2 μm Emission of Ho3+-doped fluorophosphate glass sensitized by Yb3+

Two micrometer emission of Ho3+-doped new fluorophosphate glass sensitized by Yb3+ 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 Yb3+/Ho3+ codoped fluorophosphate glass, the predicted spontaneous transition probability and emission cross-section of Ho3+:5I7→5I8 reaches 73.54 s−1 and 4.66 × 10−21 cm2 , respectively, are much higher than other reported glasses. Larger product of emission cross-section (σem) and radiative lifetime (τrad) in the prepared glass shows the prepared glass is expected to be better laser material. In addition, the σem and maximum gain coefficient of Ho3+ in Yb3+/Ho3+ codoped fluorophosphate glass is 12.02% and 12.12% larger than those of Ho3+ singly-doped sample, respectively. The results suggest Yb3+/Ho3+ fluorophosphate glass is a good candidate for efficient 2 μm laser.