Optical temperature sensing through extraordinary enhancement of green up-conversion emissions for Er-Yb-Mo:Al2O3

The extraordinary enhancement of green up-conversion emissions originated from the H-2(11/2) -> I-4(15/2) and S-4(3/2) -> I-4(15/2) transitions is obtained for the Er-Yb-Mo:Al2O3 with a 976 nm laser diode excitation. It indicates that such green enhancement arises from the high excited state energy transfer with (IF7/2)-F-2, T-3(2)> state of the Yb3+-MoO42- dimer to the F-4(7/2) level of Er3+. Fluorescence intensity ratio (FIR) technique based on the green up-conversion emissions of the Er-Vb-Mo:Al2O3 has been studied as a function of temperature. With an excitation power of 2 mW, the maximum of sensitivity and temperature revolution is approximately 0.0051 K-1 and 0.3 K in the range of 294-973K, respectively. The Er-Yb-Mo:Al2O3 with intense green up-conversion emissions, a higher operating temperature and revolution indicates that it is a promising material for application in optical temperature sensing. (C) 2012 Elsevier B.V. All rights reserved.