Abstract: An optical information processing apparatus including a substrate of a transparent material, first and second optical waveguides formed on opposite faces of said transparent substrate, a light introducing device for introducing reflected light from an information writing medium into the first and second optical waveguides, and a detecting device for detecting reproduction signal, tracking error signal and focusing error signal based on the reflected light introduced into the first and second optical waveguides.

Abstract: A semiconductor apparatus comprises a step-shaped substrate and a multiple-layered crystal structure formed on the substrate, said multiple-layered crystal structure is of a superlatticed layer which is composed of alternate layers consisting of plural thin layers grown by molecular beam epitaxy.

Abstract: A semiconductor laser device comprising an active layer sandwiched between a first semiconductor layer and a second semiconductor layer, the forbidden bandgap of each of said first and second layers being larger than that of said active layer, wherein at least one of said first and second layers has a striped projection provided with two inclined surfaces; said layer is sandwiched between said active layer and a light absorption layer; and the thickness of said layer that corresponds to the inside of the center area of each of the two inclined surfaces is thick enough so that laser light cannot permeate into said absorption layer and the thickness of said layer that corresponds to the outside of the center area of each of the two inclined surfaces is sufficiently thin so that laser light can permeate into said absorption layer, whereby the thickness of a semiconductor layer that constitutes a double-heterostructure is not required to be precisely regulated so that the laser device is not restricted by product

Abstract: A semiconductor laser device, includes (1) a first semiconductor layer having a mesa-shaped stripe, (2) a current blocking layer applied on the first semiconductor layer except the top of the mesa-shaped stripe of the first semiconductor layer, the current blocking layer allowing the electric current to flow only through the mountain-shaped region, (3) a first cladding layer applied on the current blocking layer and on the top of the mountain-shaped stripe of the first semiconductor layer, and having charge carriers of the same type with that of the first semiconductor layer, (4) an active layer applied on the first cladding layer, and (5) a second cladding layer applied on the active layer, and having charge carriers of the type opposite to that of the first cladding layer, wherein the first cladding layer, the active layer and the second cladding layer compose a multilayer structure of the double heterojunction type for the laser excitation.

Abstract: A double-heterostructure multilayered crystal structure in a semiconductor laser device contains an active layer for laser oscillation. A striped etching-protective thin layer is formed on the double-heterostructure multilayered crystal. A striped-mesa multilayered crystal is formed on the striped etching-protective thin layer. A burying layer is formed on the double-heterostructure multilayered crystal outside of both the striped thin layer and striped-mesa multilayered crystal. This provides refractive index distributions within the active layer corresponding to the inside and the outside of the striped-mesa multilayered crystal. Further, it provides a striped structure which functions as a current path composed of the striped-mesa multilayered crystal.

Abstract: A semiconductor laser device with a stripe-channeled substrate and an active layer for laser oscillation disposed over the substrate comprising an optical waveguide; a striped mesa that is formed by the removal of the portions corresponding to the outside of said optical waveguide; and a multi-layered crystal that is grown into said removed portions, said multi-layered crystal including a plurality of burying layers and containing a pin-, pp-n- or pn-n- reverse bias junction, and a method for the production thereof comprising epitaxially growing a multi-layered crystal containing the active layer on a grown crystal that includes the stripe-channeled substrate; forming a striped mesa on the portion corresponding to said striped channel by the removal of the portions at both sides of said striped channel; and epitaxially growing a multi-layered crystal outside of said striped mesa, said multi-layered crystal including a plurality of burying layers and containing a pin-, pp-n- or pn-n- reverse bias junction.

Abstract: In a semiconductor laser device comprising In(Ga.sub.1-x Al.sub.x)P cladding layers and an active region which has one or more In(Ga.sub.1-y Al.sub.y)P (y<x) quantum well layers and which is sandwiched by said cladding layers, superlatticed structures having an altervative lamination of In(Ga.sub.1-x Al.sub.x)P layers and In(Ga.sub.1-y Al.sub.y)P layers are disposed in contact with said cladding layers and/or said quantum well layers.

Abstract: A semiconductor laser device comprising a substrate; a current blocking layer disposed on the substrate; a striped channel formed in a manner to reach the substrate through the current blocking layer; a striped mesa disposed on the area of the V-channel, the striped mesa being of a multi-layered crystal that is composed of a first cladding layer, an active layer, a second cladding layer, and a protective layer in that order; and burying layers having at least one of the following two, a pn-reverse bias junction and a high resistant crystal, the burying layer being formed on both sides of the striped mesa, wherein the protective layer is made of Ga.sub.1-x Al.sub.x As (x>O).

Abstract: A semiconductor laser device containing a laser oscillation-operating area comprising a superlatticed quantum well region which is composed of layers of GaAs alternating with layers of Al.sub.x Ga.sub.1-x As (0<x.ltoreq.1), where each of the layers has a thickness of several molecular layers or less;optical guiding layers consisting of Al.sub.y Ga.sub.1-y As (x.ltoreq.y.ltoreq.1) sandwiching the quantum well region, where the AlAs mole fraction varies continuously; andcladding layers covering the optical guiding layers.

Abstract: A semiconductor device is formed by sequentially forming a first clad layer, active layer, second clad layer, and cap layer from, for example, an AlGaAs layer with an AlAs mixing ratio of .gtoreq.0.4, on a substrate made of GaAs or the like by MBE, MOCVD or another high precision growth process. Then AlGaAs layer is selectively removed only in the vicinity of formed ridges, and in this part, grooves on two stripes are formed from the cap layer surface, leaving the second clad layer with an intact thickness of, for example, only 3000 .ANG.. An insulation layer made of, for example, SiN is then formed in the groove area and the AlGaAs layer region, thereby creating a current stripe structure, in which only two grooves provide for current passages, that is, the light-emitting regions.

Abstract: A method for the production of semiconductor devices comprising: subjecting a GaAs substrate with an oxidized film thereon to a degasification treatment, heating the substrate during a radiation treatment by a molecular beam within a pre-treatment chamber to remove the oxidized film from the substrate, and growing a phosphorous compound semiconductor layer on the substrate by molecular beam epitaxy within a growth chamber connected to the pre-treatment chamber.

Abstract: A semiconductor laser device comprises a substrate having a main striped channel for confining current therein and sub-striped channels formed in a parallel manner outside of the main striped channel. The width of the sub-striped channels is greater than that of the main striped channel. An active layer is provided for laser oscillation. The portion of the active layer corresponding to the sub-striped channels are formed into a concave portion. The portion of the active layer positioned between the concaved portions of the active layer results in a plane with a limited thickness.

Abstract: A V-channel inner stripe semiconductor laser device comprising a multi-layered growth crystal having an active layer for laser oscillation but no substrate, with a buffer layer formed on the multi-layered growth crystal thicker than all of the layers of the growth crystal, where the multi-layered growth crystal and buffer layer are sandwiched between an n-sided electrode and a p-sided electrode, wherein a pair of mesa-striped channels are formed outside of the V-channel to remove the outside of the optical waveguide formed in the active layer corresponding to the V-channel.

Abstract: An external resonator type semiconductor laser apparatus comprising a semiconductor laser device, a reflector positioned behind said laser device in a manner to face the light-emitting rear facet of said laser device, and a photodetector, for detecting the optical output of said laser device, positioned backward of said reflector, wherein a part of the laser light from said light-emitting rear facet is reflected by said reflector and the reflected light is then incident to said photodetector.

Abstract: A semiconductor laser includes a front mirror facet and a rear mirror facet. An Al.sub.2 O.sub.3 film coating is formed on the front mirror facet by electron beam evaporation so that the front mirror facet has a reflectance between 10 and 20%. A multi-layered coating is formed on the rear mirror facet so that the rear mirror facet has a reflectance higher than 90%.

Abstract: A semiconductor device having a superlattice composed of two kinds of semiconductor materials, wherein the lattice unit of said superlattice is composed of periodically laminated layers consisting of four or more kinds of thin layers which are different from each other in the combination of materials and thickness.

Abstract: A semiconductor laser device comprising a multi-layered semiconductor crystal containing an active region for laser oscillation, wherein the extended portions of said active region which are adjacent to both sides of one facet having the width of a selected value of said device constitute light-absorbing regions by which light in a high-order transverse mode is absorbed to a greater extent than that in a fundamental transverse mode, thereby achieving laser oscillation in a stable fundamental transverse mode up to a high output power.

Abstract: A semiconductor laser apparatus comprising a semiconductor laser device and a semiconductor device, both of which are fixed on a single mounting base with a spacing of several mm or less therebetween in such a manner that one of the side faces of said semiconductor device faces a laser-emitting facet of said semiconductor laser device in a parallel manner, the side face of said semiconductor device being a facet, at least a part of which is coated with a reflecting dielectric film functioning so as to have laser light from said semiconductor laser device return to said semiconductor laser device therefrom.

Abstract: A semiconductor laser comprising a substrate for crystal growth having a striped channel, an active layer for laser oscillation, a cladding layer containing Mg which is in contact with said active layer at the side of said striped channel substrate.

Abstract: A semiconductor laser device comprising: a ring-shaped resonator constituted by a square-shaped optical waveguide composed of four straight optical waveguide sides in which facing sides are positioned in a parallel manner and a reflecting mirror is formed at each of the four corners of said square-shaped optical waveguide in a manner to divide the intersection angle of two each of said four sides at each of said four corners into two equal parts, and a means, for releasing laser light from said ring-shaped resonator, which is disposed on or near a part or the whole area of at least one of said four sides of said square-shaped optical waveguide.