RESUMO
The factor group symmetry analysis method was used to analyse the Raman spectra of neodymium-doped yttrium orthoanadate Nd:YVO4 which were measured at room temperature with different geometrical configurations. All the Raman peaks were assigned on the basis of the group theory and lattice dynamics thoery. According to the peak numbers of the Raman spectra, we concluded that the primitive cell of Nd:YVO4 contains four formula units.
Assuntos
Oxigênio/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise Espectral Raman/métodos , Itérbio/química , Ítrio/química , Neodímio/química , Oxirredução , TemperaturaRESUMO
The principal refractive indices of a Nd0.007Gd0.993VO4 crystal for wavelengths of 0.488, 0.6328, 1.064, 1.0795, and 1.3414 microm under the temperature range of 20-170 degrees C are measured by the autocollimation method, and the Sellmeier's equation and the expression of the thermal refractive-index coefficient are then obtained. The reliability of these results is checked by comparing the calculated values with the measured values for the measured wavelengths and the temperature region, as well as with the published values by Studenikin et al. [Quantum Electron. 25, 1162-1165 (1995)] for wavelengths of 0.491, 0.546, 0.578, 0.632, 0.808, and 1.062 microm at 20 degrees C. In addition, the birefringence and the thermal coefficient of the birefringence were obtained by measured results. The results show that the birefringence is larger than that of a YVO4 crystal and that the thermal coefficient of birefringence is less than that of a YVO4 crystal. Therefore it can be expected that the GdVO4 crystal is not only an excellent laser crystal but also an excellent birefringent crystal used in a modern optical transmission system as a passive fiber-optic component.