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Published on: April 16, 2017
Valley-to-peak intensity ratio thermometry based on the red upconversion emission of Er3+
Abstract:
Upon 976 nm diode laser excitation, the temperature dependence of the red upconversion emission of Er3+ in CaWO4:Yb3+/Er3+ phosphor was studied from 298 to 478 K. The spectrum was verified to consist of two Stark components originating from two Stark sublevels of 4F9/2 excited state to 4I15/2 ground state of Er3+. The valley-to-peak intensity ratio (VPR) of this double-peak spectrum was found to increase linearly with the rise of temperature. The maximum relative sensitivity of this VPR method was obtained to be about 0.20% K-1 at 298 K. Moreover, a study on the power dependence was also performed, suggesting that VPR method is immune to the pump power and is thus suitable for monitoring the temperature.

