Abstract: The present invention relates to a lasing device for use in an optical module. The lasing device comprises a first reflector and a second reflector; a confinement layer adapted to confine current within a current-confining aperture; and an active layer between the first and second reflectors. The active layer comprises a main active region aligned with the current confining aperture and an auxiliary active region surrounding the main active region. The second reflector includes a first reflector region arranged on the current-confining aperture and a second reflector region surrounding the first reflector region. The second reflector region and the first reflector are configured to induce stimulated recombination in the auxiliary active region.

Abstract: Disclosed are semiconductor microtube lasers including a semiconductor multilayer heterostructure. The multilayer heterostructure includes a substantially cylindrical optically active structure capable of light emission when under the influence of an applied electromagnetic field and a substantially cylindrical distributed feedback grating structure configured to provide optical feedback for a selected wavelength of light from the optically active region and to produce lasing action from the microtube when under the influence of an applied electromagnetic field.

Abstract: A hybrid laser for generating radiation includes an optical passive material and an optical active material. The laser includes a first optical waveguide and optical laser components with reflectors in the optical passive material. The first optical waveguide is adapted for coupling out radiation from the hybrid laser. The laser also includes a second optical waveguide defined in the optical active material. The optical laser components include reflectors defining a cavity and furthermore are adapted for providing laser cavity confinement in the first optical waveguide and the second optical waveguide. The second optical waveguide thereby is positioned at least partly over the first optical waveguide so that an evanescent coupling interface is defined between the second optical waveguide and the first optical waveguide and the evanescent coupling interface is positioned within the laser cavity.

Abstract: Method for calibrating and tuning a part wise monotonically, continuously tunable semiconductor laser having a phase section and a first Bragg reflector section, through which sections a phase current and a first reflector current, respectively, are applied, which laser is not actively cooled, includes a) a calibration step, including obtaining at least two tuning lines along which tuning lines all combinations of phase and Bragg currents are stable operating points, identifying at least one reference stable operating point along a first one of the identified tuning lines at which operating point the laser emits light at a certain reference frequency, and storing at least one reference stable operating point; and b) a subsequent tuning step, during which the output frequency of the laser in relation to the reference frequency is controlled to a desired output frequency by translating the operating point of the laser along the first tuning line.

Abstract: The present invention provides a light source for light circuits on a silicon platform. A vertical laser cavity is formed by a gain region arranged between a first mirror structure and a second mirror structure, both acting as mirrors, by forming a grating region including an active material in a silicon layer in a semiconductor structure or wafer structure. A waveguide for receiving light from the region of the mirrors is formed within or to be connected to the region of the mirrors, and functions as an output coupler for the VCL. Thereby, vertical lasing modes are coupled to lateral in-plane modes of the in-plane waveguide formed in the silicon layer, and light can be provided to e.g. photonic circuits on a SOI or CMOS substrate in the silicon.

Abstract: There is provided a distributed Bragg's reflector (DBR) comprising a substrate and an unit distributed Bragg's reflector (DBR) layer, wherein a multi-layer is laminated on the substrate. The unit DBR layer is composed of a multi-layer laminated structure of unit digital-alloy multinary compound semiconductor layer/multinary compound semiconductor layer or unit digital-alloy multinary compound semiconductor layer/unit digital-alloy multinary compound semiconductor layer. The unit digital-alloy multinary compound semiconductor layer is composed of the multi-layer laminated structure of the first layer of multinary compound semiconductor and the second layer of a different multinary compound semiconductor on said first layer. The digital-alloy distributed Bragg's reflector of the present invention has a uniform quality on the substance area and the filter and reflector having uniformly high quality can be mass produced by using the reflector.

Abstract: An Echelle diffraction grating has a Littrow configuration. Each grating includes a resin layer made of light curing resin and having a thickness between 2 ?m and 10 ?m, and a reflective coating layer formed on the resin layer, having a thickness between 120 nm and 500 nm, and made of aluminum. An apex angle between a blazed surface and a counter surface is between 85° and 90°. A first blaze angle is an angle that maximizes diffraction efficiency of a set blazed order for incident light of a wavelength of 193.3 nm. A blaze angle has an initial value of a second blaze angle smaller than the first blaze angle. 0.25°?bd?ba?1.2° is satisfied where bd denotes the first blaze angle and ba denotes the second blaze angle.

Abstract: A laser diode with which high density crystal defect and surface roughness are able to be inhibited from being generated is provided. The laser diode includes a laminated body including an active layer and a current narrowing layer on a substrate. The substrate is an inclined substrate having an off-angle larger than 0 degrees in the direction of [1-100] from (0001) C plane.

Abstract: Provided are a dual mode semiconductor laser and a terahertz wave apparatus using the same. The dual mode semiconductor laser includes a distributed feedback laser structure section including a first diffraction grating on a substrate and a distributed Bragg reflector laser structure section including a second diffraction grating on the substrate. A first wavelength oscillated by the distributed feedback laser structure section and a second wavelength oscillated by the distributed Bragg reflector laser structure section are different from each other, and the distributed feedback laser structure section and the distributed Bragg reflector laser structure section share the same gain medium with each other.

Abstract: A method of fabrication of laser gain material and utilization of such media includes the steps of introducing a transitional metal, preferably Cr2+ thin film of controllable thickness on the ZnS crystal facets after crystal growth by means of pulse laser deposition or plasma sputtering, thermal annealing of the crystals for effective thermal diffusion of the dopant into the crystal volume with a temperature and exposition time providing the highest concentration of the dopant in the volume without degrading laser performance due to scattering and concentration quenching, and formation of a microchip laser either by means of direct deposition of mirrors on flat and parallel polished facets of a thin Cr:ZnS wafer or by relying on the internal reflectance of such facets. Multiple applications of the laser material are contemplated in the invention.

Abstract: High-power, phased-locked, laser arrays as disclosed herein utilize a system of optical elements that may be external to the laser oscillator array. Such an external optical system may achieve mutually coherent operation of all the emitters in a laser array, and coherent combination of the output of all the lasers in the array into a single beam. Such an “external gain harness” system may include: an optical lens/mirror system that mixes the output of all the emitters in the array; a holographic optical element that combines the output of all the lasers in the array, and an output coupler that selects a single path for the combined output and also selects a common operating frequency for all the coupled gain regions.

Abstract: An optical device includes a first substrate, having first and second surfaces, and a second substrate having a third surface. The first substrate includes: a laser unit, having an active layer and emitting light into the first substrate from the active layer; a reflecting mirror, having a plane obliquely intersecting an optical axis of light emitted from the laser unit, and being formed on the first surface so as to reflect the light toward the second surface; and a convex lens, being formed in a region on the second surface, the region including an optical axis of the light reflected by the reflecting mirror. The second substrate is provided with a grating coupler and an optical waveguide on the third surface, the optical waveguide having light incident on the grating coupler propagating therethrough.

Abstract: In a surface-emission laser diode, there is provided, between an active layer and a semiconductor layer that contains Al, Ga and As as major components, a semiconductor layer containing Al, In and P as major components such that the semiconductor layer containing Al, In and P as major components is provided adjacent to the semiconductor layer that contains Al, Ga and As as major components. Further, an interface between the semiconductor layer containing Al, Ga and As as major components and the semiconductor layer containing Al, In and P as major components is coincident to a location of a node of electric field strength distribution.

Abstract: A nitride semiconductor surface-emitting laser includes a two-dimensional photonic crystal layer having a resonant mode in an in-plane direction. The surface-emitting laser includes an active layer, the two-dimensional photonic crystal layer, a semiconductor layer, and an electrode in this order. The two-dimensional photonic crystal layer contains p-type conductive InxGa1-xN (0?x?1) as a high-refractive-index medium. The semiconductor layer contains p-type conductive InyGa1-yN (0?y?1). The thickness tPhC of the two-dimensional photonic crystal layer satisfies the relation of tPhC?(?/neff), wherein ? denotes the lasing wavelength, and neff denotes the effective refractive index of the resonant mode.

Abstract: A semiconductor laser includes a gain region; a distributed Bragg reflector (DBR) region including a diffraction grating; an end facet facing the DBR region with the gain region arranged therebetween; a first ring resonator including a first ring-like waveguide and a first optical coupler; a second ring resonator including a second ring-like waveguide and a second optical coupler; and an optical waveguide that is optically coupled to the end facet and extending in a predetermined optical-axis direction. The first and second ring resonators are optically coupled to the optical waveguide through the first and second optical couplers, respectively. Also, the DBR region, the gain region, and the end facet constitute a laser cavity. Further, the first ring resonator has a free spectral range different from a free spectral range of the second ring resonator.

Abstract: A semiconductor laser includes: a DBR (Distributed Bragg Reflector) region having a diffraction grating; a FP (Fabry-Perot) region having no diffraction grating; and an optical waveguide section placed between the DBR region and an outputting end surface. A length of the optical waveguide section is longer than a length of the DBR region in a resonator length direction.

Abstract: Two or more first reflectors are formed on a substrate. Each of the first reflectors reflects the light input to its input port and returns it there, while exhibiting a reflection spectrum featuring a peak at the target wavelength. A first optical coupler is formed on the substrate to divide the light output from an optical amplifier and output the divided lights to the input ports of the two or more first reflectors, as well as combining the reflected lights from the first reflector and re-inputting the combined light to the optical amplifier. Each of the first reflectors contains a ring resonator of the same size, and the delay for the light input to the input port of a first reflector to return there after being reflected is the same for all first reflectors.

Abstract: An optical semiconductor device includes a ring laser including a ring resonator in which an optical gain element having an optical gain by current injection is provided, a waveguide optically coupled to the ring laser, and a reflector provided at an end portion of the waveguide and configured to reverse the advancing direction of light outputted from the ring laser and propagating in the waveguide.

Abstract: A surface emitting laser element includes a lower DBR formed on a substrate; an active layer formed above the lower DBR; an upper DBR formed on the active layer. The upper DBR includes a dielectric multilayer that is formed as a result of dielectrics having different refractive indexes being alternately laminated and formed, a light shielding part is formed above the upper DBR, and the light shielding part has an opening at a central area for emitting light.

Abstract: There is provided a semiconductor laser device that enables flip-chip assembly by providing an embedding section around a mesa section, and has an improved emission lifetime. There is also provided a photoelectric converter and an optical information processing unit each having the semiconductor laser device. The semiconductor laser device includes: a mesa section including an active layer, and having a first electrode on a top surface; an embedding section covering the mesa section, and having a first connection aperture that reaches the first electrode; and a first wiring provided on the embedding section to be laid across the first connection aperture, the first wiring being electrically connected to the first electrode through the first connection aperture.

Abstract: A ring resonator is connected to an optical amplifier. The ring resonator and optical amplifier are contained within the optical path of an optical resonator formed by a first and second reflector. The optical coupler branches part of the light conducting from the optical amplifier to the ring resonator within the optical resonator off to an output optical waveguide.

Abstract: A diode laser includes a p-contact layer, a n-contact layer, and a wafer body disposed between the p-contact layer and the n-contact layer, the wafer body having a front end and a back end. The diode laser further includes a first grating comprising a plurality of grooves defined in the wafer body and extending between the front end and the back end at a first tilt angle, and a second grating comprising a plurality of grooves defined in the wafer body and extending between the front end and the back end at a second tilt angle, the second tilt angle opposite to the first tilt angle. A coupling region is defined in the wafer body by interleaving portions of the first grating and the second grating. The interleaving portions provide coherent coupling of laser beams flowing through the first grating and the second grating.

Abstract: The present invention intends to provide a surface-emitting laser light source using a two-dimensional photonic crystal in which the efficiency of extracting light in a direction perpendicular to the surface is high. In a laser light source provided with a two-dimensional photonic crystal layer created from a plate-shaped matrix body in which a large number of holes are periodically arranged and an active layer arranged on one side of the two-dimensional photonic crystal layer, the holes are created to be columnar with a predetermined cross-sectional shape such as a circular shape, and the main axis of each of the columnar holes is tilted to a surface of the matrix body. When provided with this two-dimensional photonic crystal layer, the surface-emitting laser source using a two-dimensional photonic crystal has a Q? value (i.e.

Abstract: An optoelectronic component contains an epitaxial layer sequence based on a nitride compound semiconductor having an active layer and an epitaxial growth substrate comprising Al1-xGaxN, where 0<x<0.95. In a method for producing an optoelectronic component an epitaxial growth substrate of Al1-x(InyGa1-y)xN or In1-xGaxN, where 0<x<0.99 and 0?y?1, is provided and an epitaxial layer sequence, which is based on a nitride compound semiconductor and contains an active layer, is grown thereon.

Abstract: In one example embodiment, a DFB laser includes a substrate; an active region positioned above the substrate; a grating layer positioned above the active region, the grating layer including a portion that serves as a primary etch stop layer; a secondary etch stop layer positioned above the grating layer; and a spacer layer interposed between the grating layer and the secondary etch stop layer.

Abstract: In accordance with one embodiment of the present disclosure, a DBR laser diode is provided where the wavelength selective grating of the laser diode is characterized by an aperiodically shifted grating phase ? and a Bragg wavelength ?B. The aperiodically shifted grating phase ? is substantially symmetric or substantially ?-shifted symmetric relative to a midpoint CL or shifted midpoint CL* of the DBR section. The phase ? of the wavelength selective grating is characterized by aperiodic phase jumps of magnitude ?J1, J2, . . . and segment lengths l0, 1, . . . . The phase jumps of the wavelength selective grating are arranged substantially symmetrically about a midpoint CL or shifted midpoint CL* of the DBR section along the optical axis of the DBR laser diode. At least two phase jumps reside on each side of the midpoint CL or shifted midpoint CL* of the DBR section.

Abstract: A semiconductor laser includes an active region including an active layer, and a diffraction grating and a phase shift which determine an oscillation wavelength, and a distributed reflector region including a light guide layer and a refection diffraction grating. The distributed reflector region has an effective diffraction grating period which varies along a direction of a cavity.

Abstract: A surface-emitting laser device is disclosed that includes a substrate connected to a heat sink; a first reflective layer formed of a semiconductor distributed Bragg reflector on the substrate; a first cavity spacer layer formed in contact with the first reflective layer; an active layer formed in contact with the first cavity spacer layer; a second cavity spacer layer formed in contact with the active layer; and a second reflective layer formed of a semiconductor distributed Bragg reflector in contact with the second cavity spacer layer. The first cavity spacer layer includes a semiconductor material having a thermal conductivity greater than the thermal conductivity of a semiconductor material forming the second cavity spacer layer.

Abstract: A semiconductor surface light-emitting element of this invention is provided with a photonic crystal layer 6 obtained by periodically forming a plurality of holes H in a basic layer 6A comprised of a first compound semiconductor of the zinc blend structure and growing embedded regions 6B comprised of a second compound semiconductor of the zinc blend structure, in the holes H, and an active layer 4 to supply light to the photonic crystal layer 6, in which a principal surface of the basic layer 6A is a (001) plane and in which side faces of each hole H have at least three different {100} facets.

Abstract: A gain clamped optical device includes a semiconductor stack and a resonant cavity configured to emit stimulated light. A window created in the optical device is configured to emit the stimulated light in an LED mode.

Abstract: The present invention discloses a method for fabricating a heat-resistant, humidity-resistant oxide-confined vertical-cavity surface-emitting laser (VCSEL) by slowing down the oxidizing rate during a VCSEL oxidation process to thereby reduce stress concentration of an oxidation layer and by preventing moisture invasion using a passivation layer disposed on a laser window. The VCSEL device thus fabricated is heat-resistant, humidity-resistant, and highly reliable. In a preferred embodiment, the oxidation process takes place at an oxidizing rate of less than 0.4 ?m/min, and the passivation layer is a SiON passivation layer.

Abstract: A diode laser and a laser resonator for a diode laser are provided, which has high lateral beam quality at high power output, requires little adjustment effort and is inexpensive to produce. The laser resonator according to the invention comprises a gain section (GS), a first planar Bragg reflector (DBR1) and a second planar Bragg reflector (DBR2), wherein the gain section (GS) has a trapezoidal design and the first planar Bragg reflector (DBR1) is arranged on a first base side of the trapezoidal gain section (GS) and the second planar Bragg reflector (DBR2) is arranged on the opposing base side of the trapezoidal gain section (GS), wherein the width (D1) of the first planar Bragg reflector (DBR1) differs from the width (D2) of the second planar Bragg reflector (DBR2).

Abstract: A laser apparatus uses a dysprosium doped chalcogenide glass fiber. The glass fiber has a laser pump operatively connected to it. The chalcogenide glass fiber is located in a laser cavity including one or more reflective elements such as a Bragg grating, a Bragg minor, a grating, and a non-doped fiber end face. The apparatus provides laser light output at a wavelength of about 4.3 ?m to about 5.0 ?m at a useful power level using laser light input at a wavelength of from about 1.7 ?m to about 1.8 ?m. Also disclosed is a method for providing laser light output at a wavelength of about 4.3 ?m to about 5.0 ?m using the apparatus of the invention.

Abstract: A vertical cavity surface emitting laser (VCSEL) system and method of fabrication are included. The VCSEL system includes a gain region to amplify an optical signal in response to a data signal and a first mirror arranged as a partially-reflective high-contrast grating (HCG) mirror at an optical output of the VCSEL system. The VCSEL system also includes a second mirror. The first and second mirrors can be arranged as a laser cavity to resonate the optical signal. The VCSEL system further includes a doped semiconductor region to generate a current through the first mirror in response to a voltage signal to substantially alter the reflectivity of the first mirror to provide Q-switching capability of the VCSEL system.

Abstract: The present disclosure is a vertical-cavity surface-emitting laser (VCSEL) device. A relief structure is formed above or below a light emitting region by partially removing an aluminum composition layer of VCESL through an etching process. Thus, profound static performances are obtained, including low power consumption, biggest operational speed, and high ratio of data transmission to power consumption as 2.9 and 9.2 Gbps/mW under 34 and 12.5 Gbps, respectively.

Abstract: A surface-emitting laser device includes a lower reflector, a resonator structure having an active layer and an upper reflector on an inclined substrate, and an emission region emitting laser light enclosed by an electrode. The upper reflector includes a confinement structure having a current passing region enclosed by an oxide containing at least an oxide generated as a result of partial oxidation of a layer containing aluminum subject to selective oxidation, and a dielectric film formed within the emission region, the dielectric film at least enclosing a partial region including a center of the emission region. In viewing from a direction orthogonal to the emission region, a center of a region enclosed by the dielectric film is located at a position distant from the center of the emission region based on a size of the confinement structure relative to a direction orthogonal to an inclined axis of the inclined substrate.

Abstract: A semiconductor laser according to the present invention includes a first reflective region and a second reflective region disposed opposite to the first reflective region in a predetermined direction of an optical axis. The first reflective region has a plurality of gain waveguides each including an active layer and a plurality of refractive-index controlling waveguides each having a first diffraction grating formed therein. The gain waveguides and the refractive-index controlling waveguides are alternately arranged at a predetermined pitch in the direction of the optical axis. The second reflective region has a second diffraction grating.

Abstract: A semiconductor laser includes a columnar lamination structure including a first multi-layer reflection mirror, a first spacer layer, an AlxGayIn1-x-yP (where 0?x<1 and 0<y<1) based active layer, a second spacer layer, a second multi-layer reflection mirror, and a lateral mode adjusting layer on a substrate in this order from the substrate and including a current narrowing layer. The current narrowing layer includes an unoxidized region in an in-plane central region and a circular oxidized region in the circumference of the unoxidized region. The later mode adjusting layer includes a high reflection region to correspond to the unoxidized region and a circular low reflection region in the circumference of the high reflection region. On the assumption that a diameter of the unoxidized region is Dox and a diameter of the high reflection region is Dhr, the diameters Dox and Dhr satisfy an expression of 0.8<Dhr/Dox<1.5.

Abstract: A wavelength tunable laser diode (LD) is disclosed. The LD provides a SG-DFB region and a CSG-DBR region. The SG-DFB region shows a gain spectrum with a plurality of gain peaks, while, the CSG-DBR region shows a reflection spectrum with a plurality of reflection peaks. The LD may emit light with a wavelength at which the one of the gain peaks and one of the reflection peaks coincides. In the present LD, both the gain spectrum and the reflection spectrum are modified by adjusting the temperature of the SG-DFB region and that of the CSG-DBR region independently.

Abstract: High-efficiency method and device, to produce coherent Smith-Purcell radiation. A conductive diffraction grating, delimited by two conductive walls, is used, and an electron beam is passed above the grating to generate the radiation. According to the invention, the speed of the electrons is sufficiently low in order that, in a diagram (wave number k, frequency f), the beam line (I) intersects a portion (V) of a branch of the dispersion relationship, located in the first Brillouin zone, and corresponding to the grating's fundamental mode, at a point (P) located outside the zone delimited by the light lines (III, IV), and the current density of the beam is sufficiently high to excite the grating's fundamental mode which is radiated towards the outside thereof.

Abstract: An electronic device comprising a multilayer semiconductor structure formed by a periodic structure having a first semiconductor layer and a second semiconductor layer, wherein in at least a portion of the multilayer semiconductor structure, the first semiconductor layer and the second semiconductor layer have different conduction types. The first semiconductor layer and the second semiconductor layer have different refractive indexes, and the multilayer semiconductor structure functions as a multilayer reflective mirror. As a result, an electronic device, a surface emitting laser, a surface emitting laser array, a light source, and an optical module with decreased parasitic capacitance can be realized.

Abstract: Surface emitting laser structures that include a partially reflecting element disposed in the laser optical cavity are disclosed. A vertical external cavity surface emitting laser (VECSEL) structure includes a pump source configured to emit radiation at a pump wavelength, ?pump, an external out-coupling reflector, a distributed Bragg reflector (DBR,) and an active region arranged between the DBR and the out-coupling reflector. The active region is configured to emit radiation at a lasing wavelength, ?lase. The VECSEL structure also includes partially reflecting element (PRE) arranged between the gain element and the external out-coupling reflector. The PRE has reflectivity of between about 30% and about 70% for the radiation at the lasing wavelength and reflectivity of between about 30% and about 70% for the radiation at the pump wavelength.

Abstract: A tunable laser includes a substrate comprising a silicon material and a gain medium coupled to the substrate. The gain medium includes a compound semiconductor material. The tunable laser also includes a waveguide disposed in the substrate and optically coupled to the gain medium, a first wavelength selective element characterized by a first reflectance spectrum and disposed in the substrate, and a second wavelength selective element characterized by a second reflectance spectrum and disposed in the substrate. The tunable laser further includes an optical coupler disposed in the substrate and joining the first wavelength selective element, the second wavelength selective element, and the waveguide and an output mirror.

Abstract: A disclosed surface-emitting laser element includes a lower DBR formed on a substrate, an active layer formed on the lower DBR, an upper DBR formed on the active layer, a wavelength-adjusting layer formed above the active layer, and a plurality of surface-emitting lasers configured to emit respective laser beams having different wavelengths by changing a thickness of the wavelength-adjusting layer. In the surface-emitting laser element, the wavelength-adjusting layer includes one of a first film having alternately layered GaInP and GaAsP and a second film having alternately layered GaInP and GaAs, the thickness of the wavelength-adjusting layer being changed by partially removing each of the alternating layers of a corresponding one of the first and second films.

Abstract: A tunable pulsed laser includes a substrate comprising a silicon material and a gain medium coupled to the substrate. The gain medium includes a compound semiconductor material. The tunable pulsed laser also includes a waveguide disposed in the substrate and optically coupled to the gain medium, an optical modulator optically coupled to the gain medium, a first wavelength selective element characterized by a first reflectance spectrum and disposed in the substrate, and a second wavelength selective element characterized by a second reflectance spectrum and disposed in the substrate. The tunable pulsed laser further includes an optical coupler disposed in the substrate and joining the first wavelength selective element, the second wavelength selective element, and the waveguide and an output mirror.

Abstract: Semiconductor devices are described that include a vertical cavity surface emitting laser (VCSEL) and a structure formed on or near the surface of the VCSEL that acts as a filter that benefits high-frequency VCSEL modulation performance.

Abstract: A method and apparatus for protecting the seed laser in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system are disclosed in one embodiment, a Bragg AOM is used as a switch on the beam path from the seed laser to other optical components and ultimately to an irradiation site. Power is applied to the Bragg AOM and pulses from the seed laser are thus deflected onto the desired beam path rather than passing straight through the Bragg AOM. Once the pulses have passed through the Bragg AOM, power to the Bragg AOM ceases, so that any reflections from the irradiation site will pass straight through the Bragg AOM and will not be deflected back to the seed laser. Use of the Bragg AOM rather than components previously used results in lower power consumption and better protection for the seed laser.

Abstract: A surface emitting laser element is disclosed. The surface emitting laser element includes a resonator structural body including an active layer, first and second semiconductor distributed Bragg reflectors which sandwich the resonator structural body, and a confinement structure which can confine an injection current and a lateral mode of oscillation light at the same time by being formed with selective oxidation of a layer to be selectively oxidized containing aluminum in the first semiconductor distributed Bragg reflector. A thickness of the layer to be selectively oxidized is 28 nm, and a temperature when an oscillation threshold current becomes a minimum value is approximately 17° C.

Abstract: Apparatus and method for generating controlled-linewidth laser-seed-signals for high-powered fiber-laser amplifier systems. In some embodiments, the natural chirp (frequency change of laser light over a short start-up time) of a DBR laser diode when driven by pulsed current is used to broaden the linewidth of the laser output, while adjusting the peak current and/or the pulse duration to obtain the desired linewidth.

Abstract: A semiconductor laser has a first diffractive grating area. The first diffractive grating area has a plurality of segments. Each segment has a first area including a diffractive grating and a second area that is space area combined to the first area. Optical lengths of at least two of the second areas are different from each other. A refractive-index of each of the segments are changeable.