2 μm Emission of Ho 3+-doped fluorophosphate glass sensitized by Yb 3+

Abstract

Two micrometer emission of Ho 3+-doped new fluorophosphate glass sensitized by Yb 3+ upon excitation of a conventional 980 nm laser diode is reported. Based on the measured absorption spectra, the Judd–Ofelt parameters and radiative properties were calculated and discussed. For Yb 3+/Ho 3+ codoped fluorophosphate glass, the predicted spontaneous transition probability and emission cross-section of Ho 3+: 5I 7→ 5I 8 reaches 73.54 s −1 and 4.66 × 10 −21 cm 2 , respectively, are much higher than other reported glasses. Larger product of emission cross-section ( σ em ) and radiative lifetime ( τ rad ) in the prepared glass shows the prepared glass is expected to be better laser material. In addition, the σ em and maximum gain coefficient of Ho 3+ in Yb 3+/Ho 3+ codoped fluorophosphate glass is 12.02% and 12.12% larger than those of Ho 3+ singly-doped sample, respectively. The results suggest Yb 3+/Ho 3+ fluorophosphate glass is a good candidate for efficient 2 μm laser.