顶部籽晶法生长Li掺杂非线性光学晶体SrB_4O_7

Growth of Li Doped Nonlinear Optical Crystal SrB_4O_7 by Top Seed Crystal Method

通过顶部籽晶法获得了大块Li掺杂的Sr B4O7(Li∶SBO)单晶,晶体尺寸为80 mm×11 mm×40 mm。元素分析和X射线衍射结果证明锂离子成功掺入SBO晶格中,并使掺入后的SBO晶胞有所增大。深紫外和紫外透过光谱显示Li掺杂后的SBO晶体紫外截止边相对于SBO的120 nm红移到了140 nm左右,倍频结果显示Li∶SBO晶体可实现较强的1064 nm的倍频光输出。晶体的缺陷研究结果显示,Li∶SBO晶体生长时容易在c轴方向上形成线状包裹体,腐蚀后的晶体表面发现了两种不同形貌的位错蚀坑,对应于晶体内部不同的位错形态。

Big Li doped SrB_4O_7 （Li： SBO） single crystal with size up to 80 mm× 11 mm × 40 mm was grown by the top-seeded solution growth （TSSG） method. The results of elemental analysis and X-ray diffraction indicate that the Li ＋ have been doped into the crystal lattice successfully, which makes the lattice volume of SBO become a little larger. The transmittance of the as-grown crystal in the DUV-UV range indicates that the UV absorption edge of the crystal shifts to 140 nm compared to the 120 nm of pure SrB_4O_7 crystal. Second-harmonic generation （SHG） test show that Li： SBO could be phase- matchable for the 1064 nm laser. Some defects of the crystal were studied and it was found that wire-like inclusions were apt to form along c-axis. Two kinds of etching pits corresponding to the different dislocation configuration were also detected on the crystal.