The Ho3＋/yb3＋ co-doped a-NaYF4 single crystal was grown successfully for the first time by a modified Bridgman method in which KF was used as assisting flux and a large temperature gradient （70-90℃ /cm） of solid-...The Ho3＋/yb3＋ co-doped a-NaYF4 single crystal was grown successfully for the first time by a modified Bridgman method in which KF was used as assisting flux and a large temperature gradient （70-90℃ /cm） of solid-liquid interface was adopted. Upconversion emissions at green -544 nm, red -657 and -751 nm were obtained under 980 nm laser diode excitation. The intensity at -544 nm was much stronger than those of -657 and -751 nm. The mechanisms of the upconversion emissions were investigated by studying the relationship between the upconversion intensity and pump power. The optimized Yb3＋ concentration was about 8.08moi% when Ho3＋ concentration was hold at about 1.0mol%. The results showed that Ho3＋/yb3＋ doped α-NaYF4 single crystal was a possible candidate upconversion material for the green solid-state laser.展开更多
基金This work was supported by the National Natural Science Foundation of China （No.51472125, No.51272109） and K. C. Wong Magna Fund in Ningbo University.
文摘The Ho3＋/yb3＋ co-doped a-NaYF4 single crystal was grown successfully for the first time by a modified Bridgman method in which KF was used as assisting flux and a large temperature gradient （70-90℃ /cm） of solid-liquid interface was adopted. Upconversion emissions at green -544 nm, red -657 and -751 nm were obtained under 980 nm laser diode excitation. The intensity at -544 nm was much stronger than those of -657 and -751 nm. The mechanisms of the upconversion emissions were investigated by studying the relationship between the upconversion intensity and pump power. The optimized Yb3＋ concentration was about 8.08moi% when Ho3＋ concentration was hold at about 1.0mol%. The results showed that Ho3＋/yb3＋ doped α-NaYF4 single crystal was a possible candidate upconversion material for the green solid-state laser.
