CHARACTERIZATION OF VISIBLE,TUNABLE SOLID STATE LASER MATERIALS

晶体中的过渡金属离子Cr^3+、Ti^3+和稀土离子Ce^3+被用作激光激活离子。由于它们的基态和激发态电子的电子-声子耦合是完全不同的，光学跃迁具有宽的吸收和发射带，从而产生宽的激光振荡调谐范围。最近报道了Cr^<3+>：LiCaAlF_6、Ti^<3+>：Al_2O_3和Ce^<3+>：LiYF_4晶体在室温下获得的光泵固体可调谐激光器。为了获得新的可调谐固体激光材料，我们研究了Cr^<3+>，Ti^<3+>，Ce^<3+>：用电子自旋共振（ESR）和光学光谱研究了CaYAlO_4（CYA）中Cr^<3 +>离子的电子自旋共振（ESR）谱，结果表明，Cr^<3+>离子在CYA中的第二近邻Ca^<2+>/Y^<3+>位置上具有有序和无序构型离子，分别。Cy <9->A中Ce^&lt;3+&gt;的g张量为g_<11>=2.6，g_*=1.6。ESR结果表明，Ce^&lt;3+&gt;在CYA中的基态波函数主要由|J，J_Z&gt;=| 5/2，5/2&gt;。Ce^（3+）在CYA中的吸收在200- 370 nm范围内，发光峰位于490 nm。

Transition metal ions Cr^<3+>, Ti^<3+> and rare earth ions Ce^<3+> in crystals are used as laser active ions. Since electron-phonon couplings of their ground and excited state electrons are quite different, the optical transitions feature broad absorption and emission bands, giving rise to a wide tuning range of laser oscillation. Recently, the demonstrations of optically pumped solid-state tunable lasers obtained from Cr^<3+> : LiCaAlF_6, Ti^<3+> : Al_2O_3, and Ce^<3+> : LiYF_4 crystals at room temperature were reported. In order to obtain new tunable solid state laser materials, we have examined the electronic properties of Cr^<3+>, Ti^<3+>, Ce^<3+> : CaYAlO_4 (CYA) using electron spin resonance (ESR) and optical spectroscopy.ESR studies of Cr^<3+> in CYA show Cr^<3+> ions in sites with ordered and disordered configurations of the second nearest-neighbor Ca^<2+>/Y^<3+> ions, respectively. The polarized intensities of the ^4A_2-^4T_2 absorption band and the R_1-line fluorescence suggest that the CrO_6^<9-> octahedra undergo an angular distortion such that the magnetic z-axis of the spectrum is rotated away from the crystal c-axis.The g tensor of Ce^<3+> in CYA was obtained to be g_<11>=2.6, g_*=1.6. The ESR results indicate that the wavefunction of the ground state of Ce^<3+> in CYA has a dominant component of |J,J_Z>=|5/2,5/2>. The absorption of Ce^<3+> in CYA was observed in the UV region (200-370nm) and the luminescence band has a peak at 490nm.