Erlangen 2018 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
K: Fachverband Kurzzeit- und angewandte Laserphysik
K 1: Optical Methods - EUV and x-ray Sources
K 1.4: Vortrag
Montag, 5. März 2018, 15:10–15:25, MB HS
Continuously wavelength-tunable high harmonics generation via soliton dynamics — •Francesco Tani1, Michael H. Frosz1, John J.C. Travers1,2, and Philip St.J. Russell1 — 1Max Planck Institute for the Science of Light, Staudtstr. 2, 91058 Erlangen, Germany — 2School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK
Soliton dynamics offer a range of powerful tools for nonlinear manipulation of ultrashort light pulses. In gas-filled hollow-core photonic crystal fiber (HC-PCF), the weak anomalous dispersion supports solitons over a broad spectral range in the visible and infrared regions. By exploiting these dynamics, gas-filled HC-PCFs have been successfully used, within a broad range of laser wavelengths, for pulse self-compression down to single cycle durations and for upshifting the pulse central frequency. Here we combine a gas-filled HC-PCF with a gas-jet for high harmonic generation (HHG), driven by laser pulses of a few tens of micro-Joule, which undergo soliton self-compression in the fiber. We show that by exploiting the interaction of the soliton with free electrons created by ionization in the gas, we can continuously upshift the soliton frequency and as a result tune the frequency of the generated harmonics. In this way, we achieved a blue-shift of almost 3 eV, while keeping the ionization in the gas jet at a low level (high levels degrade the coherence of the harmonics). The high efficiency and low pulse energies suggest that this HHG scheme will open a new route to developing a tunable extreme ultraviolet sources that, uniquely, can easily be scaled to MHz repetition rates.