The enhanced up-conversion green by Yb-Mn dimer in NaBiF4:Yb3+/Er3+/Mn2+ for optical fiber temperature sensor

Through doping Mn2+ into the NaBiF4:Yb3+/Er3+, it can be achieved that NaBiF4 :Yb3+/Er3+/Mn2+ possess superior temperature sensing performance and application in temperature optical fiber sensing on the premise of enhancing the green emission upon the 980 nm excitation. The effect of Mn2+ content on the phase and luminescence of NaBiF4:Yb3+/Er3+/Mn2+ is investigated by X-ray diffraction (XRD) and fluorescence spectrophotometer characterization. The up-conversion (UC) green emission intensity is enhanced by 3 times by Mn2+ doping. The Yb3+-Mn2+ dimer is introduced to clarify the mechanism of UC red and green emission enhancement, where involved in is three-photon process. Moreover, the optical thermometric behaviors of the synthetic compounds are analyzed according to the fact that Er3+ processes a couple of green emission levels 2H11/2 and 4S3/2, and the maximum Sa (absolute sensor sensitivity) reaches 0.00559 K−1. The preliminary design and application of NaBiF4:Yb3+/Er3+/Mn2+ as a probe in the temperature optical fiber sensor has been carried out, suggesting that NaBiF4: Yb3+/Er3+/Mn2+ is expected to be a kind of promising material for non-contact optical thermometer.