Abstract: Semiconductor substrate is disclosed having quantum wells having first bandgap, and quantum wells having second bandgap greater than first bandgap. Semiconductor structure is disclosed comprising substrate having quantum wells having given bandgap, other quantum wells modified to bandgap greater than given bandgap. Semiconductor substrate is disclosed comprising wafer having quantum wells, section of first bandgap, and section of second bandgap greater than first bandgap. Method for forming semiconductor substrate is provided, comprising providing wafer having given bandgap, depositing dielectric cap on portion and rapid thermal annealing to tuned bandgap greater than given bandgap. Semiconductor structure is disclosed comprising substrate having quantum wells modified by depositing cap and rapid thermal annealing to tuned bandgap greater than given bandgap.

Abstract: A method for producing a multi-wavelength semiconductor laser device includes the steps of: forming a nitride epitaxial layer on a substrate for growth of a nitride single crystal; separating the nitride epitaxial layer from the substrate; attaching the separated nitride epitaxial layer to a first conductivity-type substrate; selectively removing the nitride semiconductor epitaxial layer to expose a portion of the first conductivity-type substrate and to form a first semiconductor laser structure; and sequentially forming second and third semiconductor laser structures on the exposed portion of the first conductivity-type substrate.

Abstract: A method, an apparatus, and a module for producing dual beam from a single laser diode provide for means of simultaneously pumping two individual gain media with orthogonal polarizations. A beam splitter splits the emissive laser beam into two portions based on the polarization. A polarization control element or mechanism adjusts the polarization and the intensity ratio of the separated beam portions. Applications to monolithic microchip lasers include generating new wavelengths based on intracavity beam combining and mixing.

Abstract: One embodiment of the present invention provides a system that facilitates adjusting the wavelengths of lasers via temperature control. This system includes a chip with an active face upon which active circuitry and signal pads reside. A thermal-control mechanism provides localized thermal control of two lasers mounted upon the active face of the chip. By individually controlling the temperature of the lasers, the thermal-control mechanism controls the wavelengths emitted by each respective laser. By creating a temperature gradient that causes a temperature difference between two or more lasers, the system can cause the lasers to emit different wavelengths.

Abstract: A method for reducing speckle noise of a monolithic microchip laser with intracavity beam combining and sum frequency mixing is based on time averaging of uncorrelated speckle patterns generated from a large number of independent longitudinal modes and comprises schemes including selection of gain media and nonlinear optical materials to support broadband sum frequency mixing; adoption of gain-conjugated and/or chirped mirrors for flat-top spectra and/or mode phase diversification; multimode laser operation introduced by RF modulation; and multiplication of source modes in frequency mixing process featured with degeneration free and narrowed/uneven intervals. A device and an apparatus for generating low speckle noise red, green, blue lasers adaptable for color display systems are developed based on the inventive method.

Abstract: A lightweight, compact image projection module, especially for mounting in a housing having a light-transmissive window, is operative for causing selected pixels in a raster pattern to be illuminated to produce an image of high resolution of VGA quality or higher in color. A laser beam focusing arrangement aligns a mechanical axis of a focusing lens with an optical axis along which a laser beam is directed to reduce pointing errors.

Abstract: A first semiconductor laser emitting light with a first wavelength and a second semiconductor laser emitting light with a second wavelength are formed on an identical substrate. Each of the semiconductor lasers includes: a doublehetero structure in which at least a first-conductivity-type cladding layer, an active layer and a second-conductivity-type cladding layer are stacked in this order; and a ridge waveguide including at least an upper portion of the second-conductivity-type cladding layer and a contact layer formed on the second-conductivity-type cladding layer. A first-conductivity-type current blocking layer is formed on both side walls of each of the ridge waveguides and on a portion around each of the ridge waveguides, and a leakage preventing layer is formed on the current blocking layer.

Abstract: In a monolithic dual-laser semiconductor laser device capable of high power output, a window structure for each of laser elements is formed through a common step, thereby improving the device reliability. The semiconductor laser device has an infrared laser element 110 and a red laser element 120 monolithically integrated on an n-type semiconductor substrate 101. Each of the infrared and red laser elements 110 and 120 has a ridged waveguide and a window structure formed by Zn diffusion at each resonator facet. The infrared and red laser elements 110 and 120 include p-type contact layers 109 and 119 on the ridges of the respective waveguides. The p-type contact layer 109 is thinner than the p-type contact layer 119.

Abstract: A tuneable laser assembly includes a substrate having formed thereon a plurality of tuneable lasers, waveguides, an optical coupler and an optical amplifier. The lasers have active sections and distributed Bragg reflector (DBR) tuning sections and are characterised by respective emission wavelengths and tuning ranges such that the laser assembly can be tuned over a quasi-continuous predetermined wavelength range. The DBR tuning sections have a length in the range of about 150-200 um, are of the same optical waveguide of the waveguides, a grating strength (KL) less than about 0,5 and a high reflective (HR) coated back facet enhancing the external quantum efficiency from each said tuning sections. The active sections have a length in the range of about 250-300 um comprised of a high-gain/low-loss multi quantum well (MQW) material. The lasers have a total DBR array length of about 500 um.

Abstract: A semiconductor laser apparatus includes multiple light emitting points, and a simple ridge stripe structure for each of the light emitting points. At least one of the light emitting points is disposed at a location that is 0% to 15% of the width of a substrate of the apparatus from the center, in the width direction, of the substrate.

Abstract: A light source module for use in display systems is provided herein. According to one exemplary embodiment, the light source module includes a plurality of coherent light sources, and a diffraction grating in optical communication with the coherent light source, the diffraction grating being configured to provide feedback to the coherent light source to produce a plurality of spectra over a broad spectrum.

Abstract: In one aspect of the present invention, a multiple wavelengths semiconductor laser device may include a supporting member, a first semiconductor laser element provided on a first substrate, mounted on the supporting member as face up, and configured to emit a first wavelength laser, and a second semiconductor laser element provided on a second substrate which has lower heat conductivity ratio than the first substrate, mounted on the supporting member as face down, and configured to emit a second wavelength laser toward in substantially a same direction as the first wavelength laser, and in another aspect of the invention, a multiple wavelengths semiconductor laser device may include a supporting member, a first semiconductor laser element provided on a first substrate, mounted on the supporting member as face up, and configured to emit a first wavelength laser, a second semiconductor laser element provided on a second substrate which has lower heat conductivity ratio than the first substrate, mounted on the s

Abstract: A tunable laser according to the present invention includes a plurality of Fabry-Perot semiconductor lasers comprising a plurality of semiconductor gain medium compositions disposed on a common sub-carrier with means for thermal tuning, and coupled to a sample. In a preferred embodiment, the lasers are coupled to a common multi-mode optical fiber, and an output radiation from the multi-mode fiber is tunable by switching the drive current amongst the lasers, and by thermal tuning of each laser in the array. In one preferred embodiment of this invention the plurality of Fabry-Perot semiconductor lasers are arranged around the perimeter of a cylindrical submount with a substantially circular cross-section. In another preferred embodiment a linear array of Fabry-Perot edge-emitting lasers is directly coupled to a multi-mode fiber. In still another preferred embodiment, an array of Fabry-Perot lasers is coupled to a fiber bundle.

Abstract: A laser diode apparatus (2) having a plurality of active regions (4a . . . 4n) which are arranged side by side and are designed for radiation production when the laser diode apparatus is in operation. A lateral dimension (ba . . . bn) of the active regions is varied in the lateral direction, and/or the distance (Da . . . D1) between adjacent active regions is varied in the lateral direction. Furthermore, a laser arrangement (1) is specified, having a laser diode apparatus which is arranged on a mount (6) with the mount being matched to the laser diode apparatus. Furthermore, a laser which is optically pumped by means of the laser diode apparatus or the laser arrangement is specified.

Abstract: In a semiconductor laser device, a plurality of light-emitting elements emitting light with different wavelengths are integrated on a substrate. Each of the light-emitting elements includes, on the substrate, an active layer and cladding layers respectively provided on top and bottom of the active layer. One of the cladding layers provided on top of the active layer is an upper cladding layer having a mesa ridge portion. An etching stopper layer for forming the ridge portion is interposed between the ridge portion and the other portion of the upper cladding layer. The thickness of the etching stopper layer varies among the light-emitting elements.

Abstract: A laser light source (10) of the present invention is provided with plural semiconductor lasers (1), and a waveguide (3) in which light beams emitted from the respective semiconductor lasers (1) propagate, and the plural semiconductor lasers are disposed at an upper end of an incident end face (31) of the waveguide so that the light beams (4) emitted from the respective semiconductor lasers enter the waveguide from the end face (31) of the waveguide and are emitted from another end face (32) of the waveguide. Thereby, it is possible to realize a high-power and compact laser light source which is able to output a light beam having a uniform light intensity distribution.

Abstract: A method for forming a modified semiconductor having a number of band gaps involves providing a semiconductor having a surface and a quantum region which emits photons in response to electrical or optical stimulation, the quantum region having an original band gap and being disposed under the surface and applying a number of layers of a number of materials to a number of selected regions of the surface, the materials being adapted to cause, upon thermal annealing, a number of different degrees of intermixing in a number of portions of the quantum region disposed immediately below each of the selected regions of the surface. The layers of materials can be applied in a dot or line pattern, or both, to increase the plurality of band gap tuning. The method includes thermally annealing the layers to the surface.

Abstract: In one aspect, a vertical cavity surface emitting laser (VCSEL) is operable to generate single-mode laser light at an operative wavelength. The VCSEL includes a light-emitting surface and a monolithic longitudinal stack structure. The longitudinal stack structure includes a first mirror, a second mirror, and a cavity region. The cavity region is disposed between the first mirror and the second mirror and includes an active light generation region and a cavity extension region. The longitudinal stack structure further includes an ion-implanted current confinement region. A VCSEL array incorporating the above described VCSEL and a method of making the above-described VCSEL also are described.

Abstract: This invention is to provide a semiconductor laser device with a small interval between light emitting points of laser lights and a method of manufacturing the same. A first light emitting element 1a having a semiconductor substrate 12a and a laser oscillation section 10a, and a second light emitting element 2a having a laser oscillation section 4a, are brought together with a ridged waveguide 8 of the laser oscillation section 10a facing the ridged waveguide 5 of the laser oscillation section 4a, and then bonded together by virtue of SOGs 3a having a small thickness. A conductive wiring layer Qa1 electrically connected with an ohmic electrode layer 9a on the ridged waveguide 8a, and a wiring layer Qa2 electrically connected with an ohmic electrode layer 6a on the ridged waveguide 5a, are arranged to extend until the insulating layer 11a on the semiconductor substrate 12a.

Abstract: A projection and a raised portion are formed on an upper surface of a blue-violet semiconductor laser device. A projection and a raised portion are formed on a lower surface of a red semiconductor laser device. The height of the projection is smaller than the height of the raised portion, and the height of the projection is smaller than the height of the raised portion. The blue-violet semiconductor laser device and the red semiconductor laser device are joined to each other such that the projections are opposed to each other.

Abstract: A semiconductor laser device in which a red semiconductor laser device and an infrared semiconductor laser device are located on a single substrate, and an end-face window structure is formed simultaneously. The hydrogen concentration (1.5e18 cm?3) of a fourth clad layer (110) of the infrared semiconductor laser device is higher than the hydrogen concentration (1e18 cm?3) of a second clad layer (105) of the red semiconductor laser device which is a first semiconductor laser device, whereby an active layer of the infrared semiconductor laser device can be sufficiently disordered in the semiconductor laser device.

Abstract: A semiconductor laser array is described. The semiconductor laser array may include a plurality of semiconductor laser elements including a first laser element and a second laser element. The first laser element may be configured to emit a shorter wavelength laser than the second laser element. The emission portion of the first laser element provided substantially on a center line of a substrate.

Abstract: A semiconductor laser device includes: a first light emitting device, the first light emitting device including a first first-conductive-type cladding layer, a first active layer having a first window region in the vicinity of a light emitting edge surface and a first second-conductive-type cladding layer stacked in this order on a substrate; and a second light emitting device, the second light emitting device including a second first-conductive-type cladding layer, a second active layer having a second window region in the vicinity of a light emitting edge surface and a second second-conductive-type cladding layer stacked in this order on the substrate. In the semiconductor laser device, respective lattice constants of the first second-conductive-type and second second-conductive-type cladding layers are adjusted to compensate for a difference in diffusion rate of an impurity between the first window region in the first active layer and the second window region in the second active layer.

Abstract: A plurality of vertical-cavity surface-emitting laser devices each having a different lasing wavelength are arrayed by a simple structure and a manufacturing process without increasing device resistance. Each vertical-cavity surface-emitting laser device comprises a layered structure including an active layer and a current confinement layer. The area of current confinement portion in the laminate structures is set corresponding to a wavelength of laser light emitted from each vertical-cavity surface-emitting laser device. Thereby, the plurality of vertical-cavity surface-emitting laser devices emits laser light with different lasing wavelengths.

Abstract: A semiconductor laser-based spectrometer according to the present invention includes a plurality of semiconductor lasers comprising a plurality of semiconductor gain medium compositions directly coupled to a large-core multi-mode fiber with no intervening optics. An output radiation from the multi-mode fiber is tunable by switching the drive current amongst the lasers, and by thermal tuning of each laser in the array. In combination with presentation to a sample, and means for detection of a diffuse reflectance or transmittance, this assembly functions as a compact, high signal to noise ratio, fast measurement spectrometer. In one preferred embodiment of this invention the plurality of semiconductor lasers consists of Fabry-Perot edge-emitting lasers arranged around the perimeter of a cylindrical submount with a substantially circular cross-section. In another preferred embodiment a linear array of Fabry-Perot edge-emitting lasers is directly coupled to a multi-mode fiber.

Abstract: A multi-beam semiconductor laser device capable of emitting respective laser beams with uniform optical output levels and enabling easy alignment is provided. This multi-beam semiconductor laser device (40) is a GaN base multi-beam semiconductor laser device provided with four laser stripes (42A, 42B, 42C and 42D) which are capable of emitting laser beams with the same wavelength. The respective laser oscillating regions (42A to 42D) are provided with a p-type common electrode (48) on a mesa structure (46) which is formed on a sapphire substrate (44), and have active regions (50A, 50B, 50C and 50D) respectively. Two n-type electrodes (52A and 52B) are provided on an n-type GaN contact layer (54) and located as common electrodes opposite to the p-type common electrode (48) on both sides of the mesa structure (46). The distance A between the laser stripe (42A) and the laser stripe (42D) is no larger than 100 ?m.

Abstract: A semiconductor laser device capable of providing high output power operation is provided which has a structure in which high output power and kink suppression can be simultaneously attained as well as these characteristics can be realized by a short chip length. In a waveguide structure of an MMI laser diode, a taper waveguide is intentionally inserted between a single mode waveguide and a multimode waveguide, and further, a single mode waveguide is used as a passive waveguide. These individual units or combination thereof can solve the above-described problems.

Abstract: Apparatus and methods for altering one or more spectral, spatial, or temporal characteristics of a light-emitting device are disclosed. Generally, such apparatus may include a volume Bragg grating (VBG) element that receives input light generated by a light-emitting device, conditions one or more characteristics of the input light, and causes the light-emitting device to generate light having the one or more characteristics of the conditioned light.

Abstract: A blue-violet emission point, an infrared emission point, and a red emission point in a semiconductor laser apparatus are arranged so as to be arranged in this order on a substantially straight line along a first direction. A blue-violet laser beam emitted from the blue-violet emission point and a red laser beam emitted from the red emission point are incident on an optical disk by an optical system comprising a polarizing beam splitter, a collimator lens, a beam expander, a ?/4 plate, an objective lens, a cylindrical lens, and an optical disk, is returned from the optical disk, and is introduced into an photodetector. The infrared laser beam emitted from the infrared emission point is incident on the optical disk by the optical system, is returned from the optical disk, and is introduced into the photodetector.

Abstract: A semiconductor laser device includes a substrate which is made of, e.g., silicon and which has in its principal surface first and second recessed portions formed at a distance from each other. Disposed in the first recessed portion is a first semiconductor laser chip in the form of a function block, which emits an infrared laser beam. Disposed in the second recessed portion is a second semiconductor laser chip in the form of a function block, which emits a red laser beam.

Abstract: A semiconductor laser device includes a first semiconductor laser element for emitting a first laser light having a first oscillation wavelength of ?1 and a second semiconductor laser element for emitting a second laser light having a second oscillation wavelength of ?2 (wherein ?2??1), which are formed on a single substrate. A first dielectric film which has a refractive index of n1 with respect to a wavelength ? between the first oscillation wavelength ?1 and the second oscillation wavelength ?2 and has a film thickness of approximately ?/(8n1) is formed at light emitting facets in the first semiconductor laser element and the second semiconductor laser element, from which the laser lights are emitted, and a second dielectric film having a refractive index of n2 and a film thickness of ?/(8n2) are formed on the first dielectric film.

Abstract: A plurality of vertical-cavity surface-emitting laser devices each having a different lasing wavelength are arrayed by a simple structure and a manufacturing process without increasing device resistance. Each vertical-cavity surface-emitting laser device comprises a layered structure including an active layer and a current confinement layer. The area of current confinement portion in the laminate structures is set corresponding to a wavelength of laser light emitted from each vertical-cavity surface-emitting laser device. Thereby, the plurality of vertical-cavity surface-emitting laser devices emits laser light with different lasing wavelengths.

Abstract: An improved semiconductor laser device is provided which has a small distance between laser light emitting spots. Such laser device comprises i) a first light emitting element including a laser oscillation section provided with a ridge waveguide and formed by forming a group-III nitride semiconductor film on a substrate, an insulating layer and an ohmic electrode layer, ii) a second light emitting element including a laser oscillation section provided with a waveguide and formed by forming III–V compound semiconductor film, an insulating layer and an ohmic electrode layer. By virtue of the adhesive metal layer interposed between the two ohmic electrode layers, the two laser oscillation sections are combined together, thereby forming the improved semiconductor laser device which has a small distance between laser light emitting spots of the two laser oscillation sections.

Abstract: A wavelength division multiplexing system based on arrays of wavelength tunable lasers and wavelength tunable resonant photodetectors is disclosed. The system allows self-adjusting of the resonance wavelength of the wavelength tunable photodetectors to the wavelengths of the laser light emitted by the lasers. No precise wavelength stabilization of the lasers is required.

Abstract: Lasers, such as in laser structures, can include two or more semiconductor structures that are substantially identical or that include the same semiconductor material and have substantially the same geometry, such as in closely spaced dual-spot two-beam or quad-spot four-beam lasers. The lasers can also include differently structured current flow or contact structures or different wavelength control structures. For example, current flow or contact structures can be differently structured to prevent or otherwise affect phase locking, such as by causing different threshold currents and different operating temperatures.

Abstract: A monolithic multiple-wavelength laser device includes a laser section of a first wavelength and a laser section of a second wavelength formed on a single GaAs substrate, wherein the laser section f the first wavelength includes a real guide structure, and the laser section of the second wavelength includes a loss guide structure. In such a multiple-wavelength laser device, loss in wave guiding can be reduced and operating current can be decreased, compared to a conventional device, when the first wavelength is within a wavelength band of about 780 nm and the second wavelength is within a wavelength band of about 650 nm, since the laser section of the first wavelength has the real guide structure.

Abstract: A semiconductor laser device comprises: a substrate having a top surface divided into a first region and a second region; a high-output LD including a first conductivity-type clad layer, an active layer, and a second conductivity-type clad layer including an upper portion having a first ridge structure, sequentially formed on the first region of the substrate; and a low-output LD including a first conductivity-type clad layer, an active layer, and a second conductivity-type clad layer including an upper portion having a second ridge structure, sequentially formed on the second region of the substrate, wherein the first and second ridge structures are formed in such a manner that they are extended to both ends opposed to each other, the first ridge structure is bent at two or more bending positions, and the second ridge structure is rectilinear.

Abstract: A method for manufacturing a vertical cavity surface emitting laser formed by laminating a plurality of layers on a substrate, includes coupling two layers of the plurality of layers by joining at room temperature or joining while heating.

Abstract: A widely wavelength-tunable laser source is provided using stacked tunable diode laser arrays which have different working wavelengths. Top surfaces of the laser arrays are disposed opposite and proximate. A coupling element employs an actuator to couple a beam from the arrays to an output waveguide. The laser source combines wavelength-tuning ranges of the arrays. The laser source also provides a backup scheme when the arrays have the same structure.

Abstract: The specification discloses a resonant cavity device array for wavelength division multiplexing and the method for fabricating it. The structure of the resonant cavity device is selectively formed with an oxide structure, which contains more than one AlxGa1-xAs oxide tuning layer. After the oxidation of AlGaAs, AlGaO is formed to change the refractive index and the thickness, thereby changing and controlling the wavelength of the resonant cavity device. The wavelength variant of each resonant cavity device is determined by the number of layers, thicknesses and compositions of the AlxGa1-xAs oxide tuning layer contained in the selective oxide structure.

Abstract: Disclosed herein is a method for producing a multi-wavelength semiconductor laser device. The method comprises the steps of: forming a nitride epitaxial layer on a substrate for growth of a nitride single crystal; separating the nitride epitaxial layer from the substrate; attaching the separated nitride epitaxial layer to a first conductivity-type substrate; selectively removing the nitride semiconductor epitaxial layer to expose a portion of the first conductivity-type substrate and to form a first semiconductor laser structure; and sequentially forming second and third semiconductor laser structures on the exposed portion of the first conductivity-type substrate.

Abstract: Disclosed herein is a method for producing a multi-wavelength semiconductor laser device. The method comprises the steps of: forming first and second nitride epitaxial layers in parallel on a substrate for growth of a nitride single crystal; separating the first and second nitride epitaxial layers from the substrate; attaching the separated first and second nitride epitaxial layers to a first conductivity-type substrate; selectively removing the first and second nitride semiconductor epitaxial layers to expose a portion of the first conductivity-type substrate and to form first and second semiconductor laser structures, respectively; and forming a third semiconductor laser structure on the exposed portion of the first conductivity-type substrate.

Abstract: A monolithically integrated dual-wavelength laser comprises at least three coupled Fabry-Perot cavities in tandem, each separated by a vertically etched air gap of a size that is substantially equal to an odd-integer multiple of quarter-wavelength. The first two cavities are of substantially comparable lengths and are actively pumped to provide gains to the combined cavity laser, and to produce a series of double-peaked lasing modes. The other cavity has a substantially smaller length and acts as an optical filter to select one of the doublets of the combined cavity as the lasing modes. The beating between the two modes of the dual-wavelength laser at a photodetector produces a microwave carrier signal whose frequency can be tuned by adjusting the balance of the injected currents between the two active cavities.

Abstract: Improving the lifetime of an integrated semiconductor laser diode module into which a GaN semiconductor laser diode and a GaP semiconductor laser diode are integrated, and the lasing properties of the laser diodes. Prior to a joining step of an LD 1 wafer that is made of a nitride semiconductor structure formed on a GaN substrate and an LD 2 wafer that is made of an aluminum gallium indium phosphide semiconductor structure, a facet of a resonator of the nitride semiconductor structure is formed by etching A facet of a resonator of the aluminum gallium indium phosphide semiconductor structure is formed, after the joining step, by cleaving. The wafers are joined so that the facets of the resonators of the nitride semiconductor structure and aluminum gallium indium phosphide semiconductor structure are out of alignment in a lengthwise direction of the resonators.