Abstract: A semiconductor laser device comprises a compound semiconductor substrate, a first cladding layer formed on the substrate, an active layer formed on the first cladding layer, made of In.sub.1-y (Ga.sub.1-x Al.sub.x).sub.y P material (0.ltoreq.x<1, 0.ltoreq.y<1), and a second cladding layer formed on the active layer. These first cladding layer, the active layer, and the second cladding layer forms a double heterostructure. A lattice constant of the active layer is larger than that of the substrate by 0.3% or more. The lattice constants of the first and second cladding layers are substantially equal to that of the substrate.

Abstract: Disclosed is a semiconductor light emitting device, comprising a semiconductor substrate, a double hetero structure portion formed on the front surface of the substrate and consisting of an InGaAlP active layer and lower and upper clad layers having the active layer sandwiched therebetween, a first electrode formed in a part of the surface of the double hetero structure portion, and a second electrode formed on the back surface of the substrate. A current diffusion layer formed of GaAlAs is interposed between the double hetero structure portion and the first electrode, said current diffusion layer having a thickness of 5 to 30 microns and a carrier concentration of 5.times.10.sup.17 cm.sup.-3 to 5.times.10.sup.18 cm.sup.-3.

Abstract: A visible light emitting semiconductor laser has a double-heterostructure section above the N-type GaAs substrate, which is composed of a nondoped InGaP active layer sandwiched between an N type InGaAlP cladding layer and a P type InGaAlP cladding layer. A P type InGaP thin-film layer formed on the P type cladding layer functions as an etching stopper. Formed sequentially on the etching stopper layer are a P type cladding layer and an N type GaAs current-blocking layer, which have a stripe-shaped groove section in and around their central portion. The groove section has an opening at the top and the bottom portion narrower than the opening, presenting an inverse-trapezoidal cross-sectional profile. This arrangement makes the width of the optical confinement region of the semiconductor laser narrower than that of the current injection region.

Abstract: A semiconductor light emitting device, especially, a light emitting diode includes a compound semiconductor substrate of a first conductivity type, an InGaAlP layer formed on the substrate and having a light emitting region, a GaAlAs layer of a second conductivity type formed on the InGaAlP layer and having a larger band gap than that of the InGaAlP layer, and an electrode formed on a part of the GaAlAs layer. The light emitting diode emits light from a surface at the electrode side except for the electrode. A current from the electrode is widely spread by the GaAlAs layer to widely spread a light emitting region.

Abstract: A semiconductor laser device using double heterostructure comprised of In.sub.x Ga.sub.y Al.sub.1-x-y P (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1), capable of preventing the leakage of the carriers and thereby reducing the threshold current, being operative with small threshold current density and at high temperature, and having a long lifetime. The device may include a double heterostructure formed on the GaAs substrate, comprised of In.sub.x Ga.sub.y Al.sub.1-x-y P (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) including an active layer, the active layer having an impurity concentration not greater than 5.times.10.sup.16 cm.sup.-3. The device may include a double heterostructure formed on the GaAs substrate, comprised of InGaP active layer and p-type In.sub.q (Ga.sub.1-z Al.sub.z).sub.q P (0.ltoreq.q.ltoreq.1, 0.ltoreq.z.ltoreq.1) cladding layer with a value of z between 0.65 and 0.75. The device may include a double heterostructure formed on the GaAs substrate, comprised of In.sub.x Ga.sub.y Al.sub.1-x-y P (0.

Abstract: A gain waveguide type semiconductor laser oscillating visible light has an N type GaAs substrate of, and a double-heterostructure provided above the substrate to include an InGaP active layer, and first and second cladding layers sandwiching the active layer. The first cladding layer consists of N type InGaAlP, whereas the second cladding layer consists of P type InGaAlP. A P type InGaP layer is formed as an intermediate band-gap layer on the second cladding layer. An N type GaAs current-blocking layer is formed on the intermediate band-gap layer, and has an elongated waveguide opening. A P type GaAs contact layer is formed to cover the current-blocking layer and the opening.

Abstract: A gain waveguide type semiconductor laser oscillating visible light has an N type GaAs substrate of, and a double-heterostructure provided above the substrate to include an InGap active layer, and first and second cladding layers sandwiching the active layer. The first cladding layer consists of N type InGaAlP, whereas the second cladding layer consists of P type InGaAlP. A P type InGaP layer is formed as an intermediate band-gap layer on the second cladding layer. An N type GaAs current-blocking layer is formed on the intermediate band-gap layer, and has an elongated waveguide opening. A P type GaAs contact layer is formed to cover the current-blocking layer and the opening.