Generation of resonance-enhanced fifth harmonic in xenon with Bessel-Gauss laser beams

摘要

Generation of a tunable resonance-enhanced fifth harmonic in xenon under excitation by tightly focused Gaussian and Bessel-Gauss laser beams has been studied through multiphoton ionization measurements. It has been shown that the transformation of a Gaussian beam into a Bessel-Gauss one results in a red shift of the fifth-harmonic excitation profile toward the atomic resonance. The tuning curves and the relative efficiency of harmonic generation in Gaussian and Bessel-Gauss laser beams have been compared and discussed.