Abstract: A hetero crystalline structure consisting of semiconductor materials of a zincblende-structure and wurtzite-structure. For example, formed on a semiconductor substrate having a crystal face of (100) of the zincblende structure is a semiconductor material of the wurtzite-structure in its bulk state as a film of the same zincblende-structure as the semiconductor substrate.

Abstract: An optielectronic device comprising a substrate crystal whose crystal plane is a (n11) plane tilted from the (100) plane toward the [110] direction, or [110] direction where (n>1). When the substrate is applied to an AlGaInP semiconductor laser, the optical device can be cleaved into a rectangular shape, as in the case of a (100) substrate crystal, resulting in easy handling of the chips and also is effective for making the lasting wavelength shorter, lowering the threshold current density for lasing, improving the continuous lasing temperature, etc. Furthermore, semiconductor lasers of different lasing wavelengths can be prepared under good control. Furthermore, a doping efficiency having no dependence on a tilt angle can be obtained by proper selection of a dopant. For example, Si is suitable as an n-type dopant entering sites of group III atom on an (n11) A plane (n.gtoreq.2).

Abstract: A semiconductor laser having a double hetero structure comprises a cladding layer of In.sub.1-x-y Ga.sub.x Al.sub.y P.sub.1-z As.sub.z (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, 0.ltoreq.z.ltoreq.0.5, 0.5.ltoreq.x+y.ltoreq.1) and an active layer of a strained-layer-superlattice of In.sub.1-x-y Ga.sub.x Al.sub.y P.sub.1-z As.sub.z (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, 0.ltoreq.z.ltoreq.1, 0.ltoreq.x+y.ltoreq.1) system, thus enabling the lasing of wavelength ranges from infra-red to green.

Abstract: An opto-electronic device has an atomic layer superlattice semiconductor comprising different semiconductor materials periodically piled up, each material having an atomic layer thickness. The superlattice semiconductor has a bandgap different from an alloy semiconductor having equivalently the same composition as the former. In a semiconductor laser, as clad layers, the atomic layer superlattice semiconductor having equivalently the same composition as a Zn.sub.0.42 Cd.sub.0.58 S alloy semiconductor and a larger bandgap than the later is used, and a ZnSe.sub.0.94 S.sub.0.06 alloy semiconductor as an active layer is located between the cladding layers. The double-hetero structure semiconductor laser thus provided can perform the lasing at 470 nm at room temperature.

Abstract: A diffraction grating having a delineated crystallographic diffraction plane which ensuess from a procedure of alternately growing two kinds single crystal layers on a single crystal substrate into multilayers, exposing a crystallographic plane other than the plane of growth in the above-mentioned single crystal layers of the two kinds of single crystal layers in the exposed crystallographic plane; and a process for producing a diffraction grating mentioned above.