Kan Zhu

Effect of photonic bandgap on upconversion emission in YbPO 4 :Er inverse opal photonic crystals

We obtained upconversion (UC) light-emitting photonic materials (YbPO(4):Er) with an inverse opal structure by the self-assembly technique in combination with a solgel method. The effect of the photonic stopband on the UC luminescence of the (2)H(11/2), (4)S(3/2)→(4)I(15/2), and (4)F(9/2)→(4)I(15/2) transitions of Er(3+) has been observed in the inverse opals of the Er(3+)-doped YbPO(4). Significant suppression of the UC emission was detected if the photonic bandgap overlapped with the Er(3+) ions emission band, while enhancement of the UC emission occurs if the emission band appears at the edge of the bandgap.

Blue and green upconversion luminescence modification of Tb3+–Yb3+ co-doped Ca5(PO4)3F inverse opal

Tb3+–Yb3+ co-doped Ca5(PO4)3F inverse opal photonic crystals were prepared by a self-assembly technique in combination with a sol–gel method. Upconversion luminescence characteristics of the inverse opals were investigated. The results indicate that photonic band gap has a significant effect on upconversion luminescence of Tb3+–Yb3+ co-doped Ca5(PO4)3F inverse opal. Significant inhibition of the green or blue upconversion luminescence was inspected if the photonic band gap overlapped with the emission band of Tb3+ ions.

Effect of Optical Basicity on Broadband Infrared Fluorescence in Thulium-Doped Germanate Glasses

Influence of optical basicity on emission spectra at 1.45 μm of Tm3+ ions is investigated in alkali germanate glasses. The result shows that the bandwidth and intensity of emission spectra at 1.45 μm of Tm3+ depend on the optical basicity of the host glasses regardless of the glass systems. With the increasing in optical basicity, the 1.45 μm emission intensity decreased. It was found that the optical basicity calculated from glass composition may work as a guiding principle to obtain broadband fiber amplifier for wavelength division multiplexing systems.

Preparation and Upconversion Luminescence Properties of Tb3+-Yb3+ Co-Doped Phosphate Inverse Opals

Upconversion (UC) luminescence photonic band gap materials Tb3+-Yb3+ co-doped phosphate inverse opal photonic crystals were prepared by a self-assembly technique in combination with a sol-gel method. The effect of photonic band gap on UC luminescence was investigated in inverse opals. Effective suppression of the UC luminescence was inspected if the photonic band gap overlapped with the emission band of Tb3+ ions.