title: Third and fifth harmonic generation by tightly focused femtosecond pulses at 2.2 μm wavelength in air.
abstract: We report experiments on the generation of third and fifth harmonics of millijoule-level, tightly focused, femtosecond laser pulses at 2.2 μm wavelength in air. The measured ratio of yields of the third and fifth harmonics in our setup is found equal to 2 · 10(-4). This result contradicts the recent suggestion that the Kerr effect in air saturates and changes sign in ultra-intense optical fields.
authors.affiliation: College of Optical Sciences, The University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Gombojav O
authors.initials: GO
authors.lastname: Ariunbold
authors.forename: Pavel
authors.initials: P
authors.lastname: Polynkin
authors.forename: Jerome V
authors.initials: JV
authors.lastname: Moloney
mesh_terms: D000388:Air; D004867:Equipment Design; D007834:Lasers; D007909:Lenses; D055095:Optics and Photonics / Q000295:instrumentation* / Q000379:methods*; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods*