Articles you may be interested in Temperature modulation molecularbeam epitaxy and its application to the growth of periodic index separate confinement heterostructure InGaAs quantumwell lasers Periodic index separate confinement heterostructure InGaAs/AlGaAs multiple quantum well laser grown by organometallic vapor phase epitaxy Appl. Very low threshold single quantum well gradedindex separate...

The first high energy laser system that became operational at GSI is the ”nanosecond high energy laser for heavy ion experiments” (nhelix). This system has recently been improved significantly. Due to major changes in the system layout, the quality in terms of temporal and spatial beam homogeneity was improved, while at the same time the output energy was raised up to 120 J. This could be achie...

Pulsed laser irradiation is employed over a wide spectrum of materials processing applications, including surface hardening, alloying, curing, synthesis of compound and semiconductor films. In semiconductor systems,* it is used to anneal ion-implantation surface damage, recrystallize amorphous and polycrystalline films, and enhance dopant diffusion. Recent studies2 have shown that one of the mo...

We describe a simple experiment that demonstrates one-dimensional laser cooling in a sealed vapor cell. A velocity selective optical pumping scheme was first used to define a collimated beam of atoms within the cell. A particular velocity group of atoms was labeled by optical pumping with one laser and detected by absorption with a second laser. Transverse cooling of this velocity group, which ...

We report on the world’s first experiment of a parallel profile scan of the hydrogen ion (H) beam using a laser wire system. The system was developed at the superconducting linac (SCL) of the Spallation Neutron Source (SNS) accelerator complex. The laser wire profile scanner is based on a photo-detachment process and therefore can be conducted on an operational H beam in a nonintrusive manner. ...

The study of target injection, detection, measurement of laser focal point, and laser beam steering have started under co-research in Japan. The smooth-bore gas gun is developed for accurate injection. The applications of divergent laser beam and Arago spot are described for accurate measurement of target position and laser focal point. Magnetic lens for target trajectory adjustment by centerin...

Si Nanowires (NWs) were studied by Raman microspectroscopy. The Raman spectrum of the NWs reveals important thermal effects, which broaden and shift the one phonon Raman bands. The low thermal conductivity of the NWs and the low thermal dissipation are responsible for the temperature enhancement in the NW under the excitation with the laser beam. We have modeled, using finite element methods, t...

We report a method for characterizing the focussing laser beam exiting the objective in a laser scanning microscope. This method provides the size of the optical focus, the divergence of the beam, the ellipticity and the astigmatism. We use a microscopic-scale knife edge in the form of a simple transmission electron microscopy grid attached to a glass microscope slide, and a light-collecting op...

As the turbine industries need to manufacture turbine blades made of martensitic stainless steel AISI 420 with high toughness and wear resistance, local laser hardening has become more and more important. In this research, surface of the samples was initially hardened by high-power pulsed laser beam; then, optimum parameters of hardening were calculated and wear resistance of surface hardened s...

background: laser-tissue interaction on low-level laser therapy (lllt) has widespread medical applications (e.g., improved wound healing). the tensile strength of radiated tissue by lllt is known to be increased mainly because of cross collagen bands developed after radiation. objective: in this work, we studied the instantaneous effect of radiation of polarized laser beam on the viscoelastic t...