Crystallization kinetics and enhanced Bi NIR luminescence of transparent silicate glass-ceramics containing Sr2YbF7 nanocrystals

Bismuth-doped glasses and crystals have been widely investigated due to their intriguing potential applications in superbroadband fiber amplifier and lasers in new NIR spectral range. However, few reports have been devoted so far to bismuth-doped transparent glass-ceramics. Here, this work reports on bismuth-doped silicate glasses and glass-ceramics, which were prepared by melt-quenching and consequent annealing processes, respectively. On the basis of the analyses on crystallization kinetics, nucleation and growth rate of crystalline phase can be modulated and Sr2YbF7 nanophase can, therefore, be precipitated uniformly inside the glass matrix in a controlled way to maintain proper transparence especially in optical telecommunication windows. Once the nanophase comes into being, enhanced bismuth NIR luminescence can be observed by more than 40 times upon excitation of 470nm. Similar enhancement can appear upon different excitation schemes and the mechanism is discussed accordingly. Such Bi doped transparent glass-ceramics with improved luminescence efficiency might find application in fiber lasers for future optical fiber communication.