SPECTROSCOPY AND LASER ACTION OF ANISOTROPIC SINGLE-CENTERED LIKYF5-ND3+ CRYSTALS GROWN BY THE HYDROTHERMAL METHOD

Spectroscopic investigations are made on new laser monoclinic single-centered LiKYF5:Nd3+ crystals grown by the hydrothermal method. Stark levels of its activator ions for 37 (2s+1)L(J) manifolds lying up to approximate to 40000 cm(-1) are established from luminescence and absorption spectra at 7 K. Using a new set of reduced-matrix elements for electric-dipole 4f(3)-4f(3) transitions the intensity characteristics for LiKYF5:Nd3+ are calculated including phenomenological Judd-Ofelt parameters Omega(t), intermanifold absorption line strengths, as well as the radiative lifetime of the initial laser state F-4(3/2) and branching ratios originated for its IR emitting channels. The kinetics of luminescence from four metastable states F-2(7)(5/2), D-4(3/2), P-2(3/2), and F-4(3/2) as function of Nd3+-ion concentration and temperature are measured. Room-temperature pulse, cw, and quasi-cw stimulated emission of Nd3+ ions at two generating F-4(3/2) --> I-4(11/2) and F-4(3/2) --> I-4(13/2) channels under Xe-flashlamp and laser-diode pumpings are obtained. All observed induced inter-Stark transitions are identified.