水平梯度冷凝法生长优质ZnGeP_2单晶与性能表征

Growth of Pure ZnGeP_2 Crystals by Horizontal Gradient Freeze Method and Its Properties

用自制的双温区机械震荡管式炉合成了Zn Ge P2多晶,单次合成量超过500 g。采用水平梯度冷凝法生长了质量为350~395 g的Zn Ge P2单晶,单晶最大尺寸为25 mm×32 mm×165 mm。通过X射线粉末衍射、摇摆曲线以及红外透射光谱等研究了合成的多晶和生长的单晶品质。结果表明:晶体(100)面摇摆曲线半峰宽为33″~42″,且峰型锐利、对称;在3~8μm的吸收系数小于0.01 cm^(–1),2μm处吸收系数小于0.03 cm^(–1)。另外,制备了Zn Ge P2光学参量震荡器件,该器件在2μm激光泵浦下成功输出3~5μm可调谐激光,光光转化效率为56.2%。表明生长的Zn Ge P2晶体具有较高的品质,能满足应用要求。

More than 500 g of high-pure ZnGeP2 polycrystalline was synthesized in a homemade two-temperature zone mechanical oscillation furnace. The ZnGeP2 （ZGP） crystals with the mass of 350–395 g and the dimensions of 25 mm×32 mm×165 mm were grown by a horizontal gradient freeze method. The quality of polycrystalline and single crystal of ZGP was investigated by powder X-ray diffraction, rocking curve, and Fourier infrared transform spectroscopy, respectively. The results show that the full width at half maximum （FWHM） of the （100） peak rocking curves are between 33″ and 42″, and the absorption coefficient of the ZGP crystal is lower than 0.01 cm^–1 in the wide range of 3–8 μm and lower than 0.03 cm^–1 at 2 μm. Moreover, the ZGP–OPO （optical parametric oscillation） devices were prepared with ZGP crystal. The ZGP–OPO device implements 3–5 μm tunable laser output pumped by 2 μm laser with the photon conversion efficiency of 56.2%. It is indicated that the ZGP crystals grown have a high optical quality for the applications.