Extreme Ultraviolet-Excited Time-Resolved Luminescence Spectroscopy Using an Ultrafast Table-Top High-Harmonic Generation Source

TL;DR

This paper introduces a novel table-top XUV spectroscopy setup capable of measuring time-resolved luminescence with femtosecond resolution, enabling detailed study of XUV-driven phenomena in solid materials.

Contribution

It presents a new experimental platform combining high-harmonic generation with time-resolved luminescence spectroscopy for the first time.

Findings

Time-resolved XEOL measurements of three materials

Identification of decay mechanisms post XUV excitation

Demonstration of femtosecond temporal resolution in XUV luminescence

Abstract

We present a table-top extreme ultraviolet (XUV) beamline for measuring time- and frequency-resolved XUV excited optical luminescence (XEOL) with additional femtosecond-resolution XUV transient absorption spectroscopy functionality. XUV pulses are generated via high-harmonic generation using a near-infrared pulse in a noble gas medium, and focused to excite luminescence from a solid sample. The luminescence is collimated and guided into a streak camera, where its spectral components are temporally resolved with picosecond temporal resolution. We time-resolve XUV excited luminescence and compare the results to luminescence decays excited at longer wavelengths for three different materials : (i) sodium salicylate, an often used XUV scintillator, (ii) fluorescent labeling molecule 4-carbazole benzoic acid (CB), and (iii) a zirconium metal oxo-cluster labeled with CB, which is a photoresist candidate for extreme-ultraviolet lithography. Our results establish time-resolved XEOL as a new technique to measure transient XUV-driven phenomena in solid-state samples, and identify decay mechanisms of molecules following XUV and soft-X-ray excitation.