中文摘要：

采用高温固相法合成了Cd3Al2Ge3O12：Cr3＋多晶材料,利用X射线衍射对其结构进行了分析,通过Cr3＋的室温吸收光谱、室温和77 K发射光谱分别对其光谱特性和晶场参数进行了分析和计算.结果表明：在450 nm的蓝光激发下,Cd3Al2Ge3O12：Cr3＋室温发射光谱主要由三个宽带及附加其上的弱R线构成,分别对应于Cr3＋的4T1,2T2,4T2到4A2能级跃迁.低温时宽带发射变弱,而R线变得强而锐.Cr3＋在Cd3Al2Ge3O12中晶场强度Dq/B为2.32,Stokes位移ΔES为1919cm-1,黄昆-里斯因子S为5.58.表明在Cd3Al2Ge3O12中Cr3＋处于弱的中等晶场强度,电子-声子耦合较强.4T2零声子能级与2E能级的间距ΔE仅为325.5cm-1,对Cr3＋可调谐激光的输出非常有利.

英文摘要：

Polycrystalline Cd3Al2Ge3O12：Cr3＋ was synthesized by high temperature solid-state method.Its crystal structure was analyzed by X-ray diffraction.Based on its absorption spectrum at room temperature and the emission spectra at room temperature and 77K,the spectral properties were investigated and the crystal field parameter was calculated.The results show that under the excitation of 450nm light,the emission spectrum of Cd3Al2Ge3O12：Cr3＋ at room temperature mainly consists of three broad bands with a weak R line.The three broad bands correspond to 4T1→4A2,2T2→4T2,and 4T2→4A2 transitions of Cr3＋,respectively.The broad band emissions weaken and the R line becomes stronger and sharper at low temperature.The calculated results showed the crystal field strength Dq/B=2.32,Stokes displacement ΔES=1919？cm-1 and Huang-Rhys factor S=5.58,which indicates that Cr3＋ in Cd3Al2Ge3O12 garnet are located in a weak crystal field strength and the coupling between the electrons and the phonons is strong,The distance ΔE between 4T2 zero phonon energy level and 2E energy level is only 326.5？cm-1,which is beneficial to the output of Cr3＋ tunable laser.