Unusual Low-Intensity Regime in Laser-Induced Molecular Photodissociation

摘要

Previous investigations of laser-induced photodissociation of a diatomic molecule (Atabek et al., Phys Rev A 2006, 74,063412 and Atabek and Lefebvre, Phys Rev A 2008, 78, 043419) have shown that some of the Floquet eigenstates have the property that at some critical intensities their width is vanishing. These intensities are wavelength dependent. We exploit further this property by showing that by a proper choice of the wavelength, the critical intensity for a Floquet state originating from a given field-free vibrational state can be made vanishingly small. In such a case, the rate increases with intensity in an abnormally slow way. The wavelengths, which are required to reach this regime, can be derived accurately from the semiclassical criterion to obtain a zero-width resonance.