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Title: Comparative investigation of third- and fifth-harmonic generation in atomic and molecular gases driven by midinfrared ultrafast laser pulses

Journal Article · · Physical Review. A
; ; ; ; ; ;  [1];  [2]; ;  [1]
  1. State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China)
  2. Department of Physics, Engineering Physics and Optics, and Center for Optics, Photonics and Laser (COPL), Laval University, Laval, Quebec, G1K 7P4 (Canada)

We report on the comparative experimental investigation on third- and fifth-harmonic generation (THG and FHG) in atomic and molecular gases driven by midinfrared ultrafast laser pulses at a wavelength of {approx}1500 nm. We observe that the conversion efficiencies of both the THG and FHG processes saturate at similar peak intensities close to {approx}1.5 x 10{sup 14} W/cm{sup 2} 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 {approx}10{sup -1} for all the gases. Our results show that high-order Kerr effect seems to exist; however, contribution from the fourth-order Kerr refractive index coefficient alone is insufficient to balance the Kerr self-focusing without the assistance of plasma generation.

OSTI ID:
22095734
Journal Information:
Physical Review. A, Vol. 84, Issue 6; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
Country of Publication:
United States
Language:
English