Effect of temperature on the radiative and non-radiative processes in LLCG:Cr3+, LLCG:Nd3+, and the Cr-to-Nd energy transfer processes in LLGG:Cr3+, Nd3+ crystals were investigated in detail. Data collected includes absorption, luminescence, excitation and response to pulsed excitation measurements. The radiative lifetime of Cr3+ ion in both LLGG:Cr3+ and LLGG:Cr3+, Nd3+ crystals was found to be temperature dependent, hence the Cr-to-Nd energy transfer in the latter crystal was also temperature dependent. The lifetime and the integrated luminescence intensity of 1.06 mu m luminescence show the same temperature dependent indicating that radiative lifetime of Nd3+ ion in LLGG crystal is temperature independent. However the temperature dependence of 1.06 mu m emission of Nd3+ ion in LLGG:Cr3+, Nd3+ crystal was found to be different than that of LLGG:Nd3+ when this emission was excited via Cr3+ ions. A model that takes into account the variations of both radiative and non-radiative decay probabilities of Cr3+ ion with temperature was presented to explain these phenomena and the temperature dependence of Cr3+-to-Nd3+ energy transfer processes in LLCG:Cr3+, Nd3+. (C) 2000 Published by Elsevier Science B.V.