[OPTICAL REVIEW Vol. 7, No. 2 (2000) 101-111]
Spectroscopy and Continuous Wave Near-Infrared Stimulated Emission of New Yttrium Gallium Garnet {Y3} [Y, Ga](Ga3) O12:Nd3+ (YGaO3:Nd3+)
Alexander A. KAMINSKII,1,* Ken-ichi UEDA,2,** Doyle TEMPLE,3 Galina A. BOGOMOLOVA,1 Jose GARCIA-SOLE4 and Daniel JAQUE4
1Institute of Crystallography, Russian Academy of Sciences, Leninsky prospekt 59, 117333 Moscow, Russia, 2Institute for Laser Science, University of Electro-Communications, 1-5-1, Chofugaoka, Chofu, Tokyo, 182-8585 Japan, 3Department of Physics, Hampton University, Hampton, Virginia 23688, U.S.A., 4Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid, Spain
(Received November 23, 1999; Accepted December 22, 1999)
Detailed spectroscopic investigations are made for a new laser material, a Nd3+-ion doped YGaO3 garnet crystal with disordered structure, grown from the physicochemical Y2O3-Ga2O3 system with sesquioxide relation close to 1:1. Following absorption and luminescence spectral analyses, the Stark splitting of the 4F3/2 and 4IJ' manifolds of Nd3+ activators are measured with high accuracy. Between the Stark levels of two near-infrared laser channels (4F3/2→4I11/2 and 4F3/2→ 4I13/2) low-threshold continuous wave stimulated emission was excited at 300 K. Some spectroscopic characteristics, such as radiative lifetime of the initial laser 4F3/2 state, intermanifold and inter-Stark luminescence branching ratios, linewidths, spontaneous transition probabilities and peak and effective cross-sections of induced transitions are also determined. These parameters are necessary for a theoretical description of the functional properties of Nd3+:YGaO3 lasers.
Key words : solid-state lasers, new laser, yttrium gallium garnet, Nd3+ ion, disordered laser crystal mass fractal, surface fractal, combined fractal, self-similarity, power law, fractal dimension