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The upconversion luminescence and near infrared luminescence of the Er 3 + ions in transparent oxyfluoride glassceramics containing Sr F 2 nanocrystals have been investigated. The formation of Sr F 2 nanocrystals in the glassceramics was confirmed by x-ray diffraction. The oscillator strengths for several transitions of the Er 3 + ions in the glass and glassceramics have been obtained and then the Judd-Ofelt parameters were determined. The split near infrared emission peaks of the Er 3 + ions in the glassceramics can be observed because the Er 3 + ions have been incorporated into crystalline environment of the Sr F 2 nanocrystals. The upconversion luminescence intensity of Er 3 + ions in the glassceramics increased significantly with the increasing crystallization time. The transition mechanisms of the green and red upconversion luminescence have been ascribed to two-photon process and the blue upconversion luminescence to three-photon process.
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