Yb∶YAG激光晶体的高温退火和高浓度掺杂效应

Influence of Annealing and Doping on Yb∶YAG

测定了提拉法生长的不同掺杂浓度的Yb∶YAG晶体从紫外到近红外区的吸收光谱 ,发现高温氧化气氛退火后原先可见光区色心宽带吸收消失的同时 ,在紫外区出现新的吸收带 ,并通过色心的转化对这一现象进行了解释。在紫外区和近红外区吸收光谱中 ,发现随掺杂浓度的升高 2 2 0nm和 94 0nm附近的吸收带的位置略有移动 ,提出是由于Yb3+ 离子掺杂引起的晶格结构畸变导致了Yb∶YAG晶体光谱性质的改变。通过X射线衍射对不同掺杂浓度Yb∶YAG晶体晶胞参数的测定 ,证实高的掺杂浓度导致Yb∶YAG晶体发生较大的晶格畸变。在不同掺杂浓度Yb∶YAG晶体的激光实验中 ,观察到Yb3+

The UV, visible and IR absorption spectra of annealed and as grown Yb∶YAG grown by Czochralski technique were measured, and some changes of absorption bands and shifts of absorption peaks are observed and discussed. With the disappearance of broad absorption bands of color center at 370 nm and 625 nm, the new absorption band at 254 nm of annealed Yb∶YAG is probably the result of change of color center. The little shifts of absorption peaks at 220 nm and 940 nm are regarded as the result of crystal lattice deformation, which was proved by X ray diffraction. In laser experiment of Yb∶YAG crystals, the influence of doping level on laser performance has been observed