Green up-conversion emissions and optical thermometry of Er<sup>3+</sup> doped borosilicate glass

Abstract

The green up-conversion emissions corresponding to the 2 H11/2→4I15/2 and 4S3/2→4I15/2 transitions of the Er 3 + doped borosilicate glass were recorded, using a 978-nm semiconductor laser diode as an excitation source. The fluorescence intensity ratio (FIR) of the green up-conversion emissions at about 524 and 550 nm was studied as a function of temperature over the temperature range of 296 to 723 K. The maximum sensitivity and the temperature resolution derived from the FIR of the green up-conversion emissions were approximately 0.0038 K−1 and 0.2 K, respectively. It was demonstrated that the prototype optical temperature sensor based on the FIR technique from the green up-conversion emissions in the Er 3 + doped borosilicate glass plays a major role in temperature measurement.