Comparative investigation of third and fifth harmonic generation in atomic and molecular gases driven by mid-infrared ultrafast laser pulses

Abstract

We report on the comparative experimental investigation on third and fifth harmonic generation (THG and FHG) in atomic and molecular gases driven by mid-infrared ultrafast laser pulses at a wavelength of ~1500 nm. We observe that the conversion efficiencies of both the THG and FHG processes saturate at similar peak intensities close to ~1.5\times1014 W/cm2 for argon, nitrogen, and air, whose ionization potentials are close to each other. Near the saturation intensity, the ratio of yields of the FHG and THG reaches ~10-1 for all the gases. Our results show that high-order Kerr effects do exist, whereas they are insufficient to balance the Kerr self-focusing without the assistance of plasma generation.

16 pages, 3 figures

References in corpus (5)

• Higher-order Kerr terms allow ionization-free filamentation in gases
• Transition from plasma- to Kerr-driven laser filamentation
• Optical nonlinearity in Ar and N${}_2$ near the ionization threshold
• Experimental Tests of the New Paradigm for Laser Filamentation in Gases
• From higher-order Kerr nonlinearities to quantitative modeling of 3rd and 5th harmonic generation in argon

Cited by in corpus (3)

• Harmonic-seeded remote laser emissions in N2-Ar, N2-Xe and N2-Ne mixtures: a comparative study
• Combined action of the bound-electron nonlinearity and the tunnel-ionization current in low-order harmonic generation in noble gases
• Signature of multi-channel interference in high-order harmonic generation from N2 driven by intense mid-infrared pulses