KTiOPO_(4)晶体中Cr离子的光谱特性

Spectral Properties of Chromium Ions in KTiOPO_(4) Crystal

通过实验测得ＫＴｉＯＰＯ４：Ｃｒ晶体的室温吸收谱、激发谱，室温和液氮温度下激光诱导荧光谱及各发射带的荧光寿命，进而计算得到了Ｃｒ离子的晶场参数、吸收截面、发射截面及量子效率。结果表明Ｃｒ离子受晶场的影响较弱，但具有较强的电子－声子耦合。室温下较大的无辐射跃迁几率导致了较低的量子效率。实验上没有观察到四配位Ｃｒ离子的光谱特征。最后，对上述结果结合Ｃｒ离子配位情况进行了讨论。

The absorption spectra and excitation spectra at room temperature,the laserinduced fluorescence spectra and the fluorescence lifetime both at room temperature and liquid-nitrogen temperature of a Cr:KTP crystal are measured experimentally.On the basis of the results the ligand parameters,absorption cross-setion,emission cross-setion and quantum efficiency(QE) of the active chromium ions are calculated.It is found that the chromium ions are in the weak ligand, but show strong electron-phonon coupling.The lower QE at room temperature is assigned to a strong nonradiative relaxtion.No spectral character of the chromium ions Of tetrahedron is observed.