Pulse compression of phase-matched high harmonic pulses from a time-delay compensated monochromator

Abstract

Single 32.6 eV high harmonic pulses from a time-delay compensated monochromator were compressed down to 11 ± 3 fs by completely compensating for the pulse-front tilt. The photon flux was intensified up to 5.7×10 9 photons/s on target by implementing high harmonic generation under a phase matching condition in a hollow fiber used for increasing the interaction length. The output photon flux on target from the monochromator was comparable to that from a small synchrotron facility, while the pulse duration was more than three orders of magnitude shorter. This high harmonic beam line fulfills two requirements for timeresolved spectroscopy in extreme ultraviolet region, namely, ultrashort pulses and high photon flux. R. Leone, "Ultrafast time-resolved soft x-ray photoelectron spectroscopy of dissociating Br2.," Phys. Rev. Lett. ©2012 Optical Society of America

Pulse Compression of Phase-matched High Harmonic Pulses from a Time-Delay Compensated Monochromator

“…Then, in this work, we compressed the 21st harmonic pulses (= 32.6 eV) down to 11 ± 3 fs by adjusting the slit position located between the gratings. To improve the conversion efficiency, high harmonics were generated in a hollow fiber filled with rare gas to increase the interaction length under a phase-matched condition, which was found by changing gas pressure inside the fiber [5].…”

Double-grating monochromatic beamline with ultrafast response for FLASH2 at DESY

“…Double-grating instruments have already been demonstrated to give time resolution below 10 fs in the XUV (Poletto et al, 2009;Ito et al, 2010;Igarashi et al, 2012).…”

“…In the second case, two consecutive gratings are employed: the first one performs the spectral selection on an intermediate slit while the second one corrects for the pulse-front tilt introduced by the diffraction. Double-grating instruments have already been demonstrated to give time resolution below 10 fs in the XUV (Poletto et al, 2009;Ito et al, 2010;Igarashi et al, 2012).…”

Femtosecond photoelectron and photoion spectrometer with vacuum ultraviolet probe pulses

“…Grating monochromators even allow a bandwidth reduction below the inherent width of the respective harmonic at the cost of photon flux [20,22]. Pulse broadening in the time domain due to pulse front tilting of diffracted pulses can be corrected with time compensated dual grating setups [21] preserving the pulse duration of high-order harmonics which is much shorter than that of the driving pulse [30]. However, these setups reduce the beamline transmission and increase the alignment effort of the setup.…”