Abstract: A vertical-cavity surface-emitting laser device. The vertical-cavity surface-emitting laser (VCSEL) device comprises one or more VCSELs with each VCSEL having a mode-control region thereabout, with the mode-control region forming an optical cavity with an effective cavity length different from the effective cavity length within each VCSEL. Embodiments of the present invention can be formed as single VCSELs and as one- or two-dimensional arrays of VCSELs, with either an index-guided mode of operation or an index anti-guided mode of operation being defined by a sign of the difference in the two effective cavity lengths.

Abstract: A semiconductor laser that selectively performs oscillations in different polarization modes has first and second laser regions on a substrate. The first laser region exhibits a gain spectrum in which one polarization mode is dominant and the second laser region exhibits a gain spectrum in which a different polarization mode is dominant. Current injected independently into the each laser region causes polarization mode oscillation competition. One of the different polarization mode oscillations is selected by, for example, injecting a minute modulated current into at least one of the first and second laser regions.

Abstract: The present invention provides a n-drive surface emitting laser comprised of an active region, a first mirror region having a first conductivity type, a second mirror region having a second opposite conductivity type, the first and second mirror regions being located on opposite sides of the light generation region, a buffer region having a second conductivity type, and a substrate having a first conductivity type. In the preferred embodiment the first conductivity type is n-type, thus the present invention provides a method of forming an n-drive semiconductor laser on an n-type substrate. Contact is made to the p-type mirror region via a tunnel junction formed by degeneratively doping the areas of the substrate region and the buffer region which abut each other. The tunnel junction is reverse biased so that current is injected through the degeneratively doped p-n junction formed by the n+ substrate and the p-type conducting layer.

Abstract: A thermally activated silica optical circuit switch that uses light from a light source, such as a laser, to heat various regions of the switch to produce a switching function. In one embodiment, the switch includes silica glass formed on a substrate, such as a silicon substrate, and at least one input waveguide and one output waveguide formed within the silica glass. A light source is then used to generate light that illuminates a path in the silica glass that couples a particular input waveguide to a particular output waveguide. The light from the light source has a wavelength that enables it to be substantially absorbed by the silica glass and substantially transmitted through the substrate. The illumination by the light increases the temperature and correspondingly the index of refraction of the silica glass in the path. A light signal is then able to travel through the coupled waveguides via the increased index of refraction of the silica glass within the path.

Abstract: A substantially n-type substrate structure having a p-type surface for use in semiconductor devices as a substitute for a p-type semiconductor substrate. The substrate structure comprises a substrate region and a buffer region. The substrate region is a region of n-type compound semiconductor, and includes a degeneratively n-doped portion adjacent its first surface. The buffer region is a region of compound semiconductor doped with a p-type dopant. The buffer region is located on the first surface of the substrate region and includes a surface remote from the substrate region that provides the p-type surface of the substrate structure. The buffer region also includes a degeneratively p-doped portion adjacent the degeneratively n-doped portion of the substrate region. The substrate structure includes a tunnel junction between the degeneratively n-doped portion of the substrate region and the degeneratively p-doped portion of the buffer region.

Abstract: Semiconductor diode lasers include an aluminum free active region including at least one active layer having a general composition In.sub.(1-x) Ga.sub.x As.sub.y P.sub.(1-y) where 0.ltoreq.y.ltoreq.1; two confinement layers bounding the active region and having a general composition In.sub.(1-x) (Ga.sub.(1-z) Al.sub.z)x P wherein aluminum content z may be zero; and a lower cladding layer, and at least one upper cladding layer adjacent the confinement layers. The cladding layers have the same general composition as the adjacent confinement layer, but always have a finite aluminum content. The aluminum content of the cladding layers is selected such that the cladding layers have a energy bandgap greater than the energy bandgap of the confinement layers.

Abstract: A semiconductor laser includes a first conductivity type GaAs substrate; a AlGaAs double heterojunction structure disposed on the GaAs substrate and including an upper cladding layer having a mesa ridge stripe with a side surface that makes an angle larger than 90.degree. with a front surface of the upper cladding layer; a first current blocking layer of first conductivity type AlGaAs; and a second current blocking layer of first conductivity type AlGaAs, the first and second current blocking layers covering the mesa ridge stripe. The Al compositions of the first and second current blocking layers are larger than that of the upper cladding layer, maintaining an equivalent refractive index of an active region higher than that of other portions of the semiconductor laser. As a result, the differences between the lattice constant of the second current blocking layer and the GaAs substrate or the AlGaAs upper cladding layer are smaller than in prior art semiconductor lasers.

Abstract: An optical device has an optical element 21 comprising a light-emitting region 1 and a light-detecting region 4 disposed closely to each other on a common substrate 9. Returning light L.sub.R from an irradiated medium which is irradiated with light L emitted by the light-emitting region 1 is detected by the light-detecting region 4. The returning light is applied to a light-detecting region 4 at an incident angle .alpha. in the range of 0.degree.<.alpha.<90.degree..

Abstract: A semiconductor laser package and method of fabrication including a vertical cavity surface emitting laser and a power monitoring system, such as a photodetector mounted on a mounting base. An optical element, such as a beam splitter, formed integral with the mounting base or as a separate element positioned on the mounting base in optical alignment with an emission generated by the vertical cavity surface emitting laser. The optical element characterized by reflecting a portion of the emission in the direction of the photodetector and allowing a portion of the emission to pass therethrough. An overmolded housing is positioned on the mounting base to enclose the vertical cavity surface emitting laser, the photodetector and the optical element.

Abstract: A photonic light emitting device comprising a relatively high refractive index photonic-wire semiconductor waveguide core in the form of an arcuate shape, linear shape and combinations thereof. The waveguide core is formed into a closed loop cavity for a light-emitting device or laser. The waveguide core is surrounded on all transverse sides by relatively low refractive index medium and comprises an active medium having major and minor sides and semiconductor guiding layers proximate the major sides. The active medium and the guiding layers are so dimensioned in a transverse direction relative to the path of light propagation through the core to provide dramatically increased spontaneous-emission coupling efficiency, leaading to low lasing threshold and high intrinsic modulation rates.

Abstract: In an optoelectronic component having a laser chip as a light transmitter and a lens coupling optics for defined emission of radiation generated in the laser chip, the lens coupling optics is arranged immediately in front of the laser chip and is adjusted and fixed in stable fashion in a simple way. The component is rationally manufactured in a wafer union. The laser chip is arranged on a common carrier between two carrier parts whose lateral surfaces neighboring the resonator faces of the laser chip are provided with mirror layers, and that are inclined at an angle of 45.degree. relative to the resonator faces. Thus the radiation generated in the laser chip is directed nearly perpendicularly upward to the surface of the common carrier and the lens coupling optics is arranged on at least the one carrier part such that the radiation generated in the laser chip impinges this lens optics nearly perpendicularly.

Abstract: Surface-emitting distributed feedback (SEDFB) lasers having a curved grating with a shape that produces good beam quality. A preferred shape is one for which the grating curves away from the center of the gain region of the laser. The use of the curved grating of the present invention produces good beam quality from broad area SEDFB lasers with high power and high efficiency. The present invention overcomes self-induced filament formation and dynamic instabilities that limit achievable beam quality. The present invention provides for a holographic method for fabricating curved gratings for the SEDFB lasers that is consistent with laser batch processing.

Abstract: A light-emitting diode or laser diode is provided which uses a Group III nitride compound semiconductor satisfying the formula (Al.sub.x Ga.sub.1-x).sub.y In.sub.1-y N, inclusive of 0.ltoreq.x.ltoreq.1, and 0.ltoreq.y.ltoreq.1. A double hetero-junction structure is provided which sandwiches an active layer between layers having wider band gaps than the active layer. The diode has a multi-layer structure which has either a reflecting layer to reflect emission light or a reflection inhibiting layer. The emission light of the diode exits the diode in a direction perpendicular to the double hetero-junction structure. Light emitted in a direction opposite to the light outlet is reflected by the reflecting film toward the direction of the light outlet. Further, the reflection inhibiting film, disposed at or near the light outlet, helps the release of exiting light by minimizing or preventing reflection. As a result, light can be efficiently emitted by the light-generating diode.

Abstract: An improved semiconductor structure is provided. The semiconductor structure comprises a first layer, the first layer having a restricted growth surface having a region with a transverse dimension D, the first layer having a first lattice constant L.sub.1 ; a first, last and at least one intermediate transition layers, the transition layers forming a transition region, the transition region disposed above the first layer, the transition region having a vertical thickness T, and where at least one of the transition layers has lattice constants between L.sub.1 and a second lattice constant L.sub.2 where the first transition layer has a lattice constant closer to the L.sub.1 than L.sub.2 and the last transition layer has a lattice constant closer to the L.sub.2 than L.sub.1 ; and a second layer disposed on the transition region, the second layer having the second lattice constant L.sub.2 ; wherein: the transition region has an average fractional change in lattice constant characterized by .kappa. where .kappa.

Abstract: An optical recording/reproducing apparatus has a laser diode and a semiconductor integrated circuit device for driving the laser diode. The semiconductor integrated circuit device has a driver circuit for producing a drive current to be supplied to a laser diode in accordance with an input signal representative of a laser beam power varying depending on a relative speed between a magneto-optical disk and a spot of a laser beam emitted by the laser diode on the optical disk. The driver circuit has a non-linear first operation range and a substantially linear second operation range subsequent to the first operation range. For a linear operation of the driver circuit, a level shifter circuit is connected to the driver circuit for applying a shift voltage to the driver circuit with a result that an excess output current is produced by the driver circuit even when the input signal is non-existent.

Abstract: An optical amplifying device for amplification of an optical signal incident to a photo diode comprises a laser device and an electrical feeding circuit. The laser device is so formed that it comprises one single laser device comprising a number of active regions or laser structures electrically connected in series within one and the same optical cavity.

Abstract: A semiconductor quantum well structure having at least two quantum wells, each having an electron quantum level, a heavy hole quantum level and a light hole quantum level. In the two quantum wells, only their respective heavy hole quantum levels or their respective light hole quantum levels coincide with each other. Further, there is a construction in which a barrier portion between the two quantum wells has a thickness and a band gap which allow connecting the wave functions of the respective electrons between the two quantum wells. Alternatively, the thickness and band gap of the barrier allow the connection between the quantum wells of the wave functions of those holes whose quantum levels coincide with each other. In order to set the hole quantum level to a desired quantum level, a specific construction imparts an appropriate strain to the quantum wells.

Abstract: A semiconductor light source for an optical transmitter which includes at least one DC supply unit and at least one AC supply unit, comprises a DC signal source connected to the DC supply unit in order to supply a drive signal thereto; and an AC signal source connected to the AC supply unit in order to supply a control signal thereto; wherein turning on or off an optical output by the semiconductor light source is controlled by using a control signal having the same electric polarity as the drive signal.

Abstract: Quantum carrier confinement in a wire-like region defined by intersecting layers is significantly enhanced by various structural modifications of a conventional quantum wire device. In that way, operation of the device at room temperature and above is made feasible.

Abstract: A semiconductor laser which does not cause a sudden failure due to an electric surge. A ridge that is formed by a GaAs buffer layer, an n-InGaP cladding layer which is lattice-matched to a GaAs substrate, a strained-quantum well active layer, a p-InGaP cladding layer which is lattice-matched to the GaAs substrate, a p-GaAs waveguide layer, a p-InGaP cladding layer which is lattice-matched to the GaAs substrate, and a p-GaAs cap layer is constructed on the n-GaAs substrate by being buried therein by an n-InGaP current-blocking layer. A device stripe is constructed by a current-injected region in the device and current-non-injected regions near facets.