A novel high birefringence photonic crystal fiber (PCF) was proposed, which consists of hexagonal inner ring and
octagonal outer ring. A full vector finite element was applied to investigate the mode birefringence and chromatic
dispersion. It has been demonstrated from the calculated results that high birefringence to the order of 0.001 can be
achieved and ultra-flattened dispersion of -0.8~+0.2 ps/(km•nm) is obtained in 1.5 to 1.65μm wavelength range.
A series of Zn, Fe double-doped LiNbO<sub>3</sub> crystals were grown by Czochralski technique with 0.015wt% of Fe<sub>2</sub>O<sub>3</sub> and with different concentration of ZnO. The defect structures of the Zn:Fe:LiNbO<sub>3</sub> crystals were studied by X-ray diffraction analyses and IR absorption spectra. The results indicated that the lattice constants of the Zn:Fe:LiNbO<sub>3</sub> increase with the concentration of ZnO increasing in the crystals. The result indicates that the absorption peaks of the IR transmission spectra shift to the shorter wavelength with the increasing of concentration of ZnO. The optical damage resistance ability of the Zn:Fe:LiNbO<sub>3</sub> crystals were investigated by straightly observing transmission facula distortion method, respectively. The results demonstrate that, compared with of Fe:LiNbO<sub>3</sub>, the optical damage resistance ability of the Zn (7.0mol%):Fe:LiNbO<sub>3</sub> crystals is two orders magnitude higher than that of LiNbO<sub>3</sub> crystal. 6.0mol% of ZnO is the perfect doping concentration.
Nondoped and Ce<sub>2</sub>O<sub>3</sub> doped near stoichiometric LiNbO<sub>3</sub> (Ce:LiNbO<sub>3</sub>) single crystals were grown by the top-seeded solution method. The solution with [Li]/[Nb] ratio of 1 contained K<sub>2</sub>O component of 10.6 mol%(7.0 wt%). The ultraviolet-visible absoprtion spectra of the crystals were measured in order to analyze their structure. The photorefractive properties of stoichiometric LiNbO<sub>3</sub> crystals were investigated and compared with congruent LiNbO<sub>3</sub> crystal. Two-wave-coupling experiments shown that doped stoichiometric LiNbO<sub>3</sub> crystals exhibited much larger photorefractive gain and faster response speed than congruent ones.
The Tb:Fe:LiNbO<sub>3</sub> and LiNbO<sub>3</sub> crystals with vary Li/Nb ratio in the melt were grown by the top-seed solution growth (TSSG) method and Czochralski technique, respectively. Their Li/Nb ratios were calculated by the lattice parameters. The defect structure of the Tb:Fe:LiNbO<sub>3</sub> and LiNbO<sub>3</sub> with vary Li/Nb ratio in the melt crystals was studied by X-ray analyses and UV spectra. The results show that an increase of Li/Nb ratio in the melts leads to a decrease of the lattice constants, which is accompanied by an improvement of the LiNbO<sub>3</sub> lattice structure because of diminishing concentration of intrinsic nonstoichiometric defects.
The formation of PtSi ultra-thin film prepared by pulsed laser deposition during pulsed laser annealing has been studied. The growth sequence of the Pt<SUB>2</SUB>Si and the PtSi phases that evolved as the result of the diffusion reaction in the bilayers was monitored by X-ray photoelectron spectrum (XPS). The structure characteristics of PtSi thin films prepared by different preparing conditions were investigated by X-ray diffraction and XPS. Compared to conventional furnace anneal, we got superior uniformity, lower continuous film thickness of the resulting PtSi layers and smoother PtSi/Si interfaces.