Abstract: A semiconductor laser device comprising a laser-oscillating optical waveguide composed of a control region which functions to absorb light and main regions which function to oscillate laser light, said control region being positioned in the center portion of said optical waveguide and said main regions being positioned on both ends of said control region, wherein said laser device further comprises a shunting means by which the ratio of the current Ig flowing to said control region to the total current It injected into said laser device is set to meet the inequality (1): ##EQU1## wherein Lg is the length of said control region and Lt is the length of said optical waveguide.

Abstract: A multilayered crystal structure in a semiconductor laser device contains an active layer for laser oscillation on a V-stripe channeled substrate having a current-blocking layer thereon. The active layer further includes regions by means of which carriers within the active layer are prevented from diffusing outside of the active layer. These regions are disposed facing each other with an optical waveguide therebetween which is formed by the absorption of light by the portions of the current-blocking layer which are positioned at both sides of the striped channel. The distance between the regions is narrower than the width of the optical waveguide in the vicinity of both facets and wider than the width of the optical waveguide inside of both facets.

Abstract: A semiconductor laser device comprising a single or a plurality of quantum well regions formed by a superlatticed structure which is composed of alternate layers consisting of thin GaAs layers and thin Al.sub.x Ga.sub.1-x As (0<x<1) layers, each of said layers having a thickness of five molecular layers or less and each of said quantum well regions having a thickness in the range of 100 .ANG. to 150 .ANG..

Abstract: An interferometric semiconductor laser device having a built-in effective refraction index difference, based on the absorption of light by a substrate, between the portion of the active layer corresponding to the inside area of a striped channel formed on the surface of said substrate and the portion of the active layer corresponding to the outside area of said striped channel, wherein regions, which are positioned between the active layer and the substrate in the outside area of said channel along a waveguide formed in the active layer corresponding to said channel, are different from each other in the distance between the active layer and the substrate, thereby creating a difference in the effective refraction index between the portions of the active layer corresponding to said regions.

Abstract: A semiconductor laser apparatus comprising: a semiconductor laser chip with a first light-emitting facet and a second light-emitting facet containing an interference effect-creating means therein for creating an interference effect within the resonator(s) thereof, a laser light-reflecting means for returning a part of the laser light emitted from the first light-emitting facet of said semiconductor laser chip to the first light-emitting facet, and a mounting base on which said semiconductor laser chip and said laser light-reflecting means are fixed in a parallel manner.

Abstract: A semiconductor laser device in which a double-heterostructure multi-layered crystal containing an active layer for laser oscillation is formed on a single crystal substrate having a channel composed of alternate channel portions with different widths and lengths, resulting in a plurality of alternate optical waveguides in said active layer corresponding to said alternate channel portions, said optical waveguides being optically coupled therebetween but being electrically separated from each other.

Abstract: A semiconductor laser comprising a middle-positioned active layer sandwiched between the lower-positioned active layer and the upper-positioned active layer, the refractivity of each of said lower- and upper- positioned active layers being slightly different from that of the middle-positioned active layer.

Abstract: A semiconductor laser device comprising a laser oscillation-operating area containing a first cladding layer, an active layer, an optical guiding layer and a second cladding layer in that order, wherein a striped impurity-diffusion region is formed into said second cladding layer from one facet to the other facet and a plurality of narrow strips of GaAs with a spaced pitch are formed in parallel with both facets in the region, except for the region corresponding to said striped diffusion region, which is positioned at the interface between the optical guiding layer and the second cladding layer.

Abstract: A semiconductor laser array which includes a plurality of active wave guide in a substantially parallel manner disposed on first and second laser opposing laser facets so as to be optically coupled and so that adjacent wave guides converse into one or more active wave guides on an opposing laser facet. The laser array exhibits stable operations and a high output power in a single narrow beam. The active wave guides have identical vertical modes and a phase difference of zero degrees.

Abstract: An optical semiconductor device comprising a GaAs substrate and a lamination of molecular layer units formed on said GaAs substrate, said molecular layer units being composed of binary compound semiconductors of InP, GaP and AlP.

Abstract: A semiconductor laser device comprises a superlatticed layer which is composed of alternate layers consisting of GAP thin layers and AlP thin layers. The superlatticed layer is formed as an active layer on a GaP substrate. The semiconductor laser device also is composed of two superlatticed cladding layers formed on either side of the active layer. The laser device of the present invention has an oscillation wavelength in the visible short-wavelength region.

Abstract: A semiconductor laser device comprises an active layer, a current blocking striped-channel formed below the active layer in such a manner that light in the active layer for laser oscillation is absorbed by both shoulders of the striped channel, this results in an index-guided optical waveguide being formed within the active layer. Mesa channels are formed outside of the optical waveguide in a manner to cut off. The active layer, the distance between the mesa-channels is greater than the distance between the shoulders of said striped channel.

Abstract: A semiconductor laser array device comprising an active layer for laser oscillation having a plurality of curved portions at substantially right angles to the resonance direction to thereby create a distribution of the refractive index between the curved portions and the flat portions of the active layer, resulting in a plurality of laser oscillation operation areas which are positioned between the curved portions of the active layer and which are optically coupled therebetween.

Abstract: An active layer for laser oscillation and optical guiding layers for guiding laser light sandwiching the active layer therebetween are included in the device. At least one of the optical guiding layers is formed by a superlattice, the optical refractive index of which is lower than that of the active layer. Further, the optical refractive index is gradually decreased in the direction from the portion of the optical guiding layer adjacent to the active layer, to the outside of the optical guiding layer.

Abstract: An optical semiconductor device comprising laminated thin layers made of two kinds of binary compounds to form a superlatticed optical waveguiding structure and a superlatticed active region structure, thereby achieving a quantum well effect.

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 compound resonator type semiconductor laser device comprising a multiple-layered crystal structure having a first laser operation area which contains a resonator for laser oscillation and a second laser operation area which contains a resonator a facet of which is shared with that of the resonator in the first laser operation area; and an electric current feeder for injecting a current into said multiple-layered crystal structure, and wherein said facet of the resonator in the first laser operation area, which is shared with the facet of the resonator in the second laser operation area, is covered with a protective film to attain a high reflectivity therein, the other facet of the resonator in the first laser operation area is covered with a protective film to attain a low reflectivity therein, and the other facet of the resonator in the second laser operation area is covered with a protective film to attain a high reflectivity therein.

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 array device comprising a plurality of index-guided lasing filaments formed in an active layer in a parallel manner, and an electrical current injection portion formed on the upper face of grown layers therefor the flat shape of the electrical current injection portion is asymmetrical with respect to any line which is parallel to the lasing filaments.

Abstract: A semiconductor laser comprising a substrate; a current blocking layer formed on said substrate; a striped channel formed in said current blocking layer on said substrate, said striped channel being narrow in the vicinity of the facets and being wide inside of the facets; an active layer, a portion of the active layer corresponds to the narrow portion of said striped channel being a plane to form a window region and another portion of the active layer corresponds to the wide portion of said striped channel being a crescent shape to form a laser operation area with a mesa-structure which is surrounded by burying layers to cut off current leakage from said laser operation area, the width of the mesa-portion of said laser operation area being not less than that of a current injection region formed within said striped channel.