In the laser deposition of single crystal and directionally-solidified superalloys, it is desired to form laser deposits with high volume fractions of columnar grains by suppressing the columnar-to-equiaxed transition efficiently. In this paper, the influence of beam profile (circular and square shapes) and cooling conditions (natural cooling and forced cooling) on the geometric morphology and ...

Polycrystalline silicon (poly-Si) thin film transistors (TFTs) fabricated by near-infrared femtosecond laser annealing (FLA) are demonstrated. The FLA-annealed poly-Si channels exhibit low tail-state, deep-state, and midgap-state densities of grain traps. Characteristics such as field-effect mobility, threshold voltage, and subthreshold slope for FLA-annealed poly-TFTs are comparable to those o...

Magnetic properties of Co-C nanodot arrays produced by direct interferometric laser annealing are investigated by magnetic force microscopy (MFM) and magnetization measurements. The dots are formed by locally annealing sputtered amorphous Co-C films in regions where the laser intensity is highest. As-sputtered Co-C films do not exhibit ferromagnetic order at room temperature, but MFM shows that...

Applications based on the propagation of high power laser radiation through the atmosphere are limited in range and effect, due to weather dependent beam wandering, beam deterioration, and scattering processes. Security and defense related application examples are countermeasures against hostile projectiles and the powering of satellites and aircrafts. For an examination of the correlations bet...

We propose an original route to prepare magnetic alloy nanoparticles with uniform size and shape by using nanosecond annealing under pulsed laser irradiation. As demonstrated here on CoPt nanoparticles, flash laser annealing gives an unprecedented opportunity to control the size and the shape of bimetallic nanoparticles without changing their composition. The mechanisms involved in the complete...

Articles you may be interested in A model of electrical conduction across the grain boundaries in polycrystalline-silicon thin film transistors and metal oxide semiconductor field effect transistors Polycrystalline silicon thin-film transistors with location-controlled crystal grains fabricated by excimer laser crystallization Appl. Improvement of the electrical performance in metal-induced lat...

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 ...

In this paper, we present our studies on thermally assisted recovery of low energy electron beam induced optical degradation of gallium nitride. A clear reduction in MOVPE grown GaN band-to-band photoluminescence intensity induced by low energy electron beam irradiation has been found before. Partial recovery of the band-toband emission was observed after annealing in both H2 and N2 ambient, at...

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...