Spectroscopic properties of Er3+ in a oxyfluoride glass and upconversion and temperature sensor behaviour of Er3+/Yb3+-codoped oxyfluoride glass

Spectroscopic properties of Er3+-singly doped SiO2––BaF2–ZnF2 glass have been investigated on the basis of the Judd–Ofelt theory. Upconversion emissions in Er3+/Yb3+-codoped SiO2–BaF2–ZnF2 glass have been observed under 980 nm excitation. The temperature dependence of fluorescence intensity ratio corresponding to the two thermally coupled levels (2H11/2, 4S3/2) has been studied and it is concluded based on the results that the method can be possibly applied for temperature sensing.