title: High-order harmonic generation from solid targets with 2 mJ pulses.
abstract: Harmonics up to the 18th order are generated from solid targets by focusing 2 mJ, 50 fs pulses at 800 nm to a spot size of 1.7 μm (FWHM). To our knowledge, this is the first demonstration of high-harmonic generation with a very short focal length paraboloid (f/1.4) and kilohertz laser system. The harmonics have a low divergence (<4°) compared to the driving beam and conversion efficiencies (>10(-7) per harmonic) comparable to gas harmonics. No contrast enhancement techniques are employed, and the system is capable of operating at 500 Hz.
authors.affiliation: Center for Ultrafast Optical Science, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, Michigan 48109, USA. jheaster@umich.edu
authors.forename: James H
authors.initials: JH
authors.lastname: Easter
authors.forename: Aghapi G
authors.initials: AG
authors.lastname: Mordovanakis
authors.forename: Bixue
authors.initials: B
authors.lastname: Hou
authors.forename: Alexander G R
authors.initials: AG
authors.lastname: Thomas
authors.forename: John A
authors.initials: JA
authors.lastname: Nees
authors.forename: Gérard
authors.initials: G
authors.lastname: Mourou
authors.forename: Karl
authors.initials: K
authors.lastname: Krushelnick