Knowledge Bank

We report the extension of the ring dye laser to short wavelengths using a new BBO crystal and other optics. Previously, using $LilO3$ as a doubling crystal, the obtainable UV was restricted to the 295-330 nm region. In our initial investigations, we have obtained photons in the 285-295 nm region and demonstrated excellent tunability and stability over this range. The new source has already allowed us to record the fully resolved spectrum of aniline (293.9 nm) at a lifetime-limited resolution of 20 MHz. By lineshape fitting of single rovibronic lines, we obtain a lifetime of 8 ns, in good agreement with other studies. Extremely high resolution spectroscopic methods have demonstrated that we can observe single molecular eigenstates (ME) which enable the elucidation of the role of rotational effects on intramolecular radiationless $transitions.2$ The vibrational predissociation (VP) of small, isolated van der Waals clusters have received considerable attention concerning the dynamics of the radiationless intramolecular vibrational energy redistribution (IVR) and VP processes. Here, we present a static spectroscopic study of the aniline-Ar complex in an attempt to elucidate the excited state IVR and VP dynamics at the ME level.