Monitoring of laser heating temperature in laser spectroscopic measurements

During laser spectroscopic measurement, a part of laser energy will be converted into heat in the processes of excitation and light emission. Temperature monitoring can help to evaluate such nonradiative process. Upconversion luminescence of phosphor Y2O3:Er,Yb under laser excitation at 980 nm was investigated in this work. Point temperature of the phosphor was monitored using the fluorescent intensity ratio (FIR) technology. Laser induced temperature rising was identified by comparison with a theoretically ideal temperature calibration function: lnR = 3.1738-1167/T. The monitored temperature of laser heating rises monotonically with increasing laser power. Circumstances around heating point will modify the calibration function, but the linear slope of lnR ~ 1/T is constant.