锶镉锗硒(SrCdGeSe4)晶体是近期被发现的一种性能优异的新型红外非线性光学材料。本研究采用自制的双温区管式炉成功合成出SrCdGeSe4多晶, 单次合成量达到300 g; 采用坩埚下降法首次生长出SrCdGeSe4单晶, 尺寸为27 mm×80 mm; 通过定向、切割和抛光等程序, 得到几个不同尺寸的定向SrCdGeSe4晶片, 选取一片8×8×2 mm3双面抛光(110)晶片测试了摇摆曲线、红外透过光谱和激光损伤阈值。结果显示: (220)摇摆曲线半峰宽为44.8″, 该晶体的短波透过截止边为596 nm, 且在1~14 μm波长范围内透过率超过68%; 另外, 晶体在Nd∶YAG脉冲激光, 脉宽5 ns, 重复频率1 Hz, 光斑直径0.15 mm测试条件下, 激光损伤阈值为530 MW/cm2。

Strontium cadmium germanium selenide (SrCdGeSe4) crystal is a new infrared nonlinear optical material with excellent performance which was discovered recently. In this study, polycrystalline SrCdGeSe4 was synthesized successfully by using a self-made two-zone tube furnace with the amount of 300 g in one run. SrCdGeSe4 single crystal with size of 27 mm×80 mm was grown by vertical Bridgman-Stockbarger method for the first time. Several oriented SrCdGeSe4 plates with different sizes were obtained after orienting, cutting, and polishing processes. Measurements of rocking curve, infrared transmission spectrum, and laser damage threshold were carried out on a polished (110) plate with 8×8×2 mm3 in size. The results show that the FWHM of the (220) peak rocking curve is 44.8″; the crystal has a short-wave cutoff of 596 nm, and has highly transparent within the wide range of 1-14 μm with the transmittance over 68%, and possesses a surface laser damage threshold of 530 MW/cm2 using a Nd∶YAG laser under conditions of 5 ns pulse width, 1 Hz frequency, and D=0.15 mm spot size.