• Photonics Research
  • Vol. 10, Issue 3, 637 (2022)
Krishna Murari1、2、3、*, Giovanni Cirmi1、4, Hüseyin Cankaya1、4, Gregory J. Stein1, Benoit Debord5, Frederic Gérôme5, Felix Ritzkosky1, Fetah Benabid5, Oliver Muecke1、3, and Franz X. Kärtner1、2、4
Author Affiliations
  • 1Center for Free Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
  • 2Max-Planck Institute for Structure and Dynamics of Matter (MPSD), 22761 Hamburg, Germany
  • 3ELI-ALPS, ELI-HU Non-Profit Ltd., Szeged H-6728, Hungary
  • 4The Hamburg Center for Ultrafast Imaging & Department of Physics, University of Hamburg, 22761 Hamburg, Germany
  • 5GPPMM Group, XLIM Research Institute, UMR 7252 CNRS, University of Limoges, Limoges, France
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    DOI: 10.1364/PRJ.441674 Cite this Article Set citation alerts
    Krishna Murari, Giovanni Cirmi, Hüseyin Cankaya, Gregory J. Stein, Benoit Debord, Frederic Gérôme, Felix Ritzkosky, Fetah Benabid, Oliver Muecke, Franz X. Kärtner. Sub-50 fs pulses at 2050 nm from a picosecond Ho:YLF laser using a two-stage Kagome-fiber-based compressor[J]. Photonics Research, 2022, 10(3): 637 Copy Citation Text show less

    Abstract

    The high-energy few-cycle mid-infrared laser pulse beyond 2 μm is of immense importance for attosecond science and strong-field physics. However, the limited gain bandwidth of laser crystals such as Ho:YLF and Ho:YAG allows the generation of picosecond (ps) long pulses and, hence, makes it challenging to generate few-cycle pulse at 2 μm without utilizing an optical parametric chirped-pulse amplifier (OPCPA). Moreover, the exclusive use of the near-infrared wavelength has limited the generation of wavelengths beyond 4 μm (OPCPA). Furthermore, high harmonic generation (HHG) conversion efficiency reduces dramatically when driven by a long-wavelength laser. Novel schemes such as multi-color HHG have been proposed to enhance the harmonic flux. Therefore, it is highly desirable to generate few-cycle to femtosecond pulses from a 2 μm laser for driving these experiments. Here, we utilize two-stage nonlinear spectral broadening and pulse compression based on the Kagome-type hollow-core photonic crystal fiber (HC-PCF) to compress few-ps pulses to sub-50 fs from a Ho:YLF amplifier at 2 μm at 1 kHz repetition rate. We demonstrate both experimentally and numerically the compression of 3.3 ps at 140 μJ pulses to 48 fs at 11 μJ with focal intensity reaching 1013 W/cm2. Thereby, this system can be used for driving HHG in solids at 2 μm. In the first stage, the pulses are spectrally broadened in Kagome fiber and compressed in a silicon-based prism compressor to 285 fs at a pulse energy of 90 μJ. In the second stage, the 285 fs pulse is self-compressed in air-filled HC-PCF. With fine-tuning of the group delay dispersion (GDD) externally in a 3 mm window, a compressed pulse of 48 fs is achieved. This leads to a 70-fold compression of the ps pulses at 2050 nm. We further used the sub-50 fs laser pulses to generate white light by focusing the pulse into a thin medium of YAG.
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    Krishna Murari, Giovanni Cirmi, Hüseyin Cankaya, Gregory J. Stein, Benoit Debord, Frederic Gérôme, Felix Ritzkosky, Fetah Benabid, Oliver Muecke, Franz X. Kärtner. Sub-50 fs pulses at 2050 nm from a picosecond Ho:YLF laser using a two-stage Kagome-fiber-based compressor[J]. Photonics Research, 2022, 10(3): 637
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