Two-color multiphoton ionization and harmonic generation

We present a short summary of results dealing with the harmonic generation in N2 and Ar produced by wave-mixing of parallel polarized fundamental and second harmonics of a Nd-YAG picosecond laser with special regard to the influence of phase-matching due to refractive index electrons produced by two-color multiphoton ionization. Particularly, in this work we compare the harmonic conversion efficacy and the rate of ionization by a self-correlation technique between fundamental and second harmonics of laser. We show that ion and harmonic signal exhibit the same behavior versus the relative delay of both fields. It seems to suggest, at least in our conditions, a positive influence of ionization on harmonic conversion efficiency.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.