新型长波红外非线性晶体PbIn6Te10的生长

Growth of the new long-wave infrared nonlinear crystal PbIn6Te10

新型长波红外非线性晶体PbIn6Te10具有透光波段宽(1.3~31μm)、非线性系数大(d11=51 pm/V),双折射适宜(~0.05)等优点,在14~25μm乃至25μm以上波段具有较大应用潜力。文中通过相图分析结合具体实验,筛选出较合适的组分配比,并采用高温单温区法合成多晶,布里奇曼法生长出尺寸φ11 mm×55 mm的单晶棒。对生长的PbIn6Te10晶体进行X射线衍射、摇摆曲线、透过率等测试,结果表明,晶体为三方结构,晶格常格为a=b=1.496 1 nm,c=1.825 7 nm,生长出的单晶结晶性较好,半高宽(FHWM)约0.253°,2.5~25μm波段晶体的平均透过率在50%以上,对应收系数处于0.3~0.6 cm-1之间。

The new far-IR nonlinear crystal material PbIn6Te10 has great application potential among 14-25 μm even more than 25 μm because of its special optical properties, including clear transparency(1.3-31 μm), large nonlinear coefficient(d11=51 pm/V) and suitable birefringence(~0.05). The phase diagram analysis combined with the experiment was used to select the appropriate group distribution ratio, the PbIn6Te10 polycrystal was synthesized by high temperature single-temperature zone method(STZM), and single crystal with size of φ11 mm×55 mm was grown by Bridgman Method. The as-grown crystals were characterized by X-ray diffraction,X-ray rocking curve, infrared transmittance et al. XRD analysis indicates that the crystal has a trigonal structure,the lattice constants of a, b and c are 1.496 1 nm and 1.825 7 nm, respectively. The as-grown crystal is crystallized well(FHWM=0.253°), the infrared transmission is above 50% in the spectral region of 2.5-25 μm, the coefficient is 0.3-0.6 cm-1.