Abstract: An alloy semiconductor can be grown using a container including a lower section containing a composition-control source material and an upper section containing a solid. The composition-control source material is heated to produce a vapor, and the solid charge is melted to form a melt with a melt meniscus extending to an inner surface of the container. The vaporized composition-control source material flows from the lower section to the upper and contacts the melt meniscus. The melt is then cooled to form a crystal.

Abstract: The laser has three regions p-n-n+ or n-p-p+ of magnetic element alloyed Group II-VI elements such as Cd, Hg, and Te doped with an element having a high atomic radius such as Sb or In. The magnetic element may be Mn or Fe. Vapor phase epitaxy is used to create a substrate having graded energy band gap characteristic across its thickness. A two-step liquid phase epitaxy process is used to grow an active layer and a passive layer to create the laser heterostructure. The index of refraction of the active region is higher than the indexes of refraction of the substrate and passive regions. The graded energy band gap and high doping of the substrate region results in a very low resistance which minimizes a temperature rise resulting from joule heating at high current densities. The relationship of the indexes of refraction of the layers result in double sided optical confinement to support lasing. In a semimagnetic semiconductor such as HgMnTe, the coefficient dE.sub.