Selective laser excitation of the luminescence of Sm/sup 3 +/ ions in lanthanum aluminum silicate glass

The structure of the inhomogeneously broadened luminescence spectra of Sm/sup 3 +/ ions in a new high-temperature LiAlSi glass is studied by selective laser excitation and real time sampling of the luminescence signal. Substantial line narrowing, the appearance of additional structure, and correlated variations in the energy of the luminescence transitions /sup 4/G/sub 5/2/..-->../sup 6/H/sub 5/2/ were detected as the wavelength of the exciting light was varied. As a result, a diagram of the positions of the Stark sublevels is constructed for various spectrally nonequivalent Sm/sup 3 +/ centers. It demonstrates continuous variation in the strength of the ligand field from center to center without the sharp jumps that usually accompany changes in the symmetry of the optical center. The shape of the homogeneously broadened profile of the /sup 4/G/sub 5/2/..-->../sup 6/H/sub 5/2/ transition is obtained at T=300K. The homogeneous width of this transition was found to be delta=19 cm/sup -1/; this is 6 times narrower than its inhomogeneous width.