可调谐激光晶体GSGG∶Cr^(3+)在低温下光谱压致移位的理论研究

Theoretical studies of pressure-induced shifts of low temperature spectra in tunable laser crystal GSGG∶Cr^(3+)

采用单组态坐标模型 ,应用由对角化d3 能量矩阵而获得的波函数 ,同时考虑了自旋 轨道相互作用和电 声子耦合 ,并定量计入了4 T2 与2 T1各电子态对R线的影响以及局域压缩率和整体压缩率之间的差异 ,从微观的角度 ,研究了GSGG∶Cr3 + 低温下光谱结构的特点以及压力导致的R1线和4 T2 宽带的移位。理论计算的结果与实验符合较好 ,R线的常压位置及其分裂、R1线的压致移位及其“反转”现象和4 T2

On the basis of the single configurational coordinate(SCC) model, using the wave functions obtained from diagonalizing the d 3 energy matrix at normal and various pressures, taking into account both the electron-phonon coupling and spin-orbit interaction of 2E, 2T 1 and 4T 2, and considering the effects of all electronical states of 4T 2 and 2T 1 on R line as well as the difference between the local compressibility around Cr 3+ and the bulk one of the host crystal, spectroscopic features and pressure-induced shifts of R 1 line and 4T 2 broadband of GSGG∶Cr 3+ at low temperature have been microscopically studied. The calculated results are in very good agreement with experimental data. R-line energy at ambient pressure and its splitting, pressure-induced shifts of R 1 line and 4T 2 broadband, as well as the anticrossing behavior of pressure-induced shifts of R 1 line, have been reasonably explained.