Beyond the Optical Hammer: ultra-fast lasers and ultra-faster molecules

Ryan Coffee,
University of Connecticut

For many years ultra-fast laser pulses have been thought of as "optical hammers." However, we must not forget that we are working with pulses that have reasonably well defined wavelengths, i.e. durations that are not so impulsive. In this seminar, we will compare dissociation mechanisms for the lighter nitrogen molecule with that of iodine, for which 25fs pulses are impulsive. We will see that nitrogen and hydrogen alike dissociate along light-induced potentials whereas iodine has no time to "feel" the light field. This paradigm places different wavelengths on equal footing where we can better identify enhanced ionization and/or multiphoton resonance. Finally we will discuss selective excitations in diatomic molecules, "cheap" adiabatic passage in the multiphoton regime, and a possible broad-band vuv amplification scenario.