Alignment and characterization of the two-stage time delay compensating XUV monochromator

TL;DR

This paper details the design and implementation of a two-stage time delay compensating XUV monochromator that produces short, wavelength-selected XUV pulses with high stability, suitable for pump-probe experiments.

Contribution

It introduces a novel two-stage monochromator with precise alignment and stability features for generating short XUV pulses in the 3-50 eV range.

Findings

XUV pulses as short as 12 fs demonstrated

Stable beamline enables automatic energy scanning

Generation of IR-assisted sidebands in argon photoionization

Abstract

We present the design, implementation and alignment procedure for a two-stage time delay compensating monochromator. The setup spectrally filters the radiation of a high-order harmonic generation source providing wavelength-selected XUV pulses with a bandwidth of 300 to 600~meV in the photon energy range of 3 to 50~eV. XUV pulses as short as $12\pm3$~fs are demonstrated. Transmission of the 400~nm (3.1~eV) light facilitates precise alignment of the monochromator. This alignment strategy together with the stable mechanical design of the motorized beamline components enables us to automatically scan the XUV photon energ in pump-probe experiments that require XUV beam pointing stability. The performance of the beamline is demonstrated by the generation of IR-assisted sidebands in XUV photoionization of argon atoms.