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

Few-femtosecond extreme-ultraviolet pulses fully reconstructed by a ptychographic technique

“…Indeed, with monochromators based on a single-grating working in an off-plane geometry only XUV pulses with a time duration of few tens of fs have been reported so far [37,38]. Comparable results in terms of time duration can be obtained with a TDCM [39], which further allows for the generation of shorter pulses, of the order of 10 fs [40] or less [6].…”

“…Furthermore, based on a cross-correlation picture, we will introduce a simple analytical expression that can be used to obtain a first rough estimation of the XUV pulse duration. Finally, we will compare the cross-correlation model [40,43] with the ePIE reconstruction, discussing the advantages of the latter.…”

Time-resolved high-harmonic spectroscopy of ultrafast photoisomerization dynamics

“…However, we observed that the ring opens at around 500 fs upon excitation from the HOMO to the 3p x -Rydberg state via two-photon absorption (2PA) using 3.1 eV photons, which is much slower than that observed in case of 1PA. In this experiment, we employed time-resolved photoelectron spectroscopy (TR-PES) using an isolated single-order harmonic at 29.5 eV [28] that was selected using a time-delay compensated monochromator [41][42][43][44]. Thus, another motivation of the present study is to confirm the delayed ring-opening of CHD upon 2PA by a spectroscopic method other than TR-PES; therefore, in this study, we employed TR-HHS.…”

Compression of Extreme-Ultraviolet Ultrashort Pulses by Grating Configurations

“…The first grating is demanded to perform the spectral selection on an intermediate slit; the second grating compensates for the pulse-front tilt of the diffracted beam by equalizing the length of the optical paths, giving a temporal resolution much higher than the single-grating design. Double-grating instruments have been demonstrated to be very effective for HHs, with time resolution well below 10 fs [43][44][45][46][47]. The choice between the two options has to be performed as a trade-off between efficiency and throughput, which are maximized in the single-grating design, and temporal resolution, which is maximized in the doublegrating design.…”