多坩埚温度梯度法生长Dy^(3+)∶LaF_(3)晶体及发光特性

Luminescence Properties of Dy^(3+)Doped Lanthanum Fluoride Crystal by Multi-crucible Temperature Gradient Technology

采用多坩埚温度梯度法(Multi-crucible temperature gradient technology,MC-TGT)制备了Dy^(3+)掺杂氟化镧(Dy^(3+)∶LaF_(3))晶体。通过电感耦合等离子体发射光谱仪、透射光谱、吸收光谱、荧光光谱等手段对Dy^(3+)在LaF_(3)晶体中的实际掺杂浓度、中红外透过光谱、可见光波段光谱特性等进行了研究。实验结果表明,Dy^(3+)在LaF_(3)晶体中的分凝系数约为0.8;格位浓度随着Dy^(3+)掺杂浓度提高而增加,2%Dy∶LaF_(3)晶体中的格位浓度达5.90×10^(20)ions·cm^(-3)。在1%Dy∶LaF_(3)晶体中,采用400 nm光激发,发光中心波长位于601 nm的发射谱带强度最大,位于511 nm的发射峰最宽,半高宽达152 nm;改用450 nm光激发,最强发射峰移至677 nm,最宽发射峰位于568 nm处。提高Dy^(3+)掺杂浓度到2%,采用400 nm或450 nm光激发,发光中心波长均位于478 nm和571 nm。在透射光谱2.5~9μm范围内,Dy∶LaF_(3)晶体(厚度为0.96 mm)红外波段透过率达85%以上。Dy∶LaF_(3)晶体有望在可见光、中红外等激光领域得到应用。

Novel Dy^(3+)doped LaF_(3)crystals is synthesized by multi-crucible temperature gradient technology(MC-TGT).The crystallographic sites concentration is up to 5.90×1020 ions·cm-3 for 2%Dy∶LaF_(3)following the segregation coefficient of 0.8 measured by inductively coupled plasma emission spectrometer.The photoluminescence spectra of 1%Dy∶LaF_(3)show the strongest wavelength peaked at 601 nm and the widest wavelength band centering at 511 nm under excitation wavelength of 400 nm.By changing the excitation wavelength to 450 nm,the strongest wavelength shifts to 677 nm and the widest wavelength band shifts to 568 nm in 1%Dy∶LaF_(3),respectively.In the case of 2%Dy∶LaF_(3),two main central wavelengths at 478 nm and 571 nm are observed under excitation wavelength of 400 nm or 450 nm.The optical quality of as-grown Dy^(3+)∶LaF_(3)crystal is characterized by transmission spectra at the range of 2.5-11μm.The optical transmission of Dy∶LaF_(3)crystal with thickness of 0.96 mm reaches over 85%,indicating a high-optical quality in the range of 2.5-9μm.Thus,Dy∶LaF_(3)has great application potentials in visible and mid-infrared laser.