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The research aimed to study the kinetics of 400 nm blue emission during ultraviolet insolation on germanoslicate optical fiber, hydrogenated, and non-hydrogenataed. The hydrogenation of the fibers was carried out at room temperature under 150 atm for 4 weeks. The focused frequency doubled Argon laser ultraviolet beams were directed to the core of the unsheathed fiber. The light beams emerging from the end of the fiber were directed towards a detector. Kinetics the creation of defects in the hydrogenated fiber followed the power law for low-fluency insolation. At high fluency, the formation of defects followed the principle of two photosensitization or serial steps. [ABSTRACT FROM AUTHOR]

The aim of the research was to examine the formation and destruction of the hydroxyl in optical fibers by comparing the ambient atmosphere, air, and nitrogen during thermal treatment from room temperature up to 1100 °C. It has been shown that during the heat treatment, molecular hydrogen dissolved in the fiber plays no role in the formation of OH while under UV irradiation the formation is dependent on the presence of dissolved hydrogen. The heat treatment preferentially leads to the formation of Si-OH, while during irradiation it assists the formation of both Ge-OH and Si-OH. [ABSTRACT FROM AUTHOR]

Abstract: We report on fabrication of Er3+-activated LaF3 nanocrystals in transparent glasses using an original technique, which combines both heat treatment, below glass crystallization temperature, and ultraviolet laser irradiation at 244nm. The main advantage of this method is to control the spatial localization of the nanoparticles in the glass sample, whereas annealing solely at the crystallization temperature leads to a fully crystallized glass sample. Thermal differential analysis was used to determine the crystallization temperature of the sample. The photoluminescence spectra behaviour of Er3+ ions, collected from the UV-irradiated and unirradiated regions, allowed us to follow and to distinguish the structural changes in the glass network under heat treatment and ultraviolet exposure. [Copyright &y& Elsevier]

A simple and highly sensitive approach for the detection of the anti-neoplastic drug gemcitabine is presented, based on a one-step electropolymerized molecularly imprinted microporous-metal-organic-framework. The sensitive layer was prepared by electropolymerization of the aniline moieties of p-aminothiophenol- gold nanoparticles on the surface of gold electrodes tethered with p-aminothiophenol, in the presence of gemcitabine as a template molecule. Experimental parameters that control the performance of the sensor were investigated and optimized. Under optimal conditions a calibration curve was obtained in the linear range from 3.8 fM to 38 nM with a limit of detection of 3 fM. The obtained imprinted sensor has the advantages of easy manufacture, high sensitivity and selectivity and good reproducibility. Furthermore the feasibility of the proposed technique has been investigated on spiked serum samples and infusion solution containing gemcitabine., (Copyright © 2015 Elsevier B.V. All rights reserved.)

One-, two- or three-dimensional arrays of closely spaced silver nanoparticles may lead to new optical properties, due to short or long range coupling between their resonant surface plasmons, so that the spatially controlled growth of silver nanoparticles provides an efficient way to tune their optical properties. Towards this way, we present here the periodic pattern of a glass surface with silver nanoparticles by continuous ultraviolet laser exposure. The formation of the 160 nm period pattern is well described by an interference-based model which agrees with the experimental conclusions, mainly obtained by various forms of microscopy. Statistical approach based on the autocorrelation function gives quantitative description about the quality of the order in the periodic structure and about the nanoparticles averaged diameter (80 nm). We also present the optical extinction spectrum of the Laser Induced Periodic Surface Structure (LIPSS)-containing area of the glass, which unusually shows several bands in the visible range. The period of 160 nm of the periodic structure is short enough to allow coupling between nanoparticles, which makes it a possible candidate for plasmon-based optical applications.