【摘要】 Cr³⁺掺杂在GeO₂单晶中,其温度为10K—290K时都可观察到Cr³⁺的双光子吸收。同时吸收双光子后,Cr³⁺离子被激发到⁴T₁（p）态,经无辐射跃迁到²T₁₈。和²E_g态,最后辐射出一个光子回到基态⁴A₂（F）,其辐射光的偏振特性与泵浦光完全一致。按配位场理论计算的配位场参数分别为Dq=1620cm^-1,B=577cm^-1,C=3122cm^-1。所观察到的激发谱线和辐射谱线的微细分裂被归结为⁴A₂（F）的分裂。从明显的各向异性结果看,Cr³⁺是处在具有低对称畸变的八面体对称的晶格位置。更多还原

【Abstract】 Two-photon absorption of Cr3+ ions in GeO2 in the temperature interval of 15K-290K was reported. Having absorbed two photons simultaneously, the Cr3+ ion is excited to 4T1(P) from its ground state4A2(F), then via radiation-less transitions, it decays to 2Tig and 2Eg states. At last it emits one photon and decays to 4A2(F) again. The polarization properties of emission light are in agreement with that of pump light. According to ligand field theory, estimated values of the parameters of ligand field are given, i.e. Dq=1620 cm-1, B=557 cm-1, C=3122 cm-1. The observed small splittings of emission and excitation lines are attributed to the splitting of 4A2(F). From the anisotropic results, Cr3+ ions occupy octrahedral lattice positions with low symmetry distortion.更多还原