Size-dependent photoluminescence characteristics from Ge nanocrystals embedded in different oxide matrices have been studied to demonstrate the light emission in the visible wavelength from quantum-confined charge carriers. On the other hand, the energy transfer mechanism between Er ions and Ge nanocrystals has been exploited to exhibit the emission in the optical fiber communication wavelength...

SiGe nanowires of different Ge atomic fractions up to 15% were grown and ex-situ n-type doped by diffusion from a solid source in contact with the sample. The phenomenon of dielectrophoresis was used to locate single nanowires between pairs of electrodes in order to carry out electrical measurements. The measured resistance of the as-grown nanowires is very high, but it decreases more than thre...

We report what is to our knowledge the first photochemical fabrication of a long-period grating in a pure-fused-silica photonic crystal fiber. The inscription technique is based on a two-photon absorption mechanism and does not require a specially designed photonic crystal fiber with a photosensitive Ge-doped core. The characteristic fluence value for the inscription is an order of magnitude le...

Using high-intensity femtosecond pulses at l5264 nm, we have measured the two-photon absorption ~TPA! coefficient in three fused silica samples Suprasil, Herasil, Infrasil ~Heraeus! and in 3.5 mol % Ge-doped fused silica. While in fused silica samples the TPA coefficient value is about 2310 cm/W, in germanosilicate glass it equals (4263)310 cm/W. © 2002 American Institute of Physics. @DOI: 10.1...

The relationship between paramagnetic defect centers and UV absorption bands simultaneously generated by ionizing radiation in Ge-doped SiO2 glass is investigated using magneto-optical techniques. A sample of 7.0 mol% Gedoped SiO2 was exposed to X-ray radiation, which resulted in the formation of absorption bands centered at 4.4 eV and 5.7 eV as well as electron spin resonance (ESR) signals att...

A full-vectorial finite-element-based approach has been developed to find accurate modal solutions of acoustic modes in Ge-doped planar silica waveguides. The structural symmetry is exploited, and Aitken's extrapolation is also used to improve the accuracy of the solution. The spatial dependences of the dominant and nondominant displacement vectors are shown for the fundamental and higher-order...

The Journal of Physical Chemistry C is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Article Hydrogen Spillover Enhanced Hydriding Kinetics of Palladium-Doped Lithium Nitride to Lithium Imide Chikai Lin, Tao Xu, Jiamei Yu, Qingfeng Ge, and Zhili Xiao J. Phys. Chem. C, 2009, 113 (19), 8513-8517• Publication Date (Web): 21 April 2009 Downloaded from ...

We present an experimental investigation regarding the changes induced by the Ge doping level on the emission profile of the germanium lone pair center (GLPC) in Ge doped silica. The investigated samples have been produced by the sol-gel method and by plasma-activated chemical vapor deposition and have doping levels up to 20% by weight. The recorded photoluminescence spectra show that the GLPC ...