THE UP-CONVERSION LUMINESCENCE OF TM3-CERAMICS DOPED WITH YB3+ UNDER INFRARED EXCITATION( IN GLASS)

A detailed study of the spectroscopic properties of the PbF2 + GeO2 WO3: YbF3, TmF3 glass ceramics under infrared excitation (966 nm) is p erformed. The absorption, emission, excitation spectra, luminescence d ecay times, and up-conversion efficiency are measured. The up-conversi on of infrared into violet (363 nm), blue (451 and 478 nm), and red (6 80, 698, and 779 nm) is observed for Tm3+ ions in the sample. The up-c onversion processes involve a two-photon and a three-photon absorption for the red and blue emissions (478 nm). A four-photon process happen s for violet and another blue emissions (451 nm). In addition, the up- conversion emission spectra of violet, blue, and red bands of Tm3+ ion s are obtained in the range of 12 to 320 K. It is found that the proba bility of energy transfer between Yb3+ and TM3+ ions depends on temper ature. By a comparative method, absolute fluorescence efficiencies of 10(-6) and 5.86 x 10(-3) are obtained for the dominant blue (478 nm) a nd red (779 nm) up-conversions when the sample is excited by 966 nm li ght with an absorbed intensity of 16.5 mW/cm2 at room temperature.