RESUMEN
We report a diode-pumped passively Q-switched Nd:LuVO4 laserat 1.34 microm using V3+:YAG as saturable absorber. The characteristics of a-cut and c-cut Nd:LuVO4 passive Q-switching operation were studied. The average output power of 1.02 W was obtained under the pump power of 12.88 W, corresponding to the optical conversion efficiency of 8% and slope efficiency of 10% in c-cut Nd:LuVO4 laser. The maximum pulse energy of 17.6 microJ and the highest peak power of 820 W were obtained at pulse width of 21 ns and pulse repetition rate of 22.4 kHz in a-cut Nd:LuVO4 laser.
Asunto(s)
Láseres de Estado Sólido , Neodimio/química , Diseño de Equipo , Análisis de Falla de EquipoRESUMEN
Based on the space group theory, the normal vibration modes of DKDP crystal were analyzed and the assigned. Raman spectra were measured at the room temperature. Results show that the lattice vibration spectra of DKDP arise mainly from the internal vibrations of D2PO4(-) anionic cluster. Compared with the Raman spectra of an aqueous solution of KH2PO4 and an NaD2(PO4)2 crystal, the four internal vibration models of the D2PO4(-) in DKDP were assigned as 881 cm(-1) (v1), 357 cm(-1) (v2), 514/541 cm(-1) (v3), 965 cm(-1) (v4), respectively.
RESUMEN
The CNGS crystal belongs to the trigonal system, the 32 point group and the P321 space group, which is the same as the LGS crystal. Its lattice constants are a = 0.808 73 nm and c = 0.497 98 nm. The primitive cell of the CNGS crystal contains only one formula unit (23 atoms). The vibration modes were measured with Raman spectroscopy technique, assigned with ab initio molecular orbit calculation method. In order to model the crystal, two clusters Ca3NbGa2SiO12 and Ca3NbGaSi2O12 were designed, and calculations were carried out on them. Their configurations were optimized, and the vibration frequencies were calculated with UHF method. By investigating the force constants and activities of the assigned Raman spectra, the structure of CNGS crystal was analyzed, and its layer structure and piezoelectric properties were confirmed. It is concluded that CNGS crystals have more excellent anisotropy and piezoelectric properties than LGS crystals.
RESUMEN
The factor group symmetry analysis method was used to predict lattice vibrational modes of MMTWD single crystal, and it was found that there are no more than 297 and 148 theoretically observable Raman peaks and infrared reflection bands, respectively. The Raman and IR spectra were measured at room temperature. All the Raman and IR spectra peaks were assigned on the basis of the group theory and lattice dynamics theory. According to the Raman and IR spectra, the molecular structure of MMTWD crystal was discussed. From the results of the present theoretical and experimental works, the three-dimensional network structure of MMTWD crystal was identified. This structure provides the crystal with a large interaction force between molecules, which in turn induces high stability and macroscopic nonlinear optical properties.
RESUMEN
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.