Laser Control of Vibrational Transfer Based on Exceptional Points

Abstract

The coalescence of two Floquet resonances with complex quasi-energies in the photodissociation of a molecule can be reached through an appropriate choice of laser parameters (wavelength and intensity). The corresponding point in the parameter plane is called exceptional. We show that a condition for two resonances to yield such a point is that they correspond, respectively, to a shape-like resonance and a Feshbach-like resonance. We examine how the resonances behave along a contour in the parameter plane, which goes around the exceptional point. The resonances exchange their labels. This amounts to a laser control of the vibrational transfer of the undissociated molecules from one field-free state to another.