Evaluation of rare earth doped silica sub-micrometric spheres as optically controlled temperature sensors

We report on the evaluation of rare earth (Er3þ, Eu3þ, and Tb3þ ions) SiO2 sub-micrometric spheres as potential optically controllable temperature sensors. Details about fabrication, optical manipulation and spectroscopic characterization of the sub-micrometric spheres are presented. The fluorescence properties of the micros-spheres in the biological range (25–60 C) have been systematically investigated. From this systematic study, the thermal resolution potentially achieved in each case has been determined and compared to previous works