High resolution molecular physics studies using a laser-based tunable XUV source at 107 resolving power

At the Laser Centre Vrije Universiteit, a tunable and narrowband laser-based source of extreme ultraviolet (XUV) radiation was developed using non-resonant third harmonic generation (THG) of powerful laser pulses in the ultraviolet range. The laser source is either a commercial or modified pulsed dye laser (grating-based) or a pulsed-dye-amplifier, which is injection seeded by the output of a continuous wave ring-dye laser or a Ti:sapphire laser. This system opens the possibility to perform spectroscopic research at wavelengths 70-110 nm at a resolution unattainable with classical light sources. Particularly in the range 90-110 nm a source bandwidth of 0.01 cm−1 can be employed. Examples of gas-phase molecular beam spectroscopic studies on diatomic molecules, such as H2, N2 and CO will be presented. Another feature of Q-switch based XUV laser sources is the possibility to perform multi-step multi-photon experiments in molecules, uncovering otherwise inaccessible states.