Ultra-short-pulse high-average-power megahertz-repetition-rate coherent extreme-ultraviolet light source

Abstract

High harmonic generation (HHG) enables coherent extreme-ultraviolet (XUV) radiation with ultra-short pulse duration in a table-top setup. This has already enabled a plethora of applications. Nearly all of these applications would benefit from a high photon flux to increase the signal-to-noise ratio and decrease measurement times. In addition, shortest pulses are desired to investigate fastest dynamics in fields as diverse as physics, biology, chemistry and material sciences. In this work, the up-to-date most powerful table-top XUV source with 12.9 ± 3.9 mW in a single harmonic line at 26.5 eV is demonstrated via HHG of a frequency-doubled and post-compressed fibre laser. At the same time the spectrum supports a Fourier-limited pulse duration of sub-6 fs in the XUV, which allows accessing ultrafast dynamics with an order of magnitude higher photon flux than previously demonstrated. This concept will greatly advance and facilitate applications of XUV radiation in science and technology and enable photon-hungry ultrafast studies.

Table-top interferometry on extreme time and wavelength scales

“…Thus, the transform-limited XUV pulse length derived from the measurement is σ XUV = ∆τ/ √ 2 = 5.67 fs. Note that this is in excellent agreement with simulations of the HHG phase matching window 39 and the single-atom response 40 , resulting in an XUV pulse duration of < 6 fs 33 .…”

“…Such sources can provide significantly higher repetition rates than the currently operating free-electron lasers based on superconducting linear accelerators 31 and offer very high temporal resolution due to the intrinsically small timing jitter 32 . Here we use a high harmonic source, which is conceptually similar to the one presented in 33 , but operating at a reduced repetition rate of 100 kHz. A 20 W average power Yb-fiber laser providing 250 fs pulses at 1030 nm is frequency doubled in a 1 mm thick BBO crystal.…”

High-power fiber laser with real-time mode switchability

“…Fiber lasers have already found a wide variety of applications ranging from scientific research and medical treatment to industrial processing [1][2][3][4][5][6][7][8] , owing to their outstanding characteristics of high-power capability, system simplicity, easy thermal management, etc. [6] .…”

A Solar-Blind Ultraviolet Photodetector With Graphene/MgZnO/GaN Vertical Structure

“…Semiconductor solar-blind UV detectors have attracted widespread attention from researchers and can be applied in many fields such as spatial data transmission, discharge detection in substations, etc (Xie et al, 2013;Xu et al, 2019;Klas et al, 2021). Among them, MZO, as one of the most common solar-blind UV wide band gap semiconductor materials (Zheng et al, 2015), has a continuously adjustable band gap width of 3.3-7.8 eV, and has the advantages of low defect density, high radiation resistance (Hou et al, 2011;Jyun-Yi et al, 2015;Tian et al, 2016;Hu and Kai, 2017).…”