Abstract: A semiconductor laser array includes a p-GaAs substrate, a p-Ga.sub.1-x Al.sub.x As cladding layer, a Ga.sub.1-y Al.sub.y As active layer, an n-Ga.sub.1-z Al.sub.z As optical guide layer, an n-Ga.sub.1-x Al.sub.x As cladding layer and an n-GaAs cap layer formed by the liquid phase epitaxial growth method. A plurality of stripe shaped grooves are formed in the surface of the n-GaAs cap layer so that the bottom of the groove reaches the intermediate of the n-Ga.sub.1-z Al.sub.z As optical guide layer. A Ga.sub.1-b Al.sub.b As high resistance layer is filled in the plurality of stripe shaped grooves so that injecting current is divided into a plurality of paths, and each laser emitting region is optically, phase coupled to each other with a phase difference of zero degree.

Abstract: A semiconductor laser includes a current blocking layer formed on a substrate, a first cladding layer formed on the current blocking layer, an active layer formed on the first cladding layer, and a second cladding layer formed on the active layer. An indent is formed in the current blocking layer near the center of the laser element, and a V-shaped groove is formed in the current blocking layer across the indent. A gain guide structure is formed where the indent is formed, and an index guide structure is formed near the cleaved facet. A stable transverse mode laser emission is ensured without the influence of the return beam reflected from the disc surface, and the attendant mode competition noise is reduced.

Abstract: The disclosure is directed to an improved semiconductor laser device which includes a first light deriving optical waveguide connected approximately perpendicularly to a light exit face at one side, a second light deriving optical waveguide connected approximately perpendicularly to another light exit face at the other side and having an optical axis different from that of the first light deriving optical waveguide, and a light emitting optical waveguide subjected to optical coupling with a periodical diffraction grating for optical resonance, and connected to end portions of the first and second light deriving optical waveguides within the semiconductor laser device.

Abstract: A process for the production of semiconductor devices includes: (1) forming a thin semiconductor film containing no aluminum on a first semiconductor layer containing aluminum that is disposed on a substrate one or more (2) forming channels on said thin semiconductor film in such a manner that the channel or channels reach or go through said first semiconductor layer to expose a portion of said substrate, resulting in a channelled substrate for succeeding crystal growth thereon, and (3) producing by epitaxial growth crystalline layers on said channelled substrate by the use of a crystal growth solution having a supersaturation which is high enough to prevent said first semiconductor layer from undergoing meltback.