the rotational states are measured as 1.70 ± 0.08 μs, which are similar to but shorter than the lifetimes associated with lower vibrational levels.