Investigation of Luminescent Properties of Optical Ceramics Based on YAG and Luag Co-Activated by Yb³⁺ and Er³⁺

LuAG-based optical ceramics co-doped with Yb³⁺ and Er³⁺ ions was successfully synthesized for the first time. The optical, spectral-luminescent, and kinetic characteristics of ceramics based on Y_2.82Yb_0.15Er_0.03Al₅O₁₂ (YAG 5-Yb, 1-Er) and Lu_2.82Yb_0.15Er_0.03Al₅O₁₂ (LuAG 5-Yb, 1-Er) compositions were investigated. It is demonstrated that excitation of luminescence at a wavelength of 940 nm in YAG 5-Yb, 1-Er and LuAG 5-Yb, 1-Er ceramics results in the effective transfer of excitation radiation energy from Yb³⁺ ions to Er³⁺ ions. The energy transitions that play a pivotal role in the processes of Stokes and anti-Stokes luminescence of ceramics based on YAG 5-Yb, 1-Er and LuAG 5-Yb compositions was identified, and a schematic representation of these transitions is presented. The mutual variation of the intensity of anti-Stokes luminescence bands resulting from the transitions ²H_11/2 → ⁴I_15/2 (525 nm) and ⁴S_3/2 →⁴I_15/2 (546 nm) was observed, with regard to the power of the excitation radiation. This study demonstrates the potential of YAG 5-Yb, 1-Er and LuAG 5-Yb, 1-Er ceramics as materials for optical thermometry.