title: Rapid passage signals from a vibrationally excited target molecule: a pump and probe experiment with continuous wave quantum cascade lasers.
abstract: Two 5 µm continuous wave quantum cascade lasers are used to perform a counterpropagating pump and probe experiment on a low pressure sample of nitric oxide. The strong pump field excites a fundamental rovibrational transition and the weaker probe field is tuned to the corresponding rotationally resolved hot band transition. When both light fields are in resonance, rapid passage is observed in the hot band absorption lineshape arising from a minimally damped and velocity-selected sample of molecules in the v=1 state. The measured rapid passage signals are well described by a two-level model based on the optical Bloch equations.
authors.affiliation: Department of Chemistry, The Physical and Theoretical Chemistry Laboratory, The University of Oxford, Oxford, UK.
authors.forename: R J
authors.initials: RJ
authors.lastname: Walker
authors.forename: J H
authors.initials: JH
authors.lastname: van Helden
authors.forename: J
authors.initials: J
authors.lastname: Kirkbride
authors.forename: E A
authors.initials: EA
authors.lastname: McCormack
authors.forename: M T
authors.initials: MT
authors.lastname: Bell
authors.forename: D
authors.initials: D
authors.lastname: Weidmann
authors.forename: G A D
authors.initials: GA
authors.lastname: Ritchie