Photoluminescence (PL) is investigated as a function of the excitation intensity and temperature for lattice-matched InGaAs/InAlAs quantum well (QW) structures with well thicknesses of 7 and 15 nm, respectively. At low temperature, interface fluctuations result in the 7-nm QW PL exhibiting a blueshift of 15 meV, a narrowing of the linewidth (full width at half maximum, FWHM) from 20.3 to 10 meV...

This paper presents an alternative to conventional gamma camera. The proposed system is based on the combination of a new detection material – CZT and a new acquisition geometry – 1D detector with slat collimator. The slat collimator offers a better compromise to the usual sensitivity-resolution tradeoff. Solid-state detection offers significantly improved energy resolution. The combination of ...

The calculation for the optics of the synchrotron radiation small and wide angle x-ray scattering beamline, currently under construction at SESAME is described. This beamline is based on a cylindrically bent germanium (111) single crystal with an asymmetric cut of 10.5 degrees , followed by a 1.2 m long rhodium coated plane mirror bent into a cylindrical form. The focusing properties of bent as...

Thick GaN films were deposited with growth rates as high as 250 mm/h by the direct reaction of ammonia and gallium vapor at 1240 °C. The characteristics of our films are comparable to those of typical thin films grown by metal organic chemical vapor deposition or molecular beam epitaxy. Grown under identical conditions, films on ~0001! sapphire and on ~0001! 6H–SiC were compared in terms of the...

The discharge quality and optimum pump parameters of a long-pulse high-pressure gas discharge excited KrCl laser are investigated. A three-electrode prepulse–mainpulse excitation circuit is employed as pump source. The discharge volume contains a gas mixture of HCl/Kr/Ne operated at a total pressure of up to 5 bar. For a plane–plane resonator, the divergence of both output laser beams is measur...

In astronomy light emission is characterized by a frequency ω0/2π, a redshift z (sometimes a blueshift), a FWHM (Full Width Half Maximum) and an EW (Equivalent Width). ω0 relates to the nature of the concerned atom or molecule, z allows to determine the speed and the distance of the body through the Hubble law, FWHM measures the wave spectral width, and EW defines a kind of SNR (Signal-to-Noise...

We report that the Hα emission line of RS Oph was strongly variable during our 2004 observations on a time scale of 1 month. The line consisted of both a double peaked central narrow component (FWHM∼220 km s) and a strongly variable broad one (FWHM>2000 km s). The base of the Hα line was very broad with FWZI≈4600 km s on all spectra from 1986 to 2004. The variability of the broad component exte...

The leading spectrographs used for exoplanets' sceince offer online data reduction softwares (DRS) that yield as an ancillary result the full-width at half-maximum (FWHM) of cross-correlation function (CCF) is to estimate radial velocity host star. FWHM also contains information on stellar projected rotational vsini We wanted establish a simple relationship derive directly from computed by HARP...

We report the direct experimental observation of photonic nanojets created by single latex microspheres illuminated by a plane wave at a wavelength of 520 nm. Measurements are performed with a fast scanning confocal microscope in detection mode, where the detection pinhole defines a diffraction-limited observation volume that is scanned in three dimensions over the microsphere vicinity. From th...

Thin films of ZnO have been deposited on glass and silicon substrates by the pulsed laser deposition technique employing a KrF laser ~l5248 nm!. The influence of the deposition parameters, such as substrate temperature, oxygen pressure, and laser fluence on the properties of the grown films, has been studied. All the films grown over a rather wide range of deposition conditions were found to be...