Tunable pulsed vacuum ultraviolet light source for surface science and materials spectroscopy based on high order harmonic generation

We report here the development of a tunable vacuum ultraviolet light source , providing subpicosecond pulses over the wavelength range from 114 (simila r to 11 eV) to 32 nm (similar to 39 eV), designed for surface science exper iments. The source is based on high order harmonic generation. The experime ntal setup is described in detail and the harmonic yield as a function of t he gas type (xenon or argon) is compared with theoretical descriptions. We address in particular the tunability of the source, desirable for surface s cience applications. Absolute characterization of the harmonic yield has al so been performed and validated with time-resolved fluorescence measurement s. The results are extremely promising, with intensities of similar to 10(1 0) photons/s, with regard to the use of this coherent source for surface sc ience and spectroscopy. (C) 2001 American Institute of Physics.