Speaker
Description
Ultracold helium nanodroplets provide an ideal matrix for gas-phase vibrational spectroscopy, reducing thermal broadening and spectral congestion while unperturbed significantly by solvent effects and interactions with dopant ions. In the experiment, ions are embedded in a helium droplet and irradiated with a burst-mode infrared free electron laser (FEL). Resonant absorption of photons from the FEL pulse train by the ion dissipates energy to the surrounding helium, causing evaporation and detection of the bare ion as as a function of wavelength and generating low noise spectra. While the majority of previous FEL ultracold helium experiments have utilised a single FEL beam (one-colour), there exist may opportunities to use one-colour split-pump and two-colour beams for novel molecular detection and probing experiments. Here we explore the experimental design and implementation for controlling split pump and simultaneous two-colour FEL experiments with adjustable spatial and temporal pulse overlap using second-harmonic generation at near to far IR.
