Abstract: The laser device has an Al.sub.x Ga.sub.1-x As (x.gtoreq.0.3) quantum well active region having a thickness of 200 angstroms or less. Al.sub.y Ga.sub.1-y As (y>x) carrier supplying layers sandwich the quantum well active region therebetween. An Al.sub.z Ga.sub.1-z As (z>y) cladding layer is disposed on each of the carrier supplying layers. Finally an Al.sub.w Ga.sub.1-w As (w>z) barrier layer is disposed between each of the carrier supplying layers and each of the cladding layers.

Abstract: A semiconductor laser array device comprising a substrate having a plurality of adjacent striped channels on its surface, and a plurality of laser operation areas each of which contains a cladding layer, an active layer and another cladding layer which have been successively formed on the surface of said substrate by molecular beam epitaxy or metal organic chemical vapor deposition in such a manner that the surface of each of these layers becomes parallel to the surface of said substrate.

Abstract: A semiconductor laser apparatus comprising: a semiconductor laser array device in which a plurality of laser operation areas are disposed in a parallel manner to attain optical phase coupling therebetween and laser lights are propagated with a 180.degree. phase shift therebetween in the adjacent laser operation areas, resulting in a far-field pattern having a peak in each of the two different directions of the emission of said laser beams therefrom, and a stem containing the semiconductor laser array device therein in such a manner that one of the the laser lights from the semiconductor laser array device is blocked with the inner wall of the stem and the other laser beam passes outside of the stem.

Abstract: An apparatus for the growth of semiconductor crystals in which the surface of a substrate is irradiated with molecular beam containing elements by which semiconductor thin films are formed on the substrate within a molecular beam epitaxial growth chamber in a high vacuum, thereby achieving molecular beam epitaxial growth of semiconductor thin films onto the substrate, wherein said molecular beam epitaxial growth chamber comprises an optical window through which light is introduced into said growth chamber and irradiates the surface of said substrate during molecular beam epitaxial growth.