Abstract: A VCSEL device includes a polyimide having a larger thickness (d1) on the surface of a semiconductor layer structure in a peripheral area 54, which is separated from a mesapost by an annular groove 52. The top surface of the central mesapost 30 is located at a lower position compared to the top surface of the peripheral area 54. A structure is obtained wherein the mesapost is not contacted by a jig or probe during handling the device in the test or assembly thereof.

Abstract: Diode lasers comprise a substrate and a number of material layers disposed thereon that include a P-type material layer, and an N-type material layer. A gain layer and diffraction grating feedback layer can be also be included in the material layers. The material layers are formed by epitaxial deposition, during which process a wall surface common to the material layers is also formed. This wall surface forms an internally reflective wall surface within the material layers that is oriented to reflect a laser beam internally within the diode laser construction towards a top or bottom surface of the diode laser for emission therefrom. In an preferred embodiment, the internally reflective wall surface is oriented at a 45 degree angle, and the laser beam is reflected by the wall surface to emit the laser beam from the diode laser at a 90 degree angle relative to the top or bottom surface.

Abstract: Vertical cavity surface emitting lasers (VCSELs) and methods of making the same are described. The VCSELs include reliability-enhancing layers that perform specific functions at one or more critical locations within a VCSEL structure to reduce or prevent defect formation and migration that otherwise might degrade VCSEL performance, for example, by increasing optical absorption in the mirror stacks or by degrading the electro-optic properties of the active region. In particular, the reliability-enhancing layers are configured to perform one or more of the following functions within the VCSEL structure: gettering (i.e., removing defects or impurities from critical regions), strain balancing (i.e., compensating the lattice mismatch in the structure to minimize strain), and defect suppression (i.e., creating alloys that reduce the formation of defects during growth or post-growth activities).

Abstract: A volume Bragg grating (VBG) has a narrow wavelength. The wavelength is changed by changing an angle of the VBG or a temperature of the VBG. Thus, the present invention has a narrow wavelength, a bright laser, a simple system and an adjustable reflection for a wide application to laser systems.

Abstract: Structures including dielectric diffraction gratings. In some embodiments, laser devices include diffraction gratings defined by openings formed in a dielectric material.

Abstract: A wavelength converting laser device includes a laser diode producing laser light and including an optical resonator having a pair of facing reflectors, including a reflecting surface having a shape reducing loss in the optical resonator, with regard to a specific horizontal transverse mode of laser light as compared to the loss in the optical resonator for other horizontal transverse modes, and a wavelength converter for converting the laser light into harmonic light.

Abstract: The present invention is directed to a method and system for providing a three-level current scheme to a semiconductor laser to control beam wavelength and laser temperature. A first current is received into a gain section of the semiconductor laser and at least one other current is received into a DBR and/or phase section of the semiconductor laser. This other current(s) is pulse-width modulated based upon a required temperature value. An output beam is generated by the semiconductor laser based upon the received first current and the received pulse-width modulated current(s).

Abstract: A surface emitting laser includes a lower Bragg reflector, a resonator and an upper Bragg reflector. The resonator is provided on top of the lower Bragg reflector and includes an active layer, a lower semiconductor layer and an upper semiconductor layer. The upper Bragg reflector is provided on top of the resonator, and includes a plurality of semiconductor layers. In this surface emitting laser, the uppermost layer among the plurality of semiconductor layers in the lower Bragg reflector forms an air gap, which is larger than the aperture of the first insulating layer, while the lowermost layer among the plurality of semiconductor layers in the upper Bragg reflector forms an air gap, which is larger than the aperture of the second insulating layer.

Abstract: A method and apparatus for spatial mode selection of planar waveguide and thin slab lasers in the laser's large cross section size direction. The planar laser has a small cross section size direction orthogonal to a major axis thereof and a large cross section size direction orthogonal to the small cross section size direction and to the major axis. A planar reflector is disposed at one end of the planar laser, the planar reflector having a reflecting surface which is arranged orthogonally to the major axis and parallel to both the small and large cross section size directions of the laser. A Bragg grating is disposed in the optical track of the laser, the Bragg grating having a grating vector which is arranged in the plane normal to said small cross section size direction and at the angle between 0° and 90° to said large cross section size direction for suppression of higher order optical modes in said large cross section size direction.

Abstract: A bottom-emitting nitride light-emitting device with enhanced light extraction efficiency is provided. The increased light output is provided by the reflector that redirects upward-going light towards the bottom output. A mesh contact area, in one form, spreads current across the entire carrier injection area without occupying the entire top surface of the device.

Abstract: Example embodiments may provide an increased efficiency laser chip and/or a vertical external cavity surface emitting laser (VECSEL) using the same. Example embodiment laser chips may include a substrate; a DBR (distributed Bragg reflector) layer on the substrate, an active layer on the DBR layer having multiple quantum wells excited by a pump beam to generate light, and/or an upper coating layer on the active layer by alternately stacking first and second layers each having different refractive indexes. Thicknesses of the first and second layers may be substantially equal to a quarter of a wavelength of light generated by the active layer.

Abstract: A semiconductor laser is disclosed with which a VCSEL can be constituted with a simplified configuration for optical transmission at a transmission rate higher than 10 Gbps. The semiconductor laser includes a resonator including a first active region able to emit light in response to current injection and a second active region able to emit light in response to external excitation light. Multilayer film reflecting mirrors sandwich the resonator from two opposite sides. The first active region and the second active region generate light at a wavelength the same as the resonance mode of the resonator.

Abstract: A phase-conjugating resonator that includes a semiconductor laser diode apparatus that comprises a phase-conjugating array of retro-reflecting hexagon apertured hexahedral shaped corner-cube prisms, an electrically and/or optically pumped gain-region, a distributed bragg reflecting mirror-stack, a gaussian mode providing hemispherical shaped laser-emission-output metalized mirror. Wherein, optical phase conjugation is used to neutralize the phase perturbating contribution of spontaneous-emission, acoustic phonons, quantum-noise, gain-saturation, diffraction, and other intracavity aberrations and distortions that typically destabilize any stimulated-emission made to undergo amplifying oscillation within the inventions phase-conjugating resonator. Resulting in stablized high-power laser-emission-output into a single low-order fundamental transverse cavity mode and reversal of intracavity chirp that provides for high-speed internal modulation capable of transmitting data at around 20-Gigabits/ps.

Abstract: The invention provides a semiconductor integrated circuit which allows a plurality of devices to be integrated compactly, that is, with high density; a signal transmitting device; an electro-optical device; and an electronic apparatus. A semiconductor integrated circuit includes tile-shaped microelements that are superimposed upon and adhered to the top surface of a substrate with an adhesive.

Abstract: A DBR structure in a VCSEL diode, a method of manufacturing the DBR structure, and a VCSEL diode are provided. The DBR structure in the VCSEL diode includes: an InAlGaAs layer having a predetermined refractive index and disposed on an InP substrate; a first InAlAs layer having a lower refractive index than the InAlGaAs layer and disposed on the InAlGaAs layer; an InP layer having a lower refractive index than the InAlGaAs layer and disposed on the first InAlAs layer; and a second InAlAs layer having a lower refractive index than the InAlGaAs layer and disposed on the InP layer. Thus, the DBR structure can reduce optical loss due to type-II band line-up at a junction between the InAlGaAs layer and the InP layer, and thus improve device characteristics.

Abstract: A tunable laser includes an optical waveguide alternately including a gain waveguide portion and a wavelength controlling waveguide portion, and a diffraction grating. The diffraction grating includes a gain diffraction grating and a wavelength controlling diffraction grating. A wavelength controlling region is configured such that the wavelength controlling waveguide portion and the wavelength controlling diffraction grating are included therein. A gain region is configured such that the gain waveguide portion and the gain diffraction grating are included therein. The Bragg wavelength of the wavelength controlling region is longer than that of the gain region in a state in which current injection or voltage application is not performed for the wavelength controlling waveguide portion.

Abstract: Arrays of vertical extended cavity surface emitting lasers (VECSELs) are disclosed. The functionality of two or more conventional optical components are combined into an optical unit to reduce the number of components that must be aligned during packaging. A dichroic beamsplitter selectively couples frequency doubled light out of the cavity. In one implementation the dichroic beamsplitter includes at least one prism.

Abstract: A vertical-cavity surface-emitting laser including an annular upper electrode disposed on a laser light exit surface, wherein an upper electrode aperture is formed therein and a light blocking layer is positioned at the center of the aperture formed in the upper electrode. The light blocking layer partially blocks laser light emitted from the vertical-cavity surface-emitting laser, providing a difference in reflectance in a transverse direction of the vertical-cavity surface-emitting laser, facilitating single mode oscillation.

Abstract: Dual-wavelength operation is easily achieved by biasing the gain section. Multiple gratings spaced apart from each other are separated from an output aperture by a gain section. A relatively low coupling coefficient, ?, in the front grating reduces the added cavity loss for the back grating mode. Therefore, the back grating mode reaches threshold easily. The space section lowers the current induced thermal interaction between the two uniform grating sections, significantly reducing the inadvertent wavelength drift. As a result, a tunable mode pair separations (??) as small as 0.3 nm and as large as 6.9 nm can be achieved.

Abstract: A light emitting device includes a light emitting portion provided on a reference plane to supply light, and an optical portion provided on the output side of the light emitting portion to transmit light from the light emitting portion. In the device, the optical portion is formed so that its refractive index periodically changes in a two-dimensional direction approximately parallel to the reference plane, and the optical portion can be formed separately from the light emitting portion.

Abstract: The present invention is a tunable semiconductor laser for swept source optical coherence tomography, comprising a semiconductor substrate; a waveguide on top of said substrate with multiple sections of different band gap engineered multiple quantum wells (MQWs); a multiple of distributed feedback (DFB) gratings corresponding to each said band gap engineered MWQs, each DFB having a different Bragg grating period; and anti-reflection (AR) coating deposited on at least the laser emission facet of the laser to suppress the resonance of Fabry-Perot cavity modes. Each DFB MQWs section can be activated and tuned to lase across a fraction of the overall bandwidth as is achievable for a single DFB laser and all sections can be sequentially activated and tuned so as to collectively cover a broad bandwidth, or simultaneously activated and tuned to enable a tunable multi-wavelength laser.

Abstract: The present invention is to provide a vertical cavity surface emitting laser diode (VCSEL) that has a functional distributed Bragg reflector (DBR) comprised of less number of pairs of reflective layers. The VCSEL of the invention include a lower DBR, an upper DBR and an active layer arranged between the upper and lower DBRs. The upper DBR is comprised of a plurality of pairs including GaAs layers and aluminum oxide layers, thus the GaAs layers and the aluminum oxide layers are alternately stacked to each other. Since the refractive index of the aluminum oxide (Al2O3) is 1.67 at 1.3 ?m and that of the GaAs is 3.51, the difference of these refractive index becomes 1.85, which is far greater than the combination of the AlAs and the GaAs, thereby decreasing the number of pairs for the DBR.

Abstract: A PLC-based wavelength-tunable WDM-PON system with an optical wavelength alignment function, the WDM-PON system comprises: a PLC platform formed on a silicon substrate; a semiconductor chip comprising an active region generating light and a passive region located in front of the active region for vertically coupling the light generated in the active region; a planar lightwave circuit (PLC) waveguide; one portion of a PLC platform where the semiconductor chip is surface mounted; waveguide Bragg grating (WBG) formed at a predetermined location of the PLC waveguide; a directional coupler transferring an optical power by permitting the passive region to approach the PLC waveguide; a heater terminal, which is formed on the WBG; and a V-groove for attaching an optical fiber to another end of the PLC waveguide. Accordingly, a WDM-PON system having a function of realizing a cost-effective optical wavelength alignment can be provided.

Abstract: A vertical extended cavity surface emitting laser (VECSEL) includes intra-cavity frequency doubling. Conventional frequency control elements, such as etalons, are replaced with thin film interference filters or volume Bragg gratings.

Abstract: A surface emitting semiconductor device comprises an active layer, a p-type III-V compound semiconductor layer, an n-type III-V compound semiconductor layer, and a burying layer. The active layer includes a primary surface, the primary surface having first and second areas. The p-type III-V compound semiconductor layer is provided on the first and second areas of the primary surface of the active layer. The n-type III-V compound semiconductor layer is provided on the second area of the primary surface of the active layer. The n-type III-V compound semiconductor is provided on the p-type III-V compound semiconductor layer. The n-type III-V compound semiconductor and the p-type III-V compound semiconductor layer form a tunnel junction. The n-type III-V compound semiconductor layer contains tellurium as an n-type dopant. The burying layer is made of III-V compound semiconductor. The n-type III-V compound semiconductor layer is covered with the burying layer.

Abstract: A surface-emitting type semiconductor laser includes: a lower mirror; an active layer formed above the lower mirror; and an upper mirror formed above the active layer, wherein each of the lower mirror and the upper mirror is composed of a multilayer mirror in which a plurality of unit multilayer films are laminated, each of the unit multilayer films includes a pair of a lower refractive index layer and a higher refractive index layer laminated in a thickness direction, each of the unit multilayer films satisfies a formula (1) below, and the active layer satisfies a formula (2) below, dD<?/2nD ??(1) dA>m?/2nA ??(2) where ? is a design wavelength of the surface-emitting type semiconductor laser, in is a positive integer, dD is a thickness of the unit multilayer film, nD is a mean refractive index of the unit multilayer film, dA is a thickness of the active layer, and nA is a mean refractive index of the active layer.

Abstract: An improved grating-outcoupled surface-emitting semiconductor laser architecture is provided. A second-order grating is placed between two distributed Bragg reflector gratings. The period of the second order grating is positively or negatively detuned from the distributed Bragg reflector selected optical wavelength at which the laser operates. Detuning of the second-order grating towards shorter or longer wavelengths allows kink-free, linear LI curves light output versus forward current) for grating-outcoupled surface-emitting lasers. Due to the detuning of the outcoupler grating, the outcoupled radiation emits two beams that deviate slightly from the normal axis. A design point may then be chosen where the power outcoupled by symmetric and antisymmetric modes cross and where the outcoupled power is independent of the phase variation.

Abstract: A device contains at least one wavelength-tunable multilayer interference reflector controlled by an applied voltage and at least one cavity. The stopband edge wavelength of the wavelength-tunable multilayer interference reflector is preferably electrooptically tuned using the quantum confined Stark effect in the vicinity of the cavity mode (or a composite cavity mode), resulting in a modulated transmittance of the multilayer interference reflector. A light-emitting medium is preferably introduced in the cavity or in one of the cavities permitting the optoelectronic device to work as an intensity-modulated light-emitting diode or diode laser by applying an injection current. The device preferably contains at least three electric contacts to apply forward or reverse bias and may operate as a vertical cavity surface emitting light-emitter or modulator or as an edge-emitting light emitter or modulator.

Abstract: The object of the invention is to reduce the deterioration of crystallinity in the vicinity of an active layer when C, which is a p-type dopant, is doped and to suppress the diffusion of Zn, which is a p-type dopant, into an undoped active layer, thus to realize a sharp doping profile. When a Zn-doped InGaAlAs layer having favorable crystallinity is provided between a C-doped InGaAlAs upper-side guiding layer and an undoped active layer, the influence of the C-doped InGaAlAs layer whose crystallinity is lowered can be reduced in the vicinity of the active layer. Further, the Zn diffusion from a Zn-doped InP cladding layer can be suppressed by the C-doped InGaAlAs layer.

Abstract: A distributed feedback laser diode comprises a phase-shifting portion in diffraction gratings. The magnitude of a phase shift in the phase-shifting portion is 8 ?/40 to 9 ?/40, ? representing twice the distance between the diffraction gratings. A main mode stands on a lower wavelength side than the center of a stop band when an injected current is of a level of a threshold current, whereas the main mode is shifted to the center of the stop band and a sub mode is suppressed from growing when the injected current is of a level of an operating current.

Abstract: A semiconductor laser according to the present invention comprises: a substrate; an n-cladding layer disposed on the substrate; an active layer disposed on the n-cladding layer; a p-cladding layer disposed on the active layer and forming a waveguide ridge; and a diffraction grating layer disposed between the active layer and the n-cladding layer or the p-cladding layer and including a phase shift structure in a part of the diffraction grating layer in an optical waveguide direction. The width of the p-cladding layer is increased in a portion corresponding to the phase shift structure of the diffraction grating layer.

Abstract: A vertical cavity surface emitting laser (VCSEL) structure includes a bottom distributed Bragg reflector (DBR) arranged over a substrate; a metal layer interposed between the bottom DBR and the substrate, wherein the metal layer and bottom DBR form a composite mirror structure. A patterned dielectric layer may be interposed between the metal layer and the bottom DBR to reduce a deleterious chemical reaction between the metal layer and the bottom DBR. The metal layer directly contacts a portion of the bottom DBR to enhance the electrical and thermal conductivity of the VCSEL structure.

Abstract: A radiation-emitting semiconductor component, having a semiconductor layer sequence (1) with an active zone (2) provided for radiation generation and a first mirror arranged downstream of the active zone. The first mirror comprises a metal layer (4) and an intermediate layer (3) made of a radiation-transmissive and electrically conductive material, said intermediate layer being arranged on that side of the metal layer (4) which faces the active zone. The radiation-emitting semiconductor component is provided for operation with an optical resonator and for generating predominantly incoherent radiation as an RCLED or the radiation-emitting semiconductor component being provided for operation with an external optical resonator and for generating predominantly coherent radiation as a VECSEL.

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: Embodiments of systems and methods are provided for a tunable laser device. The tunable laser device may include a diffraction grating connected to a pivot arm that pivots the diffraction grating about a pivot point to tune the laser device. In pivoting the diffraction grating about the pivot point, both the wavelength to which the diffraction grating is tuned and the length of the optical cavity may be changed. The length of the pivot arm may be selected to reduce the number of mode hops of the tunable laser device when tuning the laser device over its tuning range.

Abstract: A semiconductor material vertical cavity surface emitting laser for emitting narrow linewidth light comprising a compound semiconductor material substrate and pairs of semiconductor material layers in a first mirror structure on the substrate of a first conductivity type each differing from that other in at least one constituent concentration and each first mirror pair separated from that one remaining by a first mirror spacer layer with a graded constituent concentration. An active region on the first mirror structure has plural quantum well structures separated by at least one active region spacer layer and there is a second mirror structure on the active region similar to the first but of a second conductivity type. A pair of electrical interconnections is separated by said substrate, said first mirror structure, said active region and said second mirror structure.

Abstract: Provided are a laser apparatus into which a large current can be injected and a production method which enables easy production of the apparatus. A laser apparatus includes a light-emitting region on a substrate, and a periodic refractive index structure containing an i-type material provided at a periphery of the light-emitting region. Another laser apparatus includes a light-emitting region between a first electrode and a second electrode on a substrate, wherein at least one of the first and the second electrodes includes a periodic refractive index structure.

Abstract: A semiconductor optical device includes a GaAs substrate having a surface with periodic projections and recesses for a diffraction grating; a III-V compound semiconductor layer provided on the surface of the GaAs substrate; and an active layer which is made of III-V compound semiconductor containing nitrogen and arsenic as constituent elements, the active layer being provided on the III-V compound semiconductor layer.

Abstract: A vertical-cavity surface emitting laser includes a substrate and a first mirror that is grown on the substrate, a second mirror grown on the first mirror for resonating the first mirror and light, an active layer between the first mirror and the second mirror for generating and amplifying the light, an upper electrode grown on the active layer and a lower electrode formed on the first mirror for supplying current to the active layer, a planarizing polymer formed on the first mirror for burying the active layer and the second layer, and a first external terminal extending from the upper electrode in a vertical upward direction to be exposed to the top surface of the planarizing polymer and a second external terminal extending from the lower electrode to expose its one surface to the top surface of the planarizing polymer.

Abstract: A semiconductor laser has a structure in which the following layers are stacked on one another over an n-type substrate: a buffer layer, a diffraction grating layer, a diffraction grating burying layer, a light confining layer, a multiple quantum well active layer, a light confining layer, and a cladding layer. In this structure, the distance D between the center of the active layer and the interface between the n-type substrate and the buffer layer is set to a value longer than the 1/e2-beam spot radius a of the laser light.

Abstract: There are provided a bi-directional transceiver module and a method for driving the same. The bi-directional transceiver module includes a 1.3 ?m Distributed Bragg Reflection Laser Diode (DBR LD) including an active layer which performs light-emission in response to a light at 1.3 ?m and a DBR mirror formed near the active layer. The DBR mirror is formed to prevent an upstream signal emerging from the 1.3 ?m DBR LD from being deleted by a PD. A monitoring PD and a PD for detecting an optical signal are integrated and mounted behind the DBR mirror using a butt-joint method. The 1.3 ?m DBR LD, the monitoring PD, and the PD for detecting the optical signal are electrically isolated by insulated areas. To drive the bi-directional transceiver module, a forward bias (+) is applied to a p-electrode formed on the 1.3 ?m DBR LD, a backward bias (?) is applied to p-electrodes formed on the monitoring PD and the PD for detecting the optical signal, and a n-electrode as a common electrode is grounded.

Abstract: A semiconductor monolithic integrated optical transmitter including a plurality of active layers formed on a semiconductor substrate is disclosed, which comprises: a distributed feedback laser diode including a grating for reflecting light with a predetermined wavelength and a first active layer for oscillating received light from the grating; an electro-absorption modulator including a second active layer for receiving light from the first active layer, wherein the received light intensity is modulated through a change of absorbency in accordance with an applied voltage; an optical amplifier including a third active layer for amplifying received light from the second active layer; a first optical attenuator between the first active layer and the second active layer; and a second optical attenuator between the second active layer and the third active layer.

Abstract: A surface-emission laser diode includes a distributed Bragg reflector tuned to wavelength of 1.1 ?m or longer, wherein the distributed Bragg reflector includes an alternate repetition of a low-refractive index layer and a high-refractive index layer, with a heterospike buffer layer having an intermediate refractive index interposed therebetween with a thickness in the range of 5–50 nm.

Abstract: The present invention is to provide a DFB-LD with a larger coupling efficiency between the grating and the active layer. The DFB-LD of the invention provides an n-type InP substrate, an n-type InP buffer layer, an AlGaInAs layer, a intermediate layer made of a material belonging to a group III-V compound semiconductor and containing phosphorous, and an active layer. The InP substrate and the InP buffer layer form a periodic undulation of the grating. Because of the AlGaInAs layer just provided on the InP buffer layer, the AlGaInAs layer and the intermediate layer can be thinned to get a flat top surface, which enhances the coupling efficiency between the grating and the active layer.

Abstract: A grating-outcoupled microcavity disk resonator has whispering gallery modes existing in a nearly circular resonator. Light is outcoupled by providing a grating region in the plane of the grating-outcoupled microcavity disk resonator. The grating region provides an outcoupling or loss mechanism that symmetrically interacts with the clockwise and counterclockwise whispering gallery modes, thereby making the resonator capable of surface emission.

Abstract: A optical data processing apparatus included a light source, an optical system that concentrates light from the light source to an optical data storage medium, and a mechanism that scans the concentrated laser light on the optical data storage medium, the light source includes at least one Vertical-Cavity Surface-Emitting Laser (VCSEL) device that emits laser light, the at least one VCSEL device included an active region and a current-confined portion between first and second mirrors that form a vertical resonator structure, and an opening having a diameter equal to or larger than about 4 micrometers is formed in the current-confined portion for applying current.

Abstract: A Vertical External Cavity Surface Emitting Laser (VECSEL) system is provided. The VECSEL system includes a laser device including an active layer in which laser light is generated by pumping and a reflector reflecting the laser light generated in the active layer; an optical element that forms a cavity together with the reflector of the laser device and reduces a linewidth of laser light; and a SHG (Second Harmonic Generation) device that is disposed between the laser device and the optical element and doubles the frequency of laser light.

Abstract: Provided is a vertical cavity external surface emitting laser (VECSEL) apparatus in which incidence loss of a pumping beam can be reduced. The VECSEL apparatus includes: a laser chip including: an anti-reflection coating (ARC) layer to which a pumping beam is incident; a low Herpin Index distributed Bragg reflector (LHI-DBR) having a LHI stack structure; and a periodic gain layer that is formed on the LHI-DBR and generates laser light by being excited by the pumping beam; and an external cavity mirror that is installed outside the laser chip and faces the periodic gain layer and constitutes a laser cavity with the LHI-DBR.

Abstract: When a ratio R between a total angle ? of a widening angle in a median intensity of light of a light source (a GaN based semiconductor laser) and a total angle 2/? of a widening angle of light defining a numerical aperture NA of a collimator optical system (collimator lens) is defined as R=(sin?1NA)×2/?, the numerical aperture of the collimator optical system (collimator lens) is set so that 2.0?R?0.58. Thus, an image exposure device is provided that can suppress stray light of a light source that emits a large amount of stray light.

Abstract: Our wafer scale processing techniques produce chip-laser-diodes with a diffraction grating (78) that redirects output light out the top (88) and/or bottom surfaces. Generally, a diffraction grating (78) and integrated lens-grating (78) are used herein to couple light from the chip to an output fiber (74), and the lens-grating (78) is spaced from the diffraction grating (76). Preferably the diffraction grating (76) and integrated lens grating (78) are also used to couple light from the output fiber (74) back to the active region of the chip. The integrated lens-grating (78) can be in a coupling block (82). The use of a coupling block (82) can eliminate “facet-type damage”. A coupling block (82) is generally used herein to couple light from the chip to an output fiber (74), and preferably to couple feedback reflected from the fiber (74) back to the chip.