Transparent Ho3+-doped nano-glass-ceramics for efficient infrared emission

Abstract

We developed transparent $3.5\mathrm{mol}\%$ ${\mathrm{Ho}}^{3+}$ -doped oxyfluoride nano-glass-ceramics, where the ${\mathrm{Ho}}^{3+}$ -dopants dissolve in the $6\mathrm{nm}$ diameter $\beta \text{-}\mathrm{Pb}{\mathrm{F}}_2$ nanocrystals. The cubic site of ${\mathrm{Ho}}^{3+}$ and a low vibration frequency of its $\mathrm{Pb}{\mathrm{F}}_2$ environment result in an intense and $50\mathrm{nm}$ broad emission band ${}^{5}I_6\to {}^{5}I_8$ of ${\mathrm{Ho}}^{3+}$ at $1.2\mu \mathrm{m}$ with a temperature independent lifetime of $1.6\mathrm{ms}$ . Another $40\mathrm{nm}$ broad emission band ${}^{5}F_5\to {}^{5}I_6$ at $1.47\mu \mathrm{m}$ with a lifetime of $24\mu \mathrm{s}$ was also excited, the lifetime of this band increased to $60\mu \mathrm{s}$ at $77\mathrm{K}$ . These two bands have potential application for optical amplification in telecommunications.