Nd^(3+):α~NaYF_4单晶体的生长与光谱特性

Growth and Spectral Properties of Nd^(3+) Doped α-NaYF_4 Single Crystal

以KF为助熔剂,初始原料按照Na F:KF:YF_3:Nd F_3=30:18:47:5的摩尔比例,采用助熔剂-坩埚下降法成功生长出了优质块体Nd^(3+)掺杂α~Na YF4单晶体。XRD图谱表明,引入少量钕离子没有改变单晶体的立方相结构。测定了钕离子在晶体中的实际掺杂浓度为3.15mol%,相比初始掺杂浓度偏小,说明在单晶体中稀土离子存在着分凝现象。根据吸收图谱,在800 nm处具有最强吸收峰,最大吸收系数α和吸收跃迁截面σabs分别为0.91 cm-1和0.138×10-20cm2。在800 nm激光激发下,发射光谱在800~1500 nm范围内有三个峰,由4F_3/2能级跃迁到4I11/2能级所产生位于1052 nm处的峰值最强,测得荧光寿命为35μs。掺钕氟化钇钠晶体的光学特性表明它在中红外激光领域具有潜在的应用价值。

The bulk single crystal of Nd^3＋doped α - NaYF4 was in a molar ratio of starting material Na F：KF：YF3：Nd F3= 30 ：18 ：47 ：5 grown by an improved flux-Bridgman method using KF as flux. XRD pattern shows that the incorporation of a small amount of Nd^3＋ions did not change the cubic phase structure of the single crystal. The actual doping concentration of Nd^3＋ions in the single crystal was determined to be 3. 15mol%,which was smaller than the incorporation concentration. The results show that rare earth ions have segregation phenomenon in the crystal. According to the absorption spectrum,it can be seen that the strongest absorption peak at 800 nm. The maximum absorption coefficient α and the maximum absorption cross section σabsare respectively 0. 91 cm-1and 0. 138 × 10-20cm2. The emission spectrum has three peaks ranging from 800 nm to 1500 nm under 800 nm excitation. The strongest peak at1052 nm produced by the4F3/2level to the4I11/2level transition. The fluorescence lifetime was measured to be 35 μs. The optical properties of Nd^3＋doped NaYF4 crystal show that it has potential applications in the field of mid infrared laser.