Optical spectroscopy of Cr3+-doped transparent nano-glass ceramics for lifetime-based temperature sensing

Transparent bulk glass ceramic containing Cr3+:LiGa5O8 nanoparticles was fabricated as an alternative for monocrystal to explore the possible application in fluorescence lifetime-based temperature sensing. Such glass ceramic exhibited deep-red luminescence upon the excitation of the wide wavelength range of visible light. Impressively, the Cr3+ lifetime dramatically decreased from 2.45 to 0.22 ms with the temperature increasing from 293 to 563 K, owing to the competition of radiation transitions from the thermally coupled E-2 and T-4(2) excited states. A two-level kinetic model was adopted to interpret this temperature-dependent luminescence of Cr3+, which gave a highest temperature sensitivity of 1.15% K-1. (C) 2015 Optical Society of America