Search results for "Microstructure"

Visible Light Generation and Its Influence to Supercontinuum in As2S3 Microstructured Fiber

2011

We demonstrate visible light generation in As 2 S 3 microstructured fiber for the first time. It limits the spectral range of supercontinuum. The visible light generation can be avoided by designing the fiber for the single-mode operation.

Microstructure alterations of rotary files after multiple simulated operative procedures.

2009

Aim: To assess morphological alterations of ProTaper rotary NiTi files before and after continuous use by scanning electron microscopy (SEM). Study Design: 30 root canals were chosen with an angle between 15 and 30º. Before starting to prepare the canals the files were observed microscopically using a scanning electronic microscope. The ProTaper sequence recommended by the manufacturer was used, with NaOCl as irrigant. The instruments were sterilised after every three canals were shaped. The instruments were observed with the same microscope after shaping each canal, until 30 root canals were shaped. The criteria used for checking the instruments were: blunt cutting edges, disruption of cut…

Manufacturing of All-Fiber Q-Switch lasers for supercontinuum generation

2016

This work exposes the fabrication process of an All-Fiber Q-Switch laser and its use as a pump source for the generation of supercontinuum (SCG) with tapered microstructured fiber devices (tapers).

Nonlinear effects above 2 µm in chalcogenide suspended core microstructured optical fibers: Modeling and experiments

2011

We present our latest results on the linear and nonlinear modeling, and on the fabrication of chalcogenide suspended core microstructured optical fibers for mid-infrared generation. We focus on an AsSe glass composition. We have used a thulium-doped fiber laser to pump our fibers around 2 µm. In order to enhance further the nonlinearities and to manage the chromatic dispersion for supercontinuum application, we have tapered some of our microstructured optical fibers.

Linearly polarized all-fiber laser using a short section of highly polarizing microstructured fiber

2007

A linearly polarized all-fiber erbium laser is presented in this work. The polarization selective element consists on a piece of a single-mode, polarizing microstructured fiber, which is placed within the laser cavity. The microstructured fiber shows a regular lattice of air-holes, in which four holes next to the core were enlarged. This fiber shows a polarization dependent loss of 16 dB/m around 1550 nm. The laser cavity presents different losses for each polarization and, as a consequence, a highly polarized emission is obtained. The polarization ratio of the emitted power was in excess of 20 dB.

Chromatic Dispersion Control in Mode-Locked Yb-Doped Fiber Lasers Based on a Microstructured Optical Fiber

2013

We present an experimental study on the use of solid core microstructured optical fibers (MOF) for managing the chromatic dispersion in an Yb-doped fiber laser passively mode-locked by a saturable absorber. The performance of the laser, in terms of pulse width and repetition rate, was investigated as a function of the net cavity dispersion.

Incomplete retention of radiation damage in zircon from Sri Lanka

2004

A suite of 18 zircon gemstones from placers in the Highland/Southwestern Complex, Sri Lanka, were subjected to a comprehensive study of their radiation damages and ages. The investigation included X-ray diffraction, Raman and PL spectroscopy, electron microprobe, PIXE and HRTEM analysis, as well as (U-Th)/He and SHRIMP U-Th-Pb age determinations. Zircon samples described in this study are virtually homogeneous. They cover the range from slightly metamict to nearly amorphous. Generally concordant U-Th-Pb ages averaging 555 ± 11 Ma were obtained. Late Ordovician zircon (U-Th)/He ages scattering around 443 ± 9 Ma correspond reasonably well with previously determined biotite Rb-Sr ages for rock…

UNEVEN DISTRIBUTION OF ORGANOCLAY IN HDPE/PA6 BLENDS - IMPACT OF MICROSTRUCTURE AND MECHANICAL BEHAVIOUR

2009

The Effect of Tomography Imaging Artefacts on Structural Analysis and Numerical Permeability Simulations

2011

Fluid flow phenomena in porous materials can be found in many important processes in nature and in society. In particular, fluid flow through a porous medium contribute to several technological problems, e.g. extraction of oil or gas from porous rocks, spreading of contaminants in fluid-saturated soils and certain separation processes, such as filtration (Torquato, 2001). In paper and wood industry single and multi phase fluid flow properties in porous media play important roles related to manufacturing process and product development. The general laws describing creeping fluid flows are well known. However, a detailed study of fluid flow in porous heterogeneous media is complicated. This i…

The Structural and Dielectric Properties of the Li0.005Na0.995NbO3Ceramics

2009

The sodium niobate-lithium niobate (Li x Na1 − x NbO3) compounds were synthesized using conventional solid-state processing. Phase analysis was performed by X-Ray diffraction, and microstructural morphology was assessed by scanning electron microscopy. The dielectric measurements were performed in heating and cooling processes without and under axial pressure up to 120 MPa. It has been stated, that the maximum of electric permittivity ϵ (T) becomes more diffused with the increase of axial pressure and the temperature of phase transition T0 decreases. The value of tanδ increases with the increase of axial pressure and its local maximum shifts towards lower temperatures.