Color-tunable upconversion luminescence of Er3+ in oxyfluoride nano-glass-ceramics

Tuning color output and enhancing upconversion emission of Er3+ ions in transparent sodium lutetium fluoride glassceramics in bulk and optical fibers, by adjusting the Yb3+ doping level and the excitation power, has been demonstrated. The addition of Yb3+ enhances the UC emission and tunes the color from green to yellow due to an increase of the red-to-green intensity ratio. Moreover, the relative emission intensities of blue, green, and red emissions can be changed by controlling the excitation power which tunes the color from yellow to green.