Abstract: There is provided a surface emitting laser device of fundamental lateral mode oscillation that suppresses a resistor increase and that is favorable in reliability. A GaAs layer 16 having such a thickness as to exhibit a high reflection factor with respect to oscillation wavelength is formed on an upper DBR mirror. In addition, a groove having such a depth that the GaAs layer located directly under it has such a thickness as to exhibit a low reflection factor with respect to oscillation wavelength is formed on the GaAs layer in such a position as to stride an extension line of a boundary between an Al oxide layer and an AlAs layer. As a result, laser oscillation can be conducted only in a post region surrounded by the groove.

Abstract: A method for fabricating a surface-emission semiconductor laser on a p-type substrate includes the step of interposing an Au film between an AuGeNi film or AuGe film of an n-side electrode and a compound semiconductor layer of an n-type DBR, followed by annealing to form an Au alloy in the n-side electrode. The presence of the Au alloy film improves the adherence between the n-side electrode and the compound semiconductor layer to improve an injection current vs. applied voltage characteristic.

Abstract: A semiconductor device including a substrate, a mesa post overlying the substrate and having a substantially cylindrical shape, a resin member surrounding the mesa post and a stress moderating member received in the mesa post for moderating stress between the mesa post and the resin member. The stress applied to the mesa post is reduced because the entire volume of the resin member is divided by the stress moderating member and each of the divided resin members reduces the stress.

Abstract: A surface emitting semiconductor laser device including a substrate, a bottom DBR, and a mesa post having a layer structure, the layer structure including a top DBR including a plurality of pairs, each of said pairs including an Al-containing high-reflectivity layer and an Al-containing low-reflectivity layer, an active layer structure sandwiched between the DBRs for emitting laser, and a current confinement layer disposed within or in a vicinity of one of the DBRs, the current confinement layer including a central current injection area and an annular current blocking area encircling the central current injection area, the annular current blocking area being formed by selective oxidation of Al in an AlxGa1−xAs layer (0.95≦X<1) having a thickness below 60 nm, the Al-containing low-reflectivity layer including Al at an atomic ratio not more than 0.8 and below 0.9.

Abstract: A semiconductor laser device includes a resonant cavity formed on a GaAs substrate, the resonant cavity including a quantum well (QW) active layer structure having a GaInNAs(Sb) well layer and a pair of barrier layers. The QW structure has a conduction band offset energy (&Dgr;Ec) equal to or higher than 350 milli-electron-volts (meV) between the well layer and the barrier layers, and each of the barrier layers a tensile strain equal to or lower than 2.5%.

Abstract: A surface emitting semiconductor laser device includes a GaAs substrate, and first and second laser sections consecutively and monolithically formed on the GaAs substrate. The second laser section has an active layer structure having a bandgap wavelength longer than the bandgap wavelength of the active layer structure of the first laser section. The second laser section is pumped by a first laser emitted by the first laser section to emit second laser.

Abstract: A semiconductor laser device comprising a substrate, a resonator overlying said substrate, a waveguide overlying said substrate and optically coupled to said resonator, and a diffraction grating formed on said resonator or said waveguide, said diffraction grating including slits or grooves formed on an Al-oxidized region of an Al-containing oxidized semiconductor layer, said Al-oxidized region being formed by selectively oxidizing Al in said Al-containing oxidized semiconductor layer. In the present invention, the difference between the refractive indices of the layer having the embedded grating and the Al oxide layer becomes larger to increase the coupling constant between laser beams and the grating. The decrease of the cavity length can increase the number of the devices obtainable from a single wafer.

Abstract: The semiconductor laser device the n-InP cladding layer, SCH-MQW active layer, p-InP cladding layer, and p-GaInAsP optical waveguide layer are respectively formed into a tapered shape on the n-InP substrate. The combination of oscillation parameters of the tapered shape, the grating pitch of a diffraction grating, an optical waveguide including an active layer, and the length of a resonator are adjusted so that laser beam including two or more oscillating longitudinal modes are output.

Abstract: A semiconductor laser device including an InP-based substrate, and a laser structure overlying said InP-based substrate and configured to form a ridge stripe, said laser structure having a plurality of compound semiconductor layers including at least one selectively-oxidized layer forming a current confinement structure, said selectively-oxidized layer including a pair of Al-oxidized peripheral areas and a non-oxidized central area sandwiched therebetween and forming a current path for said laser structure. The semiconductor laser device has a reduced threshold current and excellent lasing characteristics by the function of the oxidized layer or a current blocking layer.

Abstract: A vertical cavity surface emitting laser device and a vertical cavity surface emitting laser array are provided for suppressing heat generation in and an increased operating voltage of the device. The vertical cavity surface emitting laser device is formed with a bottom DBR mirror layer structure and a top DBR mirror layer structure on a semiconductor substrate. An active layer and a current confinement layer are interposed between the two mirror layer structures. A portion, including the top DBR mirror layer structure and an underlying region extending at least to a lower end surface of the current confinement layer, is formed in a columnar mesa structure. An upper end surface of the mesa structure has an area larger than a cross section of the mesa structure near the current confinement layer.

Abstract: A semiconductor laser device in which a ridge structure including a layer comprised of an Al-containing compound semiconductor is formed at an upper portion, with both side portions of the layer being oxidized, and the laser-beam emitting face of the ridge structure is a non-oxidized area. As this reduces the ratio of defective cleaved faces, the production cost of the semiconductor laser device becomes lower, and because of the lower threshold current, the degradation of the characteristics over a long operational period does not likely occur.

Abstract: A method including the steps of: consecutively depositing a first etch stop layer, a first compound semiconductor and a second compound semiconductor layer overlying a semiconductor substrate, the first etch stop layer, the first and second compound semiconductor layers having different compositions from one another, etching the first and second compound semiconductor layers until the etching stops at the first etch stop layer, and forming a semiconductor laser device including the first etch stop layer and the first and second compound semiconductor layers. The existence of the first compound semiconductor layer made of a material different from those of the second compound semiconductor layer and the etch stop layer enables the etching of the second compound semiconductor layer while controlling the etching depth thereof by using the etch stop layer.

Abstract: A distributed feedback semiconductor laser device including an active layer, a diffraction grating disposed in a vicinity of the active layer and having a substantially uniform space period and a distributed feedback function, and a functional layer disposed in a vicinity of the diffraction grating and the active layer and having a function of controlling a refractive index of the active layer, whereby the functional layer controls a lasing wavelength of the active layer. The functional layer of controlling the refractive index of the distributed feedback semiconductor laser device can generate a plurality of the lasing wavelengths different among one another and easily controllable.

Abstract: A method for manufacturing a semiconductor optical waveguide comprises the steps of forming a core layer having an Al content which monotonically increases from the central part thereof to the film surface, and selectively oxidizing the core layer to obtain a peripheral, oxidized region and a central, non-oxidized region acting as a waveguide. The waveguide is tapered to have a circular mode field at the distal end thereof for efficiently coupling with an optical fiber.

Abstract: A method for manufacturing a semiconductor optical waveguide comprises the steps of forming a core layer having an Al content which monotonically increases from the central part thereof to the film surface, and selectively oxidizing the core layer to obtain a peripheral, oxidized region and a central, non-oxidized region acting as a waveguide. The waveguide is tapered to have a circular mode field at the distal end thereof for efficiently coupling with an optical fiber.

Abstract: This invention gives birth to a semiconductor laser device which is equipped with a semiconductor substrate, a laser active layer with a first bandgap energy overlying the preceding semiconductor substrate, and a p-type cladding layer and an n-type cladding layer between which the preceding active layer is interposed. In addition, the referenced p-type cladding layer has a second bandgap energy exceeding 1.35 eV and remaining greater than the first bandgap energy. Direct bonding technique is adopted for fabricating the semiconductor laser device in question in place of epitaxial growth technique, because the cladding layer and active layer differ in lattice constant.

Abstract: A semiconductor laser is produced by forming a laser activation section and a light emitting section having an InGaAsP layer as a quantum well on a GaAs substrate according to metal organic chemical vapor deposition by using a selective area growth mask, in such a manner that the laser activation section and the light emitting section have different film thicknesses. The laser activation section includes a laser activation layer whose oscillation wavelength is set to 0.8 to 1.1 .mu.m, and the light emitting section includes an optical waveguide layer having a broader forbidden band than the laser activation layer.

Abstract: There are provided a semiconductor laser device equipped with improved reflectors at the opposite ends of the resonator and capable of preventing any rise in the laser oscillation threshold current and reduction in the quantum efficiency due to temperature rise and a laser module comprising such a semiconductor laser device that operates effectively and efficiently at high temperature and can be downsized at reduced cost. The reflector 23 or 26 disposed at either end of the resonator 22 of a semiconductor laser device 21 according to the invention have a reflectivity that increases with the oscillation wavelength of the device within a range (.lambda..sub.1 to .lambda..sub.1) as a function of the operating temperature of the device. A laser module 31 according to the invention comprises such a semiconductor laser device 21 as a principal component.