Abstract: A method includes forming a semiconductor layer on a semiconductor substrate. The semiconductor layer is patterned to form a semiconductive structure. Each of widths of two ends of the semiconductive structure is wider than a width of a middle of the semiconductive structure. The semiconductive structure is doped to form a doped semiconductor structure. An isolation structure is formed to surround the doped semiconductor structure. A recessing process is performed such that two trenches are formed on the doped semiconductor structure, and first, second and third portions of an active region are formed on the semiconductor substrate. A first gate structure and a second gate structure are formed in the trenches such that the first portion and the third portion are partially spaced apart by the first gate structure, and the second portion and the third portion are partially spaced apart by the second gate structure.

Abstract: In an embodiment a light emitting diode includes an n-type n-layer, a p-type p-layer and an intermediate active zone configured to generate ultraviolet radiation, a p-type semiconductor contact layer having a varying thickness and a plurality of thickness maxima directly located on the p-layer and an ohmic-conductive electrode layer directly located on the semiconductor contact layer, wherein the n-layer and the active zone are each of AlGaN and the p-layer is of AlGaN or InGaN, wherein the semiconductor contact layer is a highly doped GaN layer, and wherein the thickness maxima have an area concentration of at least 104 cm?2.

Abstract: A semiconductor structure includes an active region, an isolation structure, a first gate structure, and a second gate structure. The active region is disposed over a semiconductor substrate and has a first portion, a second portion, and a third portion. The third portion is between the first portion and the second portion. A shape of the first portion is different from a shape of the third portion, in a top view. The isolation structure is disposed over the semiconductor substrate and surrounds the active region. The first gate structure is disposed between the first portion and the third portion of the active region. The second gate structure is disposed between the second portion and the third portion of the active region.

Abstract: A surface emitting laser includes a substrate, a lower contact layer disposed on the substrate, a semiconductor layer mesa including a lower reflector layer, an active layer, an upper reflector layer, and an upper contact layer which are laminated, in the order named, on the lower contact layer, an annular electrode disposed on the upper contact layer, and a light transmitting window situated inside the annular electrode to transmit laser light, wherein the upper reflector layer includes a first region and a second region, the first region being inclusive of an area situated directly below the electrode and the light transmitting window, the second region being inclusive of an area outside the mesa and inclusive of a surrounding area of the first region within the mesa, and wherein a proton concentration in the first region is lower than a proton concentration in the second region.

Abstract: A semiconductor laser diode includes multiple layers stacked along a first direction, in which the multiple layers include: a first multiple of semiconductor layers; an optical waveguide on the first multiple of semiconductor layers, in which the optical waveguide includes a semiconductor active region for generating laser light, and in which the optical waveguide defines a resonant cavity having an optical axis; and a second multiple of semiconductor layers on the optical waveguide region, in which a resistivity profile of at least one layer of the multiple layers varies gradually between a maximum resistivity and a minimum resistivity along a second direction extending orthogonal to the first direction, in which a distance between the maximum resistivity and the minimum resistivity is greater than at least about 2 microns.

Abstract: Various embodiments of a photonic device and fabrication method thereof are provided. In one aspect, a device includes a substrate, a current confinement layer disposed on the substrate, an absorption layer disposed in the current confinement layer, and an electrical contact layer disposed on the absorption layer. The current confinement layer is doped in a pattern and configured to reduce dark current in the device. The photonic device may be a photodiode or a laser.

Abstract: A device including one or more layers with lateral regions configured to facilitate the transmission of radiation through the layer and lateral regions configured to facilitate current flow through the layer is provided. The layer can comprise a short period superlattice, which includes barriers alternating with wells. In this case, the barriers can include both transparent regions, which are configured to reduce an amount of radiation that is absorbed in the layer, and higher conductive regions, which are configured to keep the voltage drop across the layer within a desired range.

Abstract: A device including one or more layers with lateral regions configured to facilitate the transmission of radiation through the layer and lateral regions configured to facilitate current flow through the layer is provided. The layer can comprise a short period superlattice, which includes barriers alternating with wells. In this case, the barriers can include both transparent regions, which are configured to reduce an amount of radiation that is absorbed in the layer, and higher conductive regions, which are configured to keep the voltage drop across the layer within a desired range.

Abstract: A device including one or more layers with lateral regions configured to facilitate the transmission of radiation through the layer and lateral regions configured to facilitate current flow through the layer is provided. The layer can comprise a short period superlattice, which includes barriers alternating with wells. In this case, the barriers can include both transparent regions, which are configured to reduce an amount of radiation that is absorbed in the layer, and higher conductive regions, which are configured to keep the voltage drop across the layer within a desired range.

Abstract: A semiconductor vertical resonant cavity light source includes an upper mirror and a lower minor that define a vertical resonant cavity. A first active region is within the vertical resonant cavity for light generation between the upper minor and lower mirror. The vertical resonant cavity includes an inner mode confinement region and an outer current blocking region. A depleted heterojunction current blocking region (DHCBR) is within the outer current blocking region of at least one of the upper minor, lower minor, and first active region. A conducting channel within the inner mode confinement region is framed by the DHCBR. The DHCBR forces current flow into the conducting channel during operation of the light source.

Abstract: A nitride semiconductor laser device includes: a stack, the stack including an n-type layer and a p-type layer each including a nitride semiconductor; an n-electrode electrically coupled to the n-type layer; a p-electrode electrically coupled to the p-type layer; and a thermally conductive portion disposed in contact with the p-type layer in a region which is different from the region where the p-electrode is connected, wherein the thermally conductive portion is electrically insulated from the p-electrode. Manufacturing steps specific to nitride semiconductors are employed to form the device. An optical apparatus, such as an optical disc device, a display device, or a lighting device includes such a nitride laser device and depends its functions thereto.

Abstract: A semiconductor light emitting device of one embodiment includes: a substrate; an n-type layer of an n-type nitride semiconductor on the substrate; an active layer of a nitride semiconductor on the n-type semiconductor layer; a p-type layer of a p-type nitride semiconductor on the active layer. The p-type layer has a ridge stripe shape. The device has an end-face layer of a nitride semiconductor formed on an end face of the n-type semiconductor layer, the active layer, and the p-type semiconductor layer. The end face is perpendicular to an extension direction of the ridge stripe shape. The end-face layer has band gap wider than the active layer. The end-face layer has Mg concentration in the range of 5E16 atoms/cm3 to 5E17 atoms/cm3 at a region adjacent to the p-type layer.

Abstract: A Vertical Cavity Surface Emitting Laser (VCSEL) capable of providing high output of fundamental transverse mode while preventing oscillation of high-order transverse mode is provided. The VCSEL includes a semiconductor layer including an active layer and a current confinement layer, and a transverse mode adjustment section formed on the semiconductor layer. The current confinement layer has a current injection region and a current confinement region. The transverse mode adjustment section has a high reflectance area and a low reflectance area. The high reflectance area is formed in a region including a first opposed region opposing to a center point of the current injection region. A center point of the high reflectance area is arranged in a region different from the first opposed region. The low reflectance area is formed in a region where the high reflectance area is not formed, in an opposed region opposing to the current injection region.

Abstract: Provided is a semiconductor laser, wherein (?a??w)>15 (nm) and Lt<25 (?m), where ?w is the wavelength of light corresponding to the band gap of the active layer disposed at a position within a distance of 2 ?m from one end surface in a resonator direction, ?a is the wavelength of light corresponding to the band gap of the active layer disposed at a position that is spaced a distance of equal to or more than ( 3/10)L and <( 7/10)L from the one end surface in a resonator direction, “L” is the resonator length, and “Lt” is the length of a transition region provided between the position of the active layer with a band gap corresponding to a light wavelength of ?w+2 (nm) and the position of the active layer with a band gap corresponding to a light wavelength of ?a?2 (nm) in the resonator direction.

Abstract: A VCSEL structure is provided. The VCSEL structure comprises a substrate. The structure may also include one or more conducting layers positioned on the substrate. There may be void spaces positioned between portions of the conducting layers to electrically isolate the portions. A method for fabricating the VCSEL structure is also provided.

Abstract: A VCSEL with undoped top mirror. The VCSEL is formed from an epitaxial structure deposited on a substrate. A doped bottom mirror is formed on the substrate. An active layer that includes quantum wells is formed on the bottom mirror. A periodically doped conduction layer is formed on the active layer. The periodically doped conduction layer is heavily doped at locations where the optical energy is at a minimum when the VCSEL is in operation. A current aperture is used between the conduction layer and the active region. An undoped top mirror is formed on the heavily doped conduction layer.

Abstract: A semiconductor laser apparatus includes, on a substrate, a first-conductivity type layer, an active layer, a second-conductivity type layer having a ridge extending along an optical waveguide direction, and a current blocking layer formed on sides of the ridge. The ridge is disposed to separate the substrate into a first region having a first width, and a second region having a second width greater than the first width, in a direction perpendicular to the optical waveguide direction. The second-conductivity type layer has a shock attenuating portion having a height greater than or equal to that of the ridge, on sides of the ridge. In the second region, a trench extending from an upper surface of the shock attenuating portion, penetrating at least the active layer, and reaching the first-conductivity type layer, is formed along the optical waveguide direction.

Abstract: A nitride semiconductor laser element exhibits high-speed responsiveness by largely reducing the capacitance of the nitride semiconductor laser element. The nitride semiconductor laser element includes an n-type semiconductor layer, an active layer and a p-type semiconductor layer each laminated on the main surface of the substrate. The nitride semiconductor laser element further includes a striped ridge portion formed in the p-type semiconductor layer, and pn-junctions of the semiconductor layer in the peripheral region remote from the ridge portion are broken by ion implantation to form an insulative region for reducing the capacitance of the element.

Abstract: A surface-emission laser diode includes an active layer, a pair of cavity spacer layers formed at both sides of the active layer, a current confinement structure defining a current injection region into the active layer, and a pair of distributed Bragg reflectors opposing with each other across a structure formed of the active layer and the cavity spacer layers, the current confinement structure being formed by a selective oxidation process of a semiconductor layer, the pair of distributed Bragg reflectors being formed of semiconductor materials, wherein there is provided a region containing an oxide of Al and having a relatively low refractive index as compared with a surrounding region in any of the semiconductor distributed Bragg reflector or the cavity spacer layer in correspondence to a part spatially overlapping with the current injection region in a laser cavity direction.

Abstract: A VCSEL with undoped top mirror. The VCSEL is formed from an epitaxial structure deposited on a substrate. A doped bottom mirror is formed on the substrate. An active layer that includes quantum wells is formed on the bottom mirror. A periodically doped conduction layer is formed on the active layer. The periodically doped conduction layer is heavily doped at locations where the optical energy is at a minimum when the VCSEL is in operation. A current aperture is used between the conduction layer and the active region. An undoped top mirror is formed on the heavily doped conduction layer.

Abstract: A laser diode capable of being easily mounted, and a laser diode device in which the laser diode is mounted are provided. A hole is disposed in a semiconductor layer, and a p-type electrode and an n-type semiconductor layer are electrically connected to each other by a bottom portion (a connecting portion) of the hole. Thereby, the p-type electrode has the same potential as the n-type semiconductor layer, and a saturable absorption region is formed in a region corresponding to a current path. Light generated in a gain region (not shown) is absorbed in the saturable absorption region to be converted into a current. The current is discharged to a ground via the p-side electrode and the bottom portion, and an interaction between the saturable absorption region and the gain region is initiated, thereby self-oscillation can be produced.

Abstract: The reliability of a buried hetero-structure semiconductor laser is improved by preventing an increase in oscillation threshold current and a decrease in external differential quantum efficiency in cases where the semiconductor laser is energized continuously under conditions of high temperature and high optical output. An optical semiconductor laser has an optical waveguide structure comprising an n-type cladding layer, an active layer and p-type cladding layers, and a current narrowing/blocking structure comprising a p-type blocking layer and an n-type blocking layer, wherein concentration of hydrogen contained in the p-type cladding layers is higher than concentration of hydrogen contained in the p-type blocking layer.

Abstract: A VCSEL which can be easily manufactured and can selectively suppress only high-order transverse mode oscillation is provided. The VCSEL includes a resonator, a first current confinement layer, and a second current confinement layer. The resonator includes an active layer having a light emitting region, and a pair of first multilayer reflector and a second multilayer reflector provided with the active layer in between, and resonate is generated in a given wavelength. The first current confinement layer has a current injection region is a region corresponding to the light emitting region, and is formed at a region including an antinode of a standing wave. The second current confinement layer has a current injection region with a diameter smaller than a diameter of the first current injection region and is formed at a region including a node standing wave.

Abstract: A VCSEL structure is provided. The VCSEL structure comprises a substrate consisting of a III-V material. The structure may also include one or more conducting layers positioned on said substrate. There may be void spaces positioned between portions of the conducting layers to electrically isolate the portions. A method for fabricating the VCSEL structure is also provided.

Abstract: A vertical cavity surface emitting laser diode (VCSEL) with a new structure is disclosed. The VCSEL of the invention provides the active layer, the first spacer layer, the tunnel junction, the second spacer layer burying the tunnel junction. Only the first spacer layer is ion-implanted to form a high-resistive region around the tunnel junction. The current injected into the second spacer layer is confined by the tunnel junction to reach the active layer, which reduces the increase of the parasitic resistance of the device. The high-resistive region around the tunnel junction reduces the parasitic capacitance of the device.

Abstract: A method for manufacturing a semiconductor device having a compound semiconductor layer that is provided on a substrate and includes a cladding layer of a first conductivity type, an activation layer, a cladding layer of a second conductivity type that is the opposite of the first conductivity type, includes the steps of: forming a diffusion source layer on the compound semiconductor layer; forming a first diffusion region in the compound semiconductor layer by carrying out a first heat treatment, so that the first diffusion region includes a light emitting facet for emitting light from the activation layer; removing the diffusion source layer; forming a first SiN film having a refractive index of 1.9 or higher on the compound semiconductor layer; and turning the first diffusion region into the second diffusion region by carrying out a second heat treatment.

Abstract: Current channels, blocking areas, or strips in a semiconductor laser are used to channel injected current into the antinodal region of the optical standing wave present in the optical cavity, while restricting the current flow to the nodal regions. Previous devices injected current into both the nodal and antinodal regions of the wave, which is fed by the population inversion created in the active region by the injected electrons and holes, but inversion created in the nodal regions is lost to fluorescence or supports the creation of undesirable competing longitudinal modes, causing inefficiency. Directing current to the antinodal regions where the electric field is at its maximum causes a selected longitudinal mode to preferentially oscillate regardless of where the longitudinal mode lies with respect to the gain curve. In one embodiment, exacting fabrication of the Fabry-Perot cavity correlates the current channels to antinodal regions, vis-a vis current blocking areas, strips or segmented layers.

Abstract: The present invention provides a structure of a light-emitting device which prevents the inter diffusion of impurities from the high-doped n-type InP substrate to a p-type current blocking layer. The substrate of the invention is highly doped with sulfur (S) to obtain high quality surface whose etch pit density (EPD) is less than 100 cm?2. The device includes such substrate, an optical guiding portion with an active layer, and a current blocking portion provided so as to bury the guiding portion. This current blocking portion includes, from the side of the substrate, a p-type layer, an n-type layer and another p-type layer. The device of the invention provides an n-type layer that is moderately doped with silicon between the n-type substrate and the p-type current blocking layer to prevent the inter diffusion of impurities from the substrate to the p-type layer.

Abstract: In one embodiment of the invention, in a semiconductor laser in which a first conductivity type lower cladding layer, an active layer that includes a quantum well layer, and a second conductivity type upper cladding layer are formed in this order on a semiconductor substrate, a dopant concentration of the lower cladding layer is not more than 4.0×1017/cm3, and a resonator length is not less than 1500 ?m.

Abstract: A first and second semiconductor laser, which comprise buffer layers, cladding layers, quantum well active layers, and cladding layers integrated on the substrate and have a stripe geometry, are integrated on a common substrate, with the quantum well active layers in the vicinity of the cavity facets disordered by impurity diffusion. Relationships ?1>?b1, ?2>?b2, ?1>?2, and E1?E2 are satisfied, where ?1 and ?2 are defined, respectively, as the emission wavelengths of the active layers of the first and second semiconductor lasers, E1 and E2, respectively, as the forbidden band energies of the buffer layers of the first and second semiconductor lasers, and ?b1 and ?b2 respectively as the wavelengths corresponding to the forbidden band energies of the buffer layers of the first and second semiconductor lasers.

Abstract: Disclosed is a semiconductor laser. The semiconductor laser includes a semiconductor chip that includes an active layer and emits radiation in a main radiating direction. The active layer is structured in a direction perpendicular to the main radiating direction to reduce heating of the semiconductor chip by spontaneously emitted radiation. The active layer includes a region provided for optical pumping by a pump radiation source. The optically pumped region of the active layer is surrounded by a region having, in a direction perpendicular to the main radiating direction, a periodic structure that forms a photonic crystal in which radiation having the emission wavelength is not capable of propagation.

Abstract: A surface-emission laser diode includes an active layer, a pair of cavity spacer layers formed at both sides of the active layer, a current confinement structure defining a current injection region into the active layer, and a pair of distributed Bragg reflectors opposing with each other across a structure formed of the active layer and the cavity spacer layers, the current confinement structure being formed by a selective oxidation process of a semiconductor layer, the pair of distributed Bragg reflectors being formed of semiconductor materials, wherein there is provided a region containing an oxide of Al and having a relatively low refractive index as compared with a surrounding region in any of the semiconductor distributed Bragg reflector or the cavity spacer layer in correspondence to a part spatially overlapping with the current injection region in a laser cavity direction.

Abstract: Embodiments provide a vertical external cavity surface emitting laser (VECSEL) that may provide a uniform current density in an active layer using a double current injecting channel. The surface emitting laser device may include a double channel current injection structure for uniformly applying current to an active layer, wherein the double channel current injection structure may include: a first current injection channel, which may allow current to be injected toward a central portion of an aperture, which may be a light beam output region formed in the active layer, and may have a smaller diameter than the aperture: and a second current injection channel, which may allow current to be injected toward an edge of the aperture and may be located around the aperture.

Abstract: A laser diode capable of effectively inhibiting effects of return light is provided. A laser diode includes a substrate, and a laminated structure including a first conductive semiconductor layer, an active layer having a light emitting region, and a second conductive semiconductor layer having a projecting part on the surface thereof, on the substrate, wherein a return light inhibition part is provided on a main-emitting-side end face, and effects of return light in the vicinity of lateral boundaries of the light emitting region are inhibited by the return light inhibition part.

Abstract: A structure of an optical switch makes the optical switch capable of receiving broadband signals. And the manufacturing procedure is simplified.

Abstract: A vertical cavity surface emitting laser (VCSEL) is disclosed that has a relatively low vertical resistance between the Ohmic contact to the upper distributed Bragg reflector (DBR) and the active layer, and a structure to substantially confine the current flow to the laser cavity so that the VCSEL can produce a more efficient and substantially single-mode output. In particular, the VCSEL includes a substrate, a lower DBR disposed over the substrate, an active layer disposed over the lower DBR, and an upper DBR. The upper DBR includes a groove and an Ohmic contact situated within the groove to lower the vertical resistance between the contact and the active layer. An ion implanted layer is also formed along the side wall of the active layer to substantially confine the current flow to the laser cavity.

Abstract: A surface emitting laser device is disclosed that is able to selectively add a sufficiently large loss to a high order transverse mode so as to efficiently suppress a high order transverse mode oscillation and to oscillate at high output in a single fundamental transverse mode. The surface emitting laser device includes a first resonance region that includes an active layer and spacer layers, two distributed Bragg reflectors that sandwich the resonance region, and a current confinement structure that defines a current injection region for the active layer. At least one of the distributed Bragg reflectors includes a second resonance region arranged in the current injection region excluding a predetermined region surrounding a center of the current injection region.

Abstract: A VCSEL with current confinement achieved by an oxide insulating region and by an ion implant region. An annular shaped oxide layer is formed, and a gain guide ion implant is formed. The ion implant gain guide includes a central region having high conductivity. The VCSEL further includes first and second mirrors that are separated by an optical path of at least one wavelength. Furthermore, the oxide insulating region beneficially has a optical path of less than ¼ wavelength. The ion implanted spatial region is beneficially concentrically aligned with the oxide insulating region.

Abstract: It makes possible to inject a current into the current confinement region substantially uniformly. A surface emitting type optical semiconductor device includes a semiconductor active layer provided above a substrate; a first and second reflecting mirror layers sandwiching the semiconductor active layer to form an optical cavity in a direction perpendicular to the substrate; a plurality of current confinement regions provided in the second reflecting mirror layer so as to be separated by an impurity region having impurities; a semiconductor current diffusion layer provided on the second reflecting mirror layer so as to cover the current confinement regions; and an electrode portion which injects a current into the semiconductor active layer. The electrode portion comprising a first electrode provided on the semiconductor current diffusion layer so as to surround the current confinement regions and a second electrode provided on an opposite side of the substrate from the semiconductor active layer.

Abstract: A surface-emitting type semiconductor laser includes a substrate, a first distributed Bragg reflection type mirror formed above the substrate, an active layer formed above the first mirror, a second distributed Bragg reflection type mirror formed above the active layer, and an insulation layer having an opening section that is formed in one of the first and second mirrors, wherein light generated from the active layer is emitted as a lower order mode laser beam lower order modeor a higher order mode laser beamhigher order mode, and the first mirror is formed with a number of pairs greater than the number of pairs of the second mirror such that the lower order mode laser beamlower order mode can be emitted in an upward direction of the substrate, and the opening section in the insulation layer is formed to have a size that enables the higher order mode laser beamhigher order mode to be emitted in a downward direction of the substrate.

Abstract: Methods for producing surface-emitting semi-conductor lasers with tunable waveguiding are disclosed. The laser comprises an active zone containing a pn-transition, surrounded by a first n-doped semiconductor layer and at least one p-doped semiconductor layer. In addition to a tunnel junction on the p-side of the active zone, the tunnel junction borders a second n-doped semi-conductor layer with the exception of an area forming an aperture. An n-doped layer is provided between the layer provided for the tunnel junction and the at least one p-doped semiconductor layer. The tunnel junction may be arranged in a maximum or minimum of the vertical intensity distribution of the electric field strength. This enables surface-emitting laser diodes to be produced in high yields with stabilization of the lateral single-mode operation, high performance and wave guiding properties.

Abstract: A structure of an optical switch makes the optical switch capable of receiving broadband signals. And the manufacturing procedure is simplified.

Abstract: A surface emitting laser having a substrate with top and bottom surfaces; a first stack of mirror layers of alternating indices of refraction located upon the top surface of the substrate; and active layer disposed over the first stack; a second stack of mirror layers of alternating indices of refraction disposed over the active layer and a recessed portion located centrally in the second stack extending through at least some of the second stack of mirror layers for improving the spectral width characteristic of the laser.

Abstract: A laser diode includes a substrate having a lattice constant of GaAs or between GaAs and GaP, a first cladding layer of AlGaInP formed on the substrate, an active layer of GaInAsP formed on the first cladding layer, an etching stopper layer of GaInP formed on the active layer, a pair of current-blocking regions of AlGaInP formed on the etching stopper layer so as to define a strip region therebetween, an optical waveguide layer of AlGaInP formed on the pair of current-blocking regions so as to cover the etching stopper layer in the stripe region, and a second cladding layer of AlGaInP formed on the optical waveguide layer, wherein the current-blocking regions having an Al content substantially identical with an Al content of the second cladding layer.

Abstract: A nitride based semiconductor laser diode device comprising a selective growth mask with a grating structure is proposed. The island-like stacked epitaxial layers including the P-type cladding layer is formed from the selective growth mask upon the active layer of the semiconductor laser structure. This proposed structure can reduce the strain by the deformation due to the isolate structure. Thus, increase of thickness of the cladding layer and/or increase of composition difference can be achieved without crack existing in the island-like stacked epitaxial layers. The optical confinement can be effectively improved.

Abstract: The present invention provides a complex optical device capable of decreasing electric power consumption, generating a high quality laser, and modulating the laser without degradation. The complex optical device includes a laser diode element (LD) and an electroabsorption modulator element (EAM) which are formed on the same substrate and optically coupled with each other. Both of the LD and the EAM are formed from a semiconductive upper cladding layer having a first conductive type, an insulating core layer, and a semiconductive lower cladding layer having a second conductive type opposite to the first conductive type. The electrical isolation layer extending through the core layer from the surface of the upper cladding layer up to the surface of the substrate is formed by an ion injection at an area between the LD and the EAM to isolate the LD and the EAM electrically.

Abstract: A system and method for providing a single mode VCSEL (vertical cavity surface emitting laser). A lower mirror is formed on a substrate. An active region including one or more quantum wells is formed over the lower mirror. The upper mirror formed over the active region can include multiple layers and may be formed to be have substantially isotropic conductivity. The layers in the upper mirror can include a lightly doped DBR layer, a heavily doped second layer including an isolation region, and a third heavily doped DBR layer. The active region may include conduction layers, which may be periodically doped, to improve conductivity and reduce free carrier absorption.

Abstract: In a semiconductor laser 1, a current blocking layer 19 covers a p-type 2nd cladding layer 17 and a p-type cap layer 18 that extend in a lengthwise direction of an optical resonator, at both a light-emission end and an end opposite the light-emission end, to thus form non-current injection regions in an optical waveguide. By making current blocking layer 19 at the light-emission end large enough that carriers flowing from a current injection region do not reach the light-emission end surface, the light intensity distribution in the near field at the light-emission end surface is strongly concentrated, allowing the horizontal divergence angle of an emerging laser beam to be enlarged. This structure makes it possible to enlarge the horizontal divergence angle independently after having optimized the thickness of cladding layers and the size of the current injection region.

Abstract: A semiconductor laser has implantation regions that are effective as mode-selective regions in addition to current diaphragms in the edge region of a mesa. As a result, the inner opening of the current diaphragms can be chosen to be larger than in the prior art. This leads to a low ohmic and thermal resistance and enables a high output power.

Abstract: The invention relates to a vertical cavity surface emitting laser and method for fabricating the same. The vertical cavity surface emitting laser of the invention comprises: a substrate, a first reflector, an active layer, a second reflector, a first electrode layer and a second electrode layer. The second reflector has a first confinement layer with a first aperture and a second confinement layer with a second aperture. The second aperture is smaller than the first aperture. According to the invention, because the second confinement layer is formed by implanting oxygen ion into the second reflector and heating to let the oxygen ion and Al content in the second reflector react to form an oxide layer, the second confinement layer can be used as an optical and electronic confinement layer. Therefore, the width and depth of the second confinement layer can be achieved precisely and easily.