Spectroscopic characteristics of YSGG:Cr,Ho, YSGG:Cr, Tm and YSGG:Cr,Tm,Ho

In this paper some spectroscopic properties of Y₃Sc₂Ga₃O₁₂ (YSGG):Cr,Ho, YSGG:Cr,Tm and YSGG:Cr,Tm,Ho are presented. The three lowest energetic manifolds of Ho³⁺ and Tm³⁺ in YSGG have been determined at 10 K. Time-resolved fluorescence build-up and decay of the laser active ions was measured in three crystals with different dopant concentrations. The transitions investigated were⁵I₇ ⁵I₈ for Ho³⁺ near 2000 nm and³H₄ ³H₆ for Tm³⁺ near 1800 nm. The data found on time-resolved fluorescence and energy level positions are useful for the discussion of the energy transfer characteristics of the system.