VUV and UV sources and spectroscopic applications

Extensive experimental studies of small molecules as potential 'hosts' for short wavelength (lambda less than 200 nm) energy-storage lasers have been conducted. Laser spectroscopy of the rare gas dimers and Group IIB dimers have yielded structural constants for a significant number of previously unobserved states. Also, Fano 'windows' have been observed in Ne2 in the energy region lying between v(+) = 0 and v(+) = 3 of the Ne2(+) ground state X(sup 2)sigma. Bound free emission studies of Cd2 and Zn2 have been carried out and the structural constants for the sigma-1 upper states have been determined. The growth of GaAs and GaN by photo-assisted MOCVD has also been demonstrated. Gallium arsenide has been grown epitaxially at temperatures as low as 450 C by illuminating the surface with ArF (193 nm) radiation. Also, polycrystalline GaN (preferentially oriented (100)) has been grown on GaAs and sapphire at temperatures as low as 700 C and at growth rates exceeding 2 micrometers/hour.