泡生法生长KYb(WO4)2晶体及其结构与光谱性能

对顶部籽晶提拉法(TSSG)进行了改进,采用泡生法生长KYb(WO4)2晶体(简称KYbW),以0.05℃/h的速率降温生长,转速5~10 r/min,生长周期10~15 d,降温速率15~20℃/h。研究了KYbW晶体的结构,给出了两种晶胞的选取方法。通过晶体的X射线衍射(XRD)谱,计算出晶体的两种晶格常数分别为a=1.061 nm,b=1.029 nm,c=0.749 nm,β=130.65°;a′=0.807 nm,b′=1.029 nm,c′=0.749 nm,β′=94.34°。测得晶体的吸收光谱,结果表明其吸收带在920~1000 nm,计算出主吸收峰981 nm处的吸收截面为11.12×10-20cm2。测得晶体的荧光光谱,结果表明KYbW晶体在1007 nm和1037 nm附近都有较强的发射峰,主峰1037 nm处的发射线宽(FWHM)达13 nm,因此KYbW晶体可作为可调谐激光增益介质,计算出1037 nm处的受激发射截面积eσm=3.4×10-20cm2。

Structure and Spectra Characteristics of KYb(WO4)2 Crystal Grown by Kyropoulos Method

In this paper, KYb(WO4)2 (KYbW) crystal has been grown by Kyropoulos method, and the craft parameters were obtained, cooling growth at 0.05 ℃/h, rotational speed was 10 r/min, growth period was 10～15 d, and lower the temperature at 15～20 ℃/h. The crystal structure was studied, and two ideas for accessing unit cell were presented. The lattice parameters of KYbW were, a=1.061 nm, b=1.029 nm, c=0.749 nm, β=130.65° and a′=0.807 nm, b′=1.029 nm,c′=0.749 nm,β′=94.34° calculated by X-ray diffraction (XRD) analysis. The absorption spectrum and fluorescence spectrum of KYbW were measured. The absorption cross section at 981 nm was calculated to be 11.12×10-20 cm2. The emission wavelength of fluorescence was 1007 nm and 1037 nm, and the emission line-width at the chief peak 1037 nm run up to 13 nm, so KYbW was an excellent gain medium for tunable laser. The emission cross section at 1037 nm was calculated as 3.4×10-20 cm2.