Midinfrared lasers with an asymmetrical InPAsSb/InAsSb/AlAsSb double heterostructure are reported. Using the asymmetrical double heterostructure, pand n-cladding layers are separately optimized; high energy-gap AlAsSb (Eg'1.5 eV! for the p-type cladding layer to reduce the leakage current, and thus to increase To , and low energy-gap InPAsSb (Eg'0.5 eV! for the n-cladding layer to have low turn...

Explosion metal welding is high-speed angle oblique collision of two or more metal plates caused by detonation. The metal is joined – welded under high dynamic pressure creating by plastic deformation the waves on the bond interface, accompanied by local adiabatic heating 1 . The explosive metal cladding process can be divided into three stages: a) generation of explosion energy through the det...

We present analytical results that shed new light on the properties of photonic-crystal fibers (optical fibers with periodic structures in their cladding). First, we discuss a general theorem, applicable to any periodic cladding structure, that gives rigorous conditions for the existence of cutoff-free guided modes—it lets you look at a structure, in most cases without calculation, and by inspe...

The laser cladding of AA7075 powder onto a AA7075 substrate was conducted to evaluate the effect of heat treatment and measure residual stress between the clad layer and substrate in order to better understand the effect of laser cladding. The microstructure formed in the clad region was characteristic of a high cooling rate, which is typical for laser cladding. The heat affected zone showed co...

Reliable and efficient power generation is a major global issue due to both political and environmental concerns. Nevertheless many critical components, particularly the blades of the low pressure (LP) side of power generating steam turbines, are subjected to failure due to severe erosion at the leading edges. Since taking machines off-line for maintenance and removal of damaged blade for repai...

Semi-static dissolution tests using pressurized water reactor spent fuel rod segments and NNWSI reference J-13 well water 1n sealed stainless steel vessels at 85*C are being conducted In support of the Waste Package Task of the NNWSI Project. Test specimens include: bare fuel plus the empty cladding hulls, fuel rod segments with artificially induced cladding defects and water-tight end caps, an...

Protection of public and military personnel from chemical and biological warfareagents is an urgent and growing national security need. Along with this idea, we havedeveloped a novel class of fiber optic chemical sensors, for detection of toxic and biologicalmaterials. The design of these fiber optic sensors is based on a cladding modificationapproach. The original passive cladding of the fiber...

In this work we report two designs of subwavelength fibers packaged for practical terahertz wave guiding. We describe fabrication, modeling and characterization of microstructured polymer fibers featuring a subwavelength-size core suspended in the middle of a large porous outer cladding. This design allows convenient handling of the subwavelength fibers without distorting their modal profile. A...

-Electromagnetic wave propagation inside one-dimensional photonic crystal fiber is numerically characterized by computing V-parameter, cladding index and effective mode profiles. Dependence on these parameters on geometrical structure of the fiber reflects the design tolerance, and corresponding modal characteristics. Air-hole spacing and periodicity are varied to observe the effect on V-parame...