Characterization of high-harmonic emission from ZnO up to 11 eV pumped with a Cr:ZnS high-repetition-rate source

Opt Lett. 2019 Jan 15;44(2):259-262. doi: 10.1364/OL.44.000259.

Abstract

We report the measurement of high-order harmonics from a ZnO crystal with photon energies up to 11 eV generated by a high-repetition-rate femtosecond Cr:ZnS laser operating in the mid-infrared at 2-3 μm, delivering few-cycle pulses with multi-watt average power and multi-megawatt peak power. High-focus intensity is achieved in a single pass through the crystal without a buildup cavity or nanostructued pattern for field enhancement. We measure in excess of 108 high-harmonic photons/second.