Abstract: A nitride semiconductor laser element capable of controlling the lateral confinement of light with a good reproducibility, the nitride semiconductor element comprising an n-type cladding layer (3), an MQW light emitting layer (4) formed on the cladding layer (3), a p-type cladding layer (5) and a p-type contact layer (6) formed on the light emitting layer (4), and an ion implantation light absorbing layer (7) formed, by introducing carbon, in regions other than a current passing region (8) in the cladding layer (5) and the contact layer (6).

Abstract: An optical pickup device of the present invention includes a substrate having at least a major surface, a semiconductor laser provided on the surface of the substrate for emitting laser beam, a reflection-type diffraction grating oriented to the semiconductor laser for splitting the laser beam into at least three beams and reflecting them upward, a hologram for receiving the three beams reflected from the reflection-type diffraction grating, and an objective lens for converging onto an optical recording medium the three beams transmitted by the hologram. The three beams reflected from the optical recording medium are focused by the hologram and directed onto the photodetector from the above.

Abstract: A semiconductor laser device including an n-type cladding layer, an active layer, a p-type cladding layer having a ridge portion, an n-type optical confinement layer formed on the flat portion and side surfaces of the ridge portion of the p-type cladding layer, and an n-type current blocking layer formed on the n-type optical confinement layer in this order. The optical confinement layer is composed of a low resistivity layer doped with n-type impurity, which has a smaller refractive index than the p-type cladding layer and a bandgap energy greater than the energy of lasing light. The optical confinement layer has an impurity concentration of 5.times.10.sup.7 cm.sup.-3 or less. The n-type current blocking layer has a thickness of 0.4 .mu.m or less.

Abstract: In an optical pickup apparatus, a laser beam emitted from a semiconductor laser device is reflected upward by a reflecting member, transmitted through a transmission type diffraction grating and split into at least three beams, and which beams are transmitted through a transmission type holographic optical element and condensed onto an optical recording medium by a condenser portion. A return beam reflected by the optical recording medium passes through the condenser portion and diffracted not to impinge upon the transmission type diffraction grating by the holographic optical element and directed to a photodetector portion of a light receiving device. The semiconductor laser device and the light receiving device are disposed in a mount member.

Abstract: A semiconductor laser with a self-sustained pulsation is disclosed in which a first cladding layer of first conductive type, an active layer and a second cladding layer of second conductive type having a striped ridge are formed in that order on a semiconductor substrate of first conductive type. The first and second cladding layers have a refractive index smaller than and a band gap larger than the active layer. A saturable optical absorbing layer having a band gap of energy substantially equal to the energy corresponding to lasing wavelength is formed in both the first and second cladding layers. Further, a barrier layer having a refractive index smaller than and a band gap larger than the first and second cladding layers is formed between the first cladding layer and the active layer and/or between the active layer and the second cladding layer.

Abstract: In a semiconductor laser device comprising an n-type cladding layer, an active layer formed on the cladding layer, a p-type cladding layer formed on the active layer, and a p-type saturable light absorbing layer provided in the p-type cladding layer, the current confinement width for confining current injected into the active layer being W, the thickness d.sub.a of the active layer, the optical confinement factor .GAMMA..sub.a of the active layer, the thickness d.sub.s of the saturable light absorbing layer, the optical confinement factor .GAMMA..sub.s of the saturable light absorbing layer, and the light spot size S on a facet of the semiconductor laser device are so set as to satisfy a predetermined relationship. The reflectivity on a light output facet is set in the range of 10 to 20%.

Abstract: The present invention is directed to a semiconductor laser device in which an active layer is constituted by a quantum well layer having a structure in which well layers and barrier layers which are formed on a GaAs substrate are alternately layered, cladding layers are provided so as to interpose the active layer, the value of a strain on each of the well layers is -0.8% to -1.5%, the thickness of a well layer is from 80 .ANG. to 180 .ANG., the value of strain on each of the barrier layers is +0.5% to +1.0%, the thickness of the barrier layer is 20 .ANG. to 60 .ANG., and the respective numbers of layered well layers and barrier layers are 2 to 4.

Abstract: A semiconductor laser with a self-sustained pulsation is disclosed in which a first cladding layer of first conductive type, an active layer and a second cladding layer of second conductive type having a striped ridge are formed in that order on a semiconductor substrate of first conductive type. The first and second cladding layers have a refractive index smaller than and a band gap larger than the active layer. A saturable optical absorbing layer having a band gap of energy substantially equal to the energy corresponding to lasing wavelength is formed in both the first and second cladding layers. Further, a barrier layer having a refractive index smaller than and a band gap larger than the first and second cladding layers is formed between the first cladding layer and the active layer and/or between the active layer and the second cladding layer.

Abstract: A semiconductor laser with a self-sustained pulsation is disclosed in which a first cladding layer of first conductive type, an active layer and a second cladding layer of second conductive type having a striped ridge are formed in that order on a semiconductor substrate of first conductive type. The first and second cladding layers have a refractive index smaller than and a band gap larger than the active layer. A saturable optical absorbing layer having a band gap of energy substantially equal to the energy corresponding to lasing wavelength is formed in both the first and second cladding layers. Further, a barrier layer having a refractive index smaller than and a band gap larger than the first and second cladding layers is formed between the first cladding layer and the active layer and/or between the active layer and the second cladding layer.

Abstract: A semiconductor laser includes an oscillation layer comprising a first clad layer, an active layer and a second clad layer which are comprised of gallium aluminum arsenide and deposited, in this order, on a semiconductor substrate. A buried cap layer in a stripe geometry for narrowing a width of a current path is deposited on a second clad layer. A burying layer comprised of II-VI compound such as zinc selenide, zinc sulfide and the like is formed on the second clad layer other than the portion on which the cap layer is formed, so that the cap layer is buried. The buried layer is formed utilizing a low temperature deposition such as a molecular beam epitaxy.