title: 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 of4F9/2excited state to4I15/2ground 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-1at 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.
authors.forename: Leipeng
authors.initials: L
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Longjiang
authors.initials: L
authors.lastname: Zheng
authors.forename: Feng
authors.initials: F
authors.lastname: Qin
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhou
authors.forename: Zhang
authors.initials: Z
authors.lastname: Liang
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Zhang
authors.forename: Wenwu
authors.initials: W
authors.lastname: Cao