温度梯度法生长大尺寸钛宝石晶体研究

Study on Growth of Large-sized Ti∶ Al_2O_3 Crystals by the Temperature Gradient Technique

采用温度梯度法生长了不同掺杂浓度的钛宝石(Ti∶Al2O3)激光晶体,经退火加工获得的最大晶体尺寸达到86 mm×37 mm。室温下利用紫外-可见-近红外分光光度计测试了晶体300~1000 nm波段的吸收,分析了该系列晶体的吸收特性。结合晶体径向527 nm的吸收测试分析了晶体径向掺杂均匀性,同时使用Zygo干涉仪测试了晶体的光学均匀性,结果表明所生长的大尺寸钛宝石晶体具有良好的掺杂及光学均匀性。通过化学腐蚀法,利用光学显微镜观察表征了晶体位错密度,为2.9×103/cm2。

Titanium-doped sapphire （Ti： Al2O3 ） crystals with different doping contents were grown by the temperature gradient technique, and the crystal with dimension of φ86 mm × 37 mm was obtained. The absorption features of these crystals were analyzed through the results of absorption spectra measured by a ultraviolet/visible/near infrared （UV/Vis/NIR） spectrophotometer at room temperature over the range of 300-1000 nm. The radial doping uniformity of large-sized Ti： Al2O3 crystal was evaluated according to the absorption fluctuation at 527 nm, and the optical homogeneity was also determined by a Zygo intefferometer. The dislocation density of Ti： Al2O3 crystal was characterized to be 2.9 × 103/cm^2 with an optical microscope after etching the polished c-cut sample.