【摘要】 以KF作为助熔剂,采用固液界面温度梯度（70⁹0℃/cm）,通过改进的助熔剂-坩埚下降法从NaF-YF₃熔体系统中生长出了Ho³⁺/Yb³⁺离子双掺杂的α-NaYF₄单晶体.在980 nm激光泵浦下可以观察到544 nm的上转换绿光和657和751 nm的上转换红光.上转换的绿光强度明显强于上转换红光.通过测量泵浦功率和上转换光的强度之间的关系研究了上转换发光的机理.当Ho³⁺的掺杂浓度保持为1.0mol%的情况下,Yb³⁺的浓度为8.08mol%时上转换强度最强.更多还原

【Abstract】 The Ho³⁺/Yb³⁺ co-doped α-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 at⁵44 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 about8.08mol%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.更多还原