Why thermal laser epitaxy aluminum sources yield reproducible fluxes in oxidizing environments

Time-Division-Multiplexed Laser Sources for Measurements in Harsh Environments

High-repetition-rate hyperspectral absorption spectroscopy of water vapor has been used to measure gas properties in multiple combustion test articles at the Air Force Research Laboratory. A hyperspectral source is a source that sweeps or cycles through many spectral resolution elements. Although traditional semiconductor sources, most notably vertical-cavity surface-emitting lasers (VCSELs), c...

Pulsed Laser Deposition and Epitaxy

Laser is a powerful tool in many applications. It is especially useful in material processing. Thanks to it's narrow frequency bandwidth, coherence and high power density this instrument is used in many scientific research works and experiments. Often the light beam is intense enough to vaporize the hardest and most heat resistant materials. Besides, due to its high precision, reliability and s...

Why is random close packing reproducible?

We link the thermodynamics of colloidal suspensions to the statistics of regular and random packings. Random close packing has defied a rigorous definition yet, in three dimensions, there is near universal agreement on the volume fraction at which it occurs. We conjecture that the common value of phi{rcp} approximately 0.64 arises from a divergence in the rate at which accessible states disappe...

Aluminum Nitride Substrate Growth by Halide Vapor Transport Epitaxy

High-quality AlN layers with thickness up to 50 mm have been grown by HVTE at growth rates up to 60mm/h at deposition temperatures of 1000–11001C in the pressure range of 50–760Torr. The HVT process uses an aluminum chloride amine adduct as the aluminum source and ammonia for the nitrogen. This new technique eliminates the main difficulties of the conventional HVPE growth, where aluminum oxidat...

Yttrium Aluminum Garnet Laser Materials