Nd super(3+)-Yb super(3+) doped powder for near-infrared optical temperature sensing

Er super(3+) doped powders are generally used for fluorescence-based temperature sensing application when near-infrared lasers are the excitation sources of choice. The fluorescence of Er super(3+) is produced by nonlinear (upconversion) processes, which generate strong internal heat. Lowering the excitation power causes drastic reduction of the fluorescence signal, and as a consequence the sensor applicability of Er super(3+) doped powders becomes compromised. Here we propose the use of the downconverted fluorescence of Yb super(3+) produced by efficient energy transfer from Nd super(3+) as an alternative temperature sensing system. Our results are presented for yttrium silicate powders prepared by combustion synthesis.