High-harmonics of harmonics of a fiber laser: a milliwatt XUV ultrashort source

TL;DR

This paper explores high-harmonic generation using different harmonics of a fiber laser, demonstrating that the third harmonic yields the most efficient extreme ultraviolet radiation suitable for ultrashort pulse applications.

Contribution

It introduces a method to enhance single-atom response in high-harmonic generation by using harmonics of a fiber laser, with optimal efficiency observed at the third harmonic.

Findings

Third harmonic yields highest efficiency at 4.4×10^14 photons/sec

Achieved 1.3 mW average power at 18 eV

Demonstrated potential for ultrashort EUV pulse sources

Abstract

Recent progresses in femtosecond ytterbium-doped fiber laser technology areopening new perspectives in strong field physics and attosecond science. Highorder harmonic generation from these systems is particularly interesting because it provides high flux beams of ultrashort extreme ultraviolet radiation. A lot of efforts have been devoted to optimize the macroscopic generation parameters. Here we investigate the possibility of enhancing the single-atom response by producing high-harmonics from the second, third and fourth harmonics of a turnkey Yb-fiber laser at 1030 nm. We show that the harmonic efficiency is optimal when the process is driven by the third harmonic, producing 4.4 1014 photon/s at 18 eV, which corresponds to 1.3 mW average power.