Quasi-phase-matched high-harmonic generation in gas-filled hollow-core photonic crystal fiber

Florian Wiegandt, Patrick N. Anderson, Fei Yu, Daniel J. Treacher, David T. Lloyd, Peter J. Mosley, Simon M. Hooker, Ian A. Walmsley

Research output: Contribution to journalArticlepeer-review

17 Citations (SciVal)


High-order harmonic generation (HHG) provides a promising tabletop source of coherent short wavelength radiation. However, the low generation efficiency limits the mean photon flux of HHG sources when driven with low average power, kHz repetition rate lasers. The HHG flux could be increased by employing MHz repetition rate driving lasers. However, the low pulse energy necessitates tight focusing, which limits the effective interaction volume. Generating harmonics in a gas-filled photonic crystal fiber (PCF) mitigates this problem, but for both free focus and PCF targets, the HHG conversion efficiency is optimized at technologically challenging multibar gas pressures. Here, we perform HHG with μJ-level driving pulses in a hollow-core PCF. We observe dramatic 60-fold enhancement of the HHG flux through a time-multiplexed multimodal quasi-phase-matching technique at low gas pressures. We also observe high harmonic photon energies up to 61.6 eV with continuous spectral tunability made possible by controlled ionization-induced blue shifting of the driving laser.

Original languageEnglish
Article number348189
Pages (from-to)442-447
Number of pages6
Issue number4
Early online date4 Apr 2019
Publication statusPublished - 4 Apr 2019

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics


Dive into the research topics of 'Quasi-phase-matched high-harmonic generation in gas-filled hollow-core photonic crystal fiber'. Together they form a unique fingerprint.

Cite this