Yaqin Yu

Concentration effects of Er3+ ion in YAG : Er laser crystals

Laser crystals of (Y1-xErx)(3)Al5O12, (YAG:Er) have been grown by the Czochralski method and the spectral properties have been studied for different Er3+ concentrations. The effects of various Er3+ concentrations on the structural distortions, luminescence quenching Of F-4(9/2), H-2(11/2), S-4(3/2) and red shift in laser wavelength have been discussed for the YAG:Er laser crystals. By using absorption spectra and Judd-Ofelt theory the experimental oscillator strengths, Omega(lambda), parameters and the excited state integrated absorption cross sections of Er3+ ion are reported and some variation regularities of these parameters have been observed

STRUCTURE AND SITE-SYMMETRY INVESTIGATION ON THE HEXAGONAL KCAY(PO4)(2)

A new double phosphate, KCaY(PO4)(2), isostructural with hexagonal LaPO4, is reported. It crystallizes in the hexagonal system with a = 0.6903 nm and c = 0.6331 nm. Its vibrational spectra, IR and Raman spectra showed that the site symmetry of the PO4 anion slightly deviated from D-2 toward C-2.

Spectral characteristics of Er3+-activated and Ce3+-sensitized yttrium aluminium garnet laser crystals

We report in this paper the spectral characteristics of Er3+ (2 at.%)-activated and Ce3+ (0.3 at.%)-sensitized yttrium aluminium garnet (YAG:Er,Ce) laser crystals grown by the Czochralski technique. The absorption and emission spectra were measured at room temperature. By using absorption spectra and Judd-Ofelt theory the experimental oscillator strengths of the Er3+ transitions in the YAG:Er,Ce crystals were calculated. The energy transfer between the Er3+ and Ce3+ ions is also discussed.

catena-Poly­[[heptakis­(di­methyl­form­amide-κO)­di-μ4-oxo-tetra-μ3-oxo-hexa­deca-μ2-oxo-tetra­oxo­lan­than­um(III)­octamolybdenum(IV)]-μ-sodium(I)]

The title compound, [NaLaMo(8)O(26)(C(3)H(7)NO)(7)](n), contains infinite chains of [Mo(8)O(26)](4-) units supporting dimethylformamide-coordinated La(III) cations and linked by Na(+) cations. The lanthanum center adopts a nine-coordinate geometry and the Na atom is sandwiched between two beta-[Mo(8)O(26)](4-) units.