本文利用有籽晶的HPVGF法生长了尺寸为54 mm×25 mm的高质量CdSe单晶, 晶体为纤锌矿结构, (002)和(110)面的XRD摇摆曲线半高宽分别为54.4″和45.6″。使用红外显微镜和扫描电镜-能谱分析仪对晶体内部的夹杂相进行测试, 表明晶体内部存在小尺寸富Se夹杂相。CdSe晶片在2.5~20 μm范围内的透过率高于68%, 平均吸收系数为0.037 cm-1。制备出尺寸为10 mm×12 mm×50 mm且满足第Ⅱ类相位匹配条件的CdSe晶柱, 在重频1 kHz, 波长2.09 μm的Ho∶YAG调Q泵浦源激励下, 实现了中心波长为11.47 μm, 线宽为33.2 nm的激光输出, 最大输出功率为389 mW。

High quality CdSe single crystal, with the sizes of 54 mm in diameter and 25 mm in length, was successfully grown by a high pressure vertical gradient freeze (HPVGF) technique using seed. The full width at half maximum (FWHM) of (002) and (110) X-ray rocking curves of the CdSe crystal with wurtzite structure are 54.4 arcsec and 45.6 arcsec respectively. The results show that there are some small-size Se inclusions in CdSe crystal by the test of infrared microscope and SEM-EDS. The transmission spectra show that the infrared transmission is above 68% and the mean absorption coefficient is 0.037 cm-1 in the range of 2.5-20 μm. Using fabricated type II CdSe crystal with the dimensions of 10 mm×12 mm×50 mm, we demonstrated an optical parametric oscillator (OPO) pumped by a 2.09 μm acoustooptic Q-switched Ho∶YAG laser at a pulse repetition frequency of 1 kHz. Up to 389 mW output is obtained at the idler wavelength of 11.47 μm with a linewidth of 33.2 nm.