Related Experiment Video
Updated: Mar 9, 2026

Molecular Beam Mass Spectrometry With Tunable Vacuum Ultraviolet VUV Synchrotron Radiation
Published on: October 30, 2012
Vacuum-ultraviolet frequency-modulation spectroscopy
U Hollenstein1, H Schmutz1, J A Agner1
1Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland.
Abstract:
Frequency-modulation (FM) spectroscopy has been extended to the vacuum-ultraviolet (VUV) range of the electromagnetic spectrum. Coherent VUV laser radiation is produced by resonance-enhanced sum-frequency mixing (νVUV=2νUV+ν2) in Kr and Xe using two near-Fourier-transform-limited laser pulses of frequencies νUV and ν2. Sidebands generated in the output of the second laser (ν2) using an electro-optical modulator operating at the frequency νmod are directly transferred to the VUV and used to record FM spectra. Demodulation is demonstrated both at νmod and 2νmod. The main advantages of the method compared to VUV absorption spectroscopy are its background-free nature, the fact is that its implementation using table-top laser equipment is straightforward and that it can be used to record VUV absorption spectra of cold samples in skimmed supersonic beams simultaneously with laser-induced-fluorescence and photoionization spectra. To illustrate these advantages, we present VUV FM spectra of Ar, Kr, and N2 in selected regions between 105000 cm-1 and 122000 cm-1.
Related Concept Videos
Ultraviolet and Visible (UV–Vis) Spectroscopy: Overview
UV–Vis Spectrometers
UV–Vis Spectroscopy: Molecular Electronic Transitions
UV–Vis Spectroscopy: Woodward–Fieser Rules
UV–Vis Spectrum
The UV–Vis spectrum of a molecule is the plot of its absorbance versus wavelength. The plot is drawn by taking molar...
IR Spectroscopy: Molecular Vibration Overview
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...

