HgIn photoassociation, bound-bound transitions, and excimer emission

Laser excitation of In atoms at the 6 2S1/2–5 2P1/2 atomic resonance transition wavelength of 410.3 nm in the presence of Hg vapor produces several types of emission features: HgIn excimer satellites on the red wings of the In resonance fluorescence transitions at 410.3 and 451.1 nm, bound-bound HgIn molecular fluorescence at 499 and 522 nm resulting from photoassociation of In(6 2S1/2) with Hg(6 1S0), and UV atomic fluorescence from the In(5 2D) states that lie at energies above the In(6 2S1/2–5 2P1/2) excitation. These various spectral features are interpreted in terms of a proposed HgIn potential-energy level diagram with additional information from measured excited-state lifetimes and the power dependence of the laser excitation at 410.3 and 522 nm. Direct excitation of the 499 and 522 nm HgIn bound-bound transitions also produces emission at 410.3 and 451.1 nm resulting from collisional dissociation of the excited HgIn states.