Non-invasive temperature sensors based on optical thermometry techniques,such as fluorescence lifetime and fluorescence intensity ratio(FIR)technique,have recently attracted considerable attention [1].Fluorescence intensity ratio(FIR)technique is regarded as a very promising approach for temperature sensing because it can reduce the dependence on measurement conditions and improve sensing accuracy 3]..Er3+ ion possessing two thermally coupled energy levels(TCEL)plays a key role in the study of FIR-based temperature sensors [2-4].In this work,Sr2YbF7:Er3+ glass-ceramics were successfully fabricated by melt-quenching technique for the first time.Structural and up-conversion luminescent properties of Sr2YbF7:Er3+ glass-ceramics(mcluding precursor glasses(PG)and heat-treated glass-ceramics(GC730 and GC750))were investigated systemically by XRD,HRTEM,and a series of spectroscopy methods,including FIR technique(shown in Fig.1).Under 980 nm excitation with power density of 130 mW/mm2,short wavelength up-conversion spectra of the GC750 sample were obtained at different temperatures from 300 K to 500 K.From the values of FIR and SR,it can be seen that the temperature sensitive FIR of Sr2YbF7:Er3+ nanocrystals surrounding oxide glass matrix makes Sr2YbF7:Er3+ glass-ceramics favorable for application in the optical temperature sensor.