Objectives: A water pipe (hookah) is a tobacco smoking tool which is thought to be more harmless than a cigarette, and there are no adequate studies about its hazards to health. Water-pipe smoking is threatening health of the youth in the world today. The objective of this study has been to investigate the carbon monoxide (CO) levels in breath, examine the changes in pulmonary function tests (P...

in the construction process of a plastic concrete cut-off wall, concreting is usually performed using the termie pipe method. in this method, concreting is performed from the lowest point in the excavated trench (containing the slurry) using a funnel and the pipe connected to it. the concrete poured in the funnel gradually settles in the panel through the termie pipe which is beneath the slurry...

We report on photochemical two-photon Bragg grating preparation in hydrogenated fiber without any UV-induced stress in the core or cladding, leaving only the color-center model responsible for refractive index changes for UV femtosecond irradiation. Without hydrogen loading strong stress changes are observed in the core and in the cladding indicating glass compaction. The irradiation does not c...

Thin glass fibers imbedded into a glass cladding of slightly lower refractive index represent a promising medium for optical communication. This article presents simple formulas and functions for the fiber parameters as a help for practical design work. It considers the propagation constant, mode delay, the cladding field depth, and the power distribution in the fiber cross section. Plots vs fr...

This work reports on the Q-switched pulsed laser generation from double-cladding Nd:YAG ceramic waveguides. Double-cladding waveguides with different combination of diameters were inscribed into a sample of Nd:YAG ceramic. With an additional semiconductor saturable absorber, stable pulsed laser emission at the wavelength of 1064 nm was achieved with pulses of 21 ns temporal duration and ~14 μJ ...

A simple, flexible method of postfabrication positioning of resonance wavelengths of long-period cladding-modecoupled gratings is proposed. This method is based on changing the outer fiber diameter. Reducing the diameter by etching the fiber in HF acid shifts the loss peaks to higher wavelengths. A shift as large as 130 nm after 5 min of HF etching was observed for our strongest grating peak, c...

The stress corrosion cracking behavior of an Incoloy825/X65 bimetallic composite pipe welded joint in wet hydrogen sulfide (H2S) environment was investigated by means the creviced bent beam (CBB) test this study. microstructure, element distribution and crack propagation were analyzed optical microscope (OM), scanning electron (SEM), dispersive spectroscopy (EDS) backscatter diffraction (EBSD)....

We investigate the performance of a simple corrugated aperture scanning near-field optical microscope (SNOM) probe with various cladding metals. The probes have only one corrugation, however, they offer increased transmission over both uncorrugated probes and those with many grooves. Enhancement of light throughput results from excitation of surface plasmons at the corrugation at the core-cladd...

We propose a holey fiber design to achieve single-polarization single-mode (SPSM) guidance. The photonic crystal fiber (PCF) has a triangular-lattice with elliptical airholes in the microstructured cladding and circular airholes in the core. The SPSM guidance can be obtained by designing the PCF structure such that the fundamental space-filling mode (FSM) of the core region is positioned betwee...

We demonstrate a novel all-fiber acousto-optic tunable notch filter based on coupling to cladding modes in a single-mode fiber. The device has the advantage of low loss (<0.1 dB) and low polarization dependence. By coupling input light to multiple cladding modes by use of multiple acoustic waves, we achieved an electronically controllable variable spectral profile without a significant coherent...