Abstract: A semiconductor laser device having an active layer, a pair of cladding layers interposing the active layer and a multi-quantum barrier provided between one of the pair of cladding layers and the active layer is provided. The multi-quantum barrier includes barrier layers and well layers being alternated with each other. Thickness, energy band gap, or impurity concentration of at least one of the barrier layers and well layers in the multi-quantum barrier changes with the distance from the active layer, thereby providing a stable function of reflecting carriers overflowing from the active layer back to the active layer.

Abstract: A semiconductor laser including a semiconductor substrate and a multilayer structure formed upon the semiconductor substrate, the multilayer structure including an active layer, a pair of cladding layers between which the active layer is interposed, and a current confinement layer for injecting a current into a stripe-shaped predetermined region of the active layer. The current confinement layer comprises a first current blocking layer formed in regions thereof excluding a region corresponding to the predetermined region of the active layer. The first current blocking layer has a refractive index higher than a refractive index of the pair of cladding layers and an energy band gap larger than an energy band gap of the active layer.

Abstract: A lateral mode control type of semiconductor laser has a high-yield structure having a long life and improved oscillation wavelength reproducibility. A diffusion limit layer formed of an undoped Ga.sub.0.5 In.sub.0.5 P layer and an undoped (Al.sub.0.6 Ga.sub.0.4).sub.0.5 In.sub.0.5 P layer is provided between a p-(Al.sub.0.6 Ga.sub.0.4).sub.0.5 In.sub.0.5 P clad layer and an undoped Ga.sub.0.5 In.sub.0.5 P active layer. The diffusion limit layer has a diffusion coefficient smaller than that of the clad layer. Impurity Zn diffused from the p-(Al.sub.0.6 Ga.sub.0.4).sub.0.5 In.sub.0.5 P clad layer during crystal growth or working is trapped in the undoped Ga.sub.0.5 In.sub.0.5 P layer almost entirely. A part of the impurity Zn diffuses in the undoped (Al.sub.0.6 Ga.sub.0.4).sub.0.5 In.sub.0.5 P layer thereunder but does not reach the undoped Ga.sub.0.5 In.sub.0.5 P active layer.

Abstract: A phase-locked laser array comprising a plurality of element regions for passing electric current into an active layer; and inter-element regions formed between the element regions. Each of the inter-element regions is so formed as to have two regions, i.e. a non-diffusion region at the center thereof and a diffusion regions disposed on both sides thereof, thereby rendering the refractive index in the non-diffusion region higher than that in the diffusion regions. The method of manufacturing the phase-locked laser array which is characterized by including a step growing an optical waveguide layer of superlattice on a portion of a second clad layer while diffusing impurities doped in the second clad layer into said optical waveguide layer, thereby forming a diffusion regions on both sides of the inter-element region.

Abstract: A multi-tip semiconductor laser comprises: a substrate; a cladding layer; an active layer formed of alkali-halide crystal on the cladding layer; at least a field emission tip formed on a surface of the substrate to have a substantially corn shape, the field emission tip being so arranged to confront the active layer; a vacuum space structure for providing a space between substrate and the cladding layer with the field emission tip confronting the active layer and for maintaining the space in a vacuum state; and an electrode structure for a producing electrostatic field between the field emission tip and the same in response to an external voltage supply such that the field emission tip emits an electron beam toward the active layer. The active layer may be doped and be made of organic crystal. It may further comprises a conducting layer covering at least a portion of said active layer. The active layer may be formed in a channel formed in the anode layer.

Abstract: A method of fabricating a semiconductor laser includes successively forming on a semiconductor substrate by crystal growth an active waveguide comprised of a compound semiconductor comprising a Group V element phosphorus, a thin-film layer comprised of a first-conductivity type compound semiconductor comprising a Group V element arsenic and a current blocking layer comprised of a second-conductivity type compound semiconductor comprising a Group V element arsenic. A mask is formed for selectively etching the current blocking layer in the form of a stripe. A buffer-etching step is formed on both the current blocking layer and the mask to expose a surface of the current blocking layer and the thin-film layer, the surface including a Group V element arsenic. An outer cladding layer comprising a first-conductivity type compound semiconductor having a Group V element arsenic is formed on the current blocking layer and the thin-film layer in an atmosphere having a Group V element arsenic.

Abstract: A semiconductor laser comprising an active waveguide formed of a compound semiconductor comprising a Group V element phosphorous, comprised of an active layer and two cladding layers that hold the active layer between them, and a current confinement structure formed on the active waveguide by the use of a compound semiconductor comprising Group V element arsenic. This semiconductor laser can achieve a small astigmatism, a low threshold current and a low operation current. Also disclosed is a method of fabricating a semiconductor laser having characteristic features that the crystal growth may be carried out only twice, the movement of the impurities in crystals does not easily occur, a regrowth interface with a very little defect can be readily obtained, and the structure wherein the outer cladding layer has a smaller width at its portion nearer to the active waveguide can be naturally formed.

Abstract: A hetero structure semiconductor laser of inner stripe type comprises an (Al.sub.x Ga.sub.1-x).sub.0.5 In.sub.0.5 P first cladding layer of a first conductivity type, a Ga.sub.0.5 In.sub.0.5 P or (Al.sub.x Ga.sub.1-x).sub.0.5 In.sub.0.5 P active layer, an (Al.sub.x Ga.sub.1-x).sub.0.5 In.sub.0.5 P second cladding layer of a second conductivity type different from the first conductivity type, an AlInP or (Al.sub.x Ga.sub.1-x).sub.0.5 In.sub.0.5 P confinement layer or a SiO.sub.2 having a stripe-like opening and having a refractive index lower than that of the first cladding layer, and an upper cladding layer having a band gap larger than that of the first cladding layer having a refractive index lower than that of the second cladding layer are formed successively on a GaAs substrate. Further, the width of the active layer may be narrowed as a stripe-like structure. Thus, astigmatism of a semiconductor laser becomes smaller and the threshold value of laser action becomes smaller.

Abstract: According to the structure of the invention, an AlGaInP cladding layer of one conductive type, an active layer, and an AlGaInP cladding layer of other conductive type greater in thickness in stripes are formed on a GaAs substrate, and an insulating film, AlGaInP or amorphous layer smaller in refractive index than the AlGaInP cladding layer are formed at both sides of the stripes, wherein the light can be confined and guided also in the direction parallel to the active layer, and the light can be index-guided both in the direction parallel to the active layer and in the direction vertical thereto, so that a laser having an extremely smaller astigmatism may be presented. What is more, the current blocking layer disposed at the outer side of the insulating film, AlGaInP or amorphous layer is high in thermal conductivity, and the heat generated in the vicinity of the active layer may be efficiently released.The invention also relates to the method of fabricating the laser composed in such structure.

Abstract: This invention presents a new soldering material comprising an indium layer formed on EFTE film for solder-mounting a semiconductor device onto a metal heat sink. This indium layer can be easily transferred onto the heat sink by pressure applied by a tool, without the aid of ultrasonic energy. This produces a highly immaculate surface of the indium layer transferred onto the heat sink, and achieves stable soldering strength of the soldered semiconductor device. This invention also offers a multi-layered soldering material comprising a thin layer of metal of which the melting point is higher than the soldering temperature, and two indium layers sandwiching said metal layer, formed on an EFTE film. This multi-layered soldering material can be easily transferred onto a metal heat sink by a pressure applying tool without the aid of ultrasonic energy resulting in the stable soldering of a semiconductor device even if it has surface irregularities, without causing an electrical leakage or short circuit.

Abstract: In a semiconductor laser, an AlGaInP cladding layer of one conductive type, an active layer, and an AlGaInP cladding layer of other conductive type greater in thickness in stripes are formed on a GaAs substrate, and an insulating film, AlGaInP or amorphous layer smaller in refractive index than the AlGaInP cladding layer are formed at both sides of the stripes, wherein the light can be confined and guided also in the direction parallel to the active layer, and the light can be index-guided both in the direction parallel to the active layer and in the direction vertical thereto, so that a laser having an extremely smaller astigmatism may be presented. In addition, the current blocking layer disposed at the outer side of the insulating film, AlGaInP or amorphous layer is high in thermal conductivity, and the heat generated in the vicinity of the active layer may be efficiently released.

Abstract: An optoelectronic integrated circuit includes an N.sup.+ type cladding layer, an N type cladding layer, an active layer smaller in band gap than the N type cladding layer and a P type waveguide greater in band gap than the active layer sequentially formed on a semi-insulating substrate, a P type cladding layer partially formed on the surface of the P type waveguide, a laser composed of these N.sup.+ type and N type cladding layers, active layer, waveguide and P type cladding layer, and an N type emitted layer wider in band gap than the P type waveguide formed partially on the surface of the P type waveguide, thereby composing a heterojunction bipolar transistor using the N type cladding layer as the collector and the P type waveguide as the base.

Abstract: A semiconductor laser in which an InGaAsP active layer serving as light emitting layer and formed in the shape of a stripe on the surface of a flat InP first clad layer, and an InP second clad layer that is wider than the InGaAsP active layer and formed on the InGaAsP active layer are buried in an InP burying layer. The stripe direction is the <011> direction, an etched mirror is formed in the vicinity of the end of the active layer, and an opto-electronic integrated circuit is formed by integrating the electric device and photo detecting device on the same substrate. The substrate is a semi-insulating substrate, and the electric device and photo detecting device are formed on the InGaAsp or InGaAs layer formed on the InP burying layer by crystal growth.