Abstract: A method of forming a flip chip backside Vertical Cavity Surface Emitting Laser (VCSEL) package comprising: forming a VCSEL pillar array; applying a dielectric layer to the VCSEL pillar array, the dielectric layer filling trenches in between pillars forming the VCSEL pillar array and covering the pillars; planarizing the VCSEL pillar array to remove the dielectric layer covering the pillars exposing a metal layer on a top surface of the pillars; applying a metal coating on the metal layer on a top surface of the pillars, the metal layer defining a contact pattern of the VCSEL pillar array; and applying solder on the metal coating to flip chip mount the VCSEL pillar array to a substrate package.

Abstract: A light emitting device includes: a substrate including a main surface; a first projection positioned on the main surface, the first projection including an upper surface and first and second lateral surfaces, wherein the first lateral surface of the first projection comprises a first reflective part, and the second lateral surface of the first projection comprises a second reflective part; a first laser element configured to irradiate laser light to the first reflective part; a second laser element configured to irradiate laser light to the second reflective part; and a first optical member fixed to the upper surface of the first projection, wherein the first optical member comprises a first lens part positioned above the first reflective part, and a second lens part positioned above the second reflective part.

Abstract: Superluminescent light emitting diode, SLED, devices and modules are provided. A multi-wavelength SLED device is fabricated by sequentially depositing adjacent epitaxial stacks onto a substrate to form a monolithic chip structure. Each epitaxial stack includes n-type layers, active layers and p-type layers. A ridge is formed in the p-type layers between the end facets of the chip to induce a waveguiding region in the active layers. Different ones of the epitaxial stacks emit at different wavelength ranges. A module is made by packaging one of the above SLED devices with another SLED device, with one inverted relative to the other to form a triangle of emitters as viewed end on, for example a triangle of red, green and blue emitters. The SLED devices and modules may find use in projection, endoscopic, fundus imaging and optical coherence tomography systems.

Abstract: A three-color light source 1 is a three-color light source that combines red, green, and blue laser light so as to output light. The three-color light source 1 includes a red LD 11, a green LD 12, a blue LD 13, a first collimator lens 61, a second collimator lens 62, a third collimator lens 63, a first wavelength filter 81, a second wavelength filter 82, a carrier 30 that is equipped with the LDs 11 to 13, the collimator lenses 61 to 63, and the wavelength filters 81 and 82, and a TEC 40 that is equipped with the carrier 30. The red LD 11 is formed of a GaAs-based material, and the green LD 12 and the blue LD 13 are formed of GaN-based materials.

Abstract: An optical sensor, an optical examination device, and a method of detecting optical properties. The optical sensor includes an irradiation system including light irradiator to irradiate a test object with light, and a detection system to detect the light that is emitted from the irradiation system to the test object and has propagated through the test object. The light irradiator includes a multilayered structure having an active layer, and the multilayered structure includes a surface-emitting laser element and a photo-sensing element optically connected to the surface-emitting laser element. The optical examination device includes the optical sensor, and a controller to calculate optical properties of the test object based on a detection result of the optical sensor. The method includes performing optical simulation to obtain a detection light quantity distribution for an optical model and performing inverse problem estimation.

Abstract: The method includes preparing a plurality of light-emitting units, one of the plurality of light-emitting units comprising an electrode, a light-emitting stack, and a protection layer with a first part covering the electrode and a second part which comprises a portion surrounding the electrode and covers the light-emitting stack; removing the portion without removing the first part; forming a wavelength conversion layer on the first part and the light-emitting stack not covered by the second part; and removing the first part to substantially expose the electrode.

Abstract: An integrated semiconductor device includes a substrate including first, second and third portions; a first waveguide provided on the first portion, the first waveguide including a first base portion containing a first core layer, and a first ridge portion provided on the first base portion; a second waveguide provided on the second portion, the second waveguide including a second base portion containing a second core layer and a second ridge portion provided on the second base portion; and a third waveguide provided on the third portion, the third waveguide including a stripe-shaped mesa containing a third core layer. The second base portion is connected to the first base portion. The second ridge portion is connected to the first ridge portion and the stripe-shaped mesa. The second core layer is formed integrally with the third core layer and is joined to the first core layer by a butt-joint method.

Abstract: An integrated semiconductor device includes a substrate including a first portion, a second portion, and a third portion; a first waveguide provided on the first portion, the first waveguide including a base portion and a ridge portion provided on the base portion, the base portion containing a first core layer; a second waveguide provided on the second portion, the second waveguide including a first stripe-shaped mesa containing a second core layer; and a third waveguide provided on the third portion, the third waveguide including a second stripe-shaped mesa containing a third core layer. The first stripe-shaped mesa is connected to the base portion and the ridge portion. The first stripe-shaped mesa is connected to the second stripe-shaped mesa. The second core layer is formed integrally with the first core layer. The third core layer is joined to the second core layer by a butt-joint method.

Abstract: An optical waveguide directional coupler includes a base having a planar member and a ridge member and an optical waveguide in the base. The ridge member extends from the planar member and has an upper surface where the optical waveguide exposed. The optical waveguide includes a first flat side surface, a second flat side surface parallel to the first flat side surface, a third flat side surface, a fourth flat side surface parallel to the third flat side surface, and a first flat connection side surface. An included angle ?1 between the first and third flat side surfaces is an obtuse angle, an included acute angle ?1 is formed between the first flat connection side surface and the second flat side surface, and ?1 and ?1 satisfy ?1<(180°??1).

Abstract: The invention relates to a laser (1) with a laser chip (10) having a plurality of active laser channels (20), a front facet (10a) for coupling out the laser radiation of the laser channels (20) and a rear facet (10b) for rear—side reflection of the laser radiation of the laser channels (20) in the direction of the front facet (10a); an external resonator (50) which couples a portion of the radiation exiting the laser chip (10) at the front facet (10a) back into the laser chip (10) and, by said back-coupling, couples the radiation of the laser channels (20) with one another; wherein at least one of the laser channels (20) is curved at least sectionally and—in the far field—in addition to a main beam (P3), at least one secondary beam (P1, P2) is divergently emitted by the laser chip (10); and wherein the resonator (50) reflects at least one of the secondary beams (P1, P2), which is—in the far field—divergently emitted by the laser chip (10) next to a main beam (P3), in the direction of the laser chip (10).

Abstract: An optical device includes a gain medium on a substrate. The device also includes one or more laser cavities and an amplifier on the substrate. The one or more laser cavities each guides a light signal through a different region of the gain medium such that each of the light signals is amplified within the gain medium. The amplifier guides an amplified light signal through the gain medium such that the amplified light signal is amplified in the gain medium.

Abstract: A method and device for emitting electromagnetic radiation at high power using nonpolar or semipolar gallium containing substrates such as GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, is provided. In various embodiments, the laser device includes plural laser emitters emitting green or blue laser light, integrated a substrate.

Abstract: Apparatuses and methods for high density laser optics are provided. An example, of a laser optics apparatus includes a plurality of vertical cavity surface emitting lasers (VCSELs) in a monolithically integrated array, a high contrast grating (HCG) integrated with an aperture of a vertical cavity of each of the plurality of the VCSELs to enable emission of a single lasing wavelength of a plurality of lasing wavelengths, and a plurality of single mode waveguides, each integrated with a grating coupler, that are connected to each of the plurality of the integrated VCSELs and the HCGs, where each of the grating couplers is aligned to an integrated VCSEL and HCG.

Abstract: Various embodiments of a multi-laser system are disclosed. In some embodiments, the multi-laser system includes a plurality of lasers, a plurality of laser beams, a beam positioning system, a thermally stable enclosure, and a temperature controller. The thermally stable enclosure is substantially made of a material with high thermal conductivity such as at least 5 W/(m K). The thermally stable enclosure can help maintain alignment of the laser beams to a target object over a range of ambient temperatures.

Abstract: A multi-wavelength semiconductor laser device includes: first and second device sections monolithically formed on a substrate; and a rear end face film formed together on a rear end face of each of the first and second device sections. The first device section is a light-emitting device section having an oscillation wavelength of ?1. The second device section is a light-emitting device section having an oscillation wavelength of ?2 (?1<?2). The rear end face film includes a layer in which N sets (N?2) of layers each having the combination of a low refractive index layer having a refractive index of n1 and a high refractive index layer having a refractive index of n3 (n1<n3) as one set are laminated, and an intermediate refractive index layer having a refractive index of n2 (n1<n2<n3) in order from the rear end face side, and is constituted by a film different from an Si film.

Abstract: A surface emitting laser device includes a substrate, a lower reflector, an active layer, an upper reflector, and surface emitting lasers configured to emit light. A second phase adjustment layer, a contact layer, a first phase adjustment layer, and a wavelength adjustment layer are successively layered from the active layer side. The total optical thickness from the active layer side of the second phase adjustment layer to the midsection of the wavelength adjustment layer is approximately (2N+1)×?/4, where ? represents a wavelength of light, and N represents a positive integer. The optical thickness from the active layer side of the second phase adjustment layer to the midsection of the contact layer is approximately N?/2. At least two of the surface emitting lasers have the wavelength adjustment layer arranged at different thicknesses and are configured to emit light with different wavelengths.

Abstract: Apparatuses and methods for high density laser optics are provided. An example, of a laser optics apparatus includes a plurality of vertical cavity surface emitting lasers (VCSELs) in a monolithically integrated array, a high contrast grating (HCG) integrated with an aperture of a vertical cavity of each of the plurality of the VCSELs to enable emission of a single lasing wavelength of a plurality of lasing wavelengths, and a plurality of single mode waveguides, each integrated with a grating coupler, that are connected to each of the plurality of the integrated VCSELs and the HCGs, where each of the grating couplers is aligned to an integrated VCSEL and HCG.

Abstract: Provided is a III-nitride semiconductor laser diode which is capable of lasing at a low threshold. A support base has a semipolar or nonpolar primary surface. The c-axis Cx of a III-nitride is inclined relative to the primary surface. An n-type cladding region and a p-type cladding region are provided above the primary surface of the support base. A core semiconductor region is provided between the n-type cladding region and the p-type cladding region. The core semiconductor region includes a first optical guide layer, an active layer, and a second optical guide layer. The active layer is provided between the first optical guide layer and the second optical guide layer. The thickness of the core semiconductor region is not less than 0.5 ?m. This structure allows the confinement of light into the core semiconductor region without leakage of light into the support base, and therefore enables reduction in threshold current.

Abstract: A laser frequency converter includes a first substrate material forming a first planar surface that includes a first nonlinear material situated along a portion of the first planar surface of the first substrate material to perform a frequency conversion of a laser signal. The frequency converter includes a second substrate material forming a second planar surface and separated by a distance from the first planar surface of the first substrate material. The second substrate material includes a second nonlinear material situated along a portion of the second planar surface of the second substrate material to perform the frequency conversion of the laser signal in conjunction with the first non-linear material. The second nonlinear material is offset from the first nonlinear material along an axis of propagation for the laser signal.

Abstract: Provided is a multi-wavelength laser diode module including a plurality of laser diodes having different consecutive light emission wavelength regions, a plurality of filters respectively corresponding to the plurality of laser diodes, and an optical waveguide path that transmits light emitted from the plurality of laser diodes to the plurality of filters and collects light reflected or transmitted by the plurality of filters to transmit the collected light to the outside.

Abstract: A wavelength-tunable light source includes light sources having differing variable wavelength regions, where light sources having adjacent wavelength regions are distributed to different systems. The light sources are each set such that an end portion of the variable wavelength region of the light source overlaps an end portion of the variable wavelength region of another light source. A control unit selects and drives a first light source of a first system, varies a wavelength of the first light source, selects a second light source that is of a second system among the different systems and that has a wavelength region overlapping the variable wavelength region of the first light source, drives the second light source concurrently with the first light source and subsequently switches to the output light of the second light source, causing wavelength variation and executing continuous wavelength variation over a wide range.

Abstract: Embodiments of the invention describe an illuminator having a light source to originate an illumination beam, wherein the light source further comprises a set of vertical-cavity surface emitting lasers (VCSELs), including a first VCSEL having a first laser emission wavelength, and a second VCSEL having a second laser emission wavelength different than the first laser emission wavelength. Thus, by varying laser emission wavelengths of VCSELs in a VCSEL array, embodiments of the invention produce low-contrast speckle, and do not limit the imaging capabilities of the host illumination system. In some embodiments of the invention, vertical external cavity surface emitting lasers (VECSELs) are utilized to produce the above described varying laser emission wavelengths.

Abstract: Implementations and techniques for coupled asymmetric quantum confinement structures are generally disclosed.

Abstract: The thermal processing device includes a stage, a continuous wave electromagnetic radiation source, a series of lenses, a translation mechanism, a detection module, a three-dimensional auto-focus, and a computer system. The stage is configured to receive a substrate thereon. The continuous wave electromagnetic radiation source is disposed adjacent the stage, and is configured to emit continuous wave electromagnetic radiation along a path towards the substrate. The series of lenses is disposed between the continuous wave electromagnetic radiation source and the stage, and are configured to condense the continuous wave electromagnetic radiation into a line of continuous wave electromagnetic radiation on a surface of the substrate. The translation mechanism is configured to translate the stage and the line of continuous wave electromagnetic radiation relative to one another. The detection module is positioned within the path, and is configured to detect continuous wave electromagnetic radiation.

Abstract: Techniques, devices and systems for optical communications based on wavelength division multiplexing (WDM) that use tunable multi-wavelength laser transmitter modules.

Abstract: A multi-wavelength laser array of a plurality of emitters in a diode bar or stack where each beam is deflected by a different angle to be incident upon a uniform volume holographic grating with a portion of the beam being deflected as a feedback portion while a further portion provides a wavelength tuned output unique to each emitter. The arrangement of a uniform volume holographic grating with deflectors such as phaseplates eliminates the need to use expensive wavelength chirped gratings.

Abstract: A transmitter is disclosed including a laser array comprising a plurality of lasers spatially offset from one another and each having a laser output having a unique wavelength. A first prism is positioned to impart a first angular shift to the laser outputs to produce and a second prism is positioned to impart a second angular shift opposite the first angular shift on the outputs. An index modulating element is coupled to one of the first and second prisms and a controller is electrically coupled to the index modulating element to control an angle of light output form the second prism. An optical spectrum reshaper may be positioned between the second prism and the lens and have at least one transmission edge aligned with the wavelength at least one of the lasers.

Abstract: Integrated are: semiconductor lasers of distributed feedback type that oscillate in single mode at emission wavelengths different from one another; a coupler that has as many input ports as the semiconductor lasers, the input ports to which output light from the semiconductor lasers are input, the coupler guiding and outputting the output light; and an amplifier that amplifies the output light from the coupler, and a predetermined relation holds true, where “N” is the number of the semiconductor lasers, “Ldfb” is a cavity length of each of the semiconductor lasers, “??0” is a spectral linewidth of laser light output therefrom, “Lsoa” is an amplifier length of the amplifier, “A” is an amplification factor of the amplifier, “??” is a spectral linewidth of amplified laser light output therefrom, and “R” is ??/??0.

Abstract: A laser source assembly for providing an assembly output beam includes a first emitter, a second emitter, and a third emitter. The first emitter emits a first beam along a first beam axis that is substantially parallel to and spaced apart from an assembly axis. The second emitter emits a second beam along a second beam axis that is substantially parallel to and spaced apart from the assembly axis. The third emitter emits a third beam along a third beam axis that is substantially parallel to and spaced apart from the assembly axis. The first beam axis, the second beam axis and the third beam axis are positioned spaced apart about and substantially equidistant from the assembly axis.

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: A multi-wavelength semiconductor laser device includes a block having a V-shaped groove with two side faces extending in a predetermined direction; and laser diodes with different light emission wavelengths mounted on the side faces of the groove in the block so that their laser beams are emitted in the predetermined direction.

Abstract: An illuminating device includes at least first and second nitride-based semiconductor light-emitting elements each having a semiconductor chip with an active layer region. The active layer region is at an angle of 1° or more with an m plane, and an angle formed by a normal line of a principal surface in the active layer region and a normal line of the m plane is 1° or more and 5° or less. The first and second nitride-based semiconductor light-emitting elements have thicknesses of d1 and d2, respectively, and emit the polarized light having wavelengths ?1 and ?2, respectively, where the inequalities of ?1<?2 and d1<d2 are satisfied.

Abstract: A high-brightness laser module is configured with a beam-compression unit capable of reducing a diameter of parallel light beams which are emitted by respective spaced apart individual laser diodes. The module further has an objective lens configured to losslessly launch the light with the reduced diameter into a fiber.

Abstract: Implementations and techniques for coupled asymmetric quantum confinement structures are generally disclosed.

Abstract: In this semiconductor laser apparatus, a first wire-bonding portion is arranged at a position in a fourth direction from a first semiconductor laser device and in a first direction from a photodetector, and a second wire-bonding portion is arranged at a position in the fourth direction from the first semiconductor laser device and in a third direction from the first wire-bonding portion. A third wire-bonding portion is arranged at a position in a second direction from a third semiconductor laser device and in the first direction from the photodetector, and a fourth wire-bonding portion is arranged at a position in the second direction from the third semiconductor laser device and in the third direction from the third wire-bonding portion.

Abstract: A light-emitting device formed by easily mounting a light-emitting element onto a supporting base and a method of manufacturing the light-emitting device are provided. A light-emitting device includes: a supporting base including a depression section on a top surface thereof, the depression section having an inclined surface on a side wall thereof; a first light-emitting element arranged on a bottom surface of the depression section; and a second light-emitting element arranged on the first light-emitting element and the supporting base.

Abstract: Vertical Cavity Surface Emitting Laser (VCSEL) arrays with vias for electrical connection are disclosed. A Vertical Cavity Surface Emitting Laser (VCSEL) array in accordance with one or more embodiments of the present invention comprises a plurality of first mirrors, a plurality of second mirrors, a plurality of active regions, coupled between the plurality of first mirrors and the plurality of second mirrors, and a heatsink, thermally and mechanically coupled to the second mirror opposite the plurality of active regions, wherein an electrical path to at least one of the plurality of second mirrors is made through a via formed through a depth of the plurality of second mirrors, and a plurality of VCSELs in the VCSEL array are connected in series.

Abstract: A diode-laser bar stack includes a plurality of diode-laser bars having different temperature dependent peak-emission wavelengths. The stack is arranged such that the bars can be separately powered. This allows one or more of the bars to be “on” while others are “off”. A switching arrangement is described for selectively turning bars on or off, responsive to a signal representative of the temperature of the diode-laser bar stack, for providing a desired total emission spectrum.

Abstract: Integrated are: semiconductor lasers of distributed feedback type that oscillate in single mode at emission wavelengths different from one another; a coupler that has as many input ports as the semiconductor lasers, the input ports to which output light from the semiconductor lasers are input, the coupler guiding and outputting the output light; and an amplifier that amplifies the output light from the coupler, and a predetermined relation holds true, where “N” is the number of the semiconductor lasers, “Ldfb” is a cavity length of each of the semiconductor lasers, “??0” is a spectral linewidth of laser light output therefrom, “Lsoa” is an amplifier length of the amplifier, “A” is an amplification factor of the amplifier, “??” is a spectral linewidth of amplified laser light output therefrom, and “R” is ??/??0.

Abstract: Emissive quantum photonic imagers comprised of a spatial array of digitally addressable multicolor pixels. Each pixel is a vertical stack of multiple semiconductor laser diodes, each of which can generate laser light of a different color. Within each multicolor pixel, the light generated from the stack of diodes is emitted perpendicular to the plane of the imager device via a plurality of vertical waveguides that are coupled to the optical confinement regions of each of the multiple laser diodes comprising the imager device. Each of the laser diodes comprising a single pixel is individually addressable, enabling each pixel to simultaneously emit any combination of the colors associated with the laser diodes at any required on/off duty cycle for each color. Each individual multicolor pixel can simultaneously emit the required colors and brightness values by controlling the on/off duty cycles of their respective laser diodes.

Abstract: The present invention is directed to a semiconductor laser device comprising a first resonator section for resonating an optical resonator signal for providing an optical output signal at an output of said laser device, wherein said first resonator section is arranged for selectively resonating at a plurality of discrete output wavelengths, and wherein said laser device further comprises a second resonator section operatively connected to said first resonator section, said second resonator section being arranged for providing an optical feedback signal at a feedback wavelength to said first resonator section for locking said first resonator section into resonating at a selected output wavelength of said discrete output wavelengths, which selected output wavelength corresponds to said feedback wavelength for providing said optical output signal.

Abstract: Implementations and techniques for coupled asymmetric quantum confinement structures are generally disclosed.

Abstract: A semiconductor laser module includes a semiconductor laser unit and a light selecting unit. The semiconductor laser unit includes a semiconductor laser substrate and a plurality of distributed reflector semiconductor laser devices formed on the semiconductor laser substrate in an array. Each of the distributed reflector semiconductor laser devices is configured to emit a laser light of a different wavelength from an output facet. The light selecting unit includes a light selecting device substrate and a light selecting device formed on the light selecting device substrate. The light selecting device is configured to selectively output a laser light emitted from a distributed reflector semiconductor laser device. The semiconductor laser unit and the light selecting unit are attached to each other in such a manner that the light selecting device is optically coupled to the distributed reflector semiconductor laser devices.

Abstract: There is provided an optical interconnection system including a plurality of semiconductor integrated devices each including a surface emitting laser array device including a plurality of surface emitting laser devices each emitting an output laser signal light of a different wavelength modulated based on an input modulated signal, a silicon optical waveguide that guides output laser signal lights emitted from the surface emitting laser devices of each of the semiconductor integrated devices to another semiconductor integrated device, a plurality of optical couplers respectively corresponding to the semiconductor integrated devices and guiding the output laser signal lights to the silicon optical waveguide, and a plurality of optical splitters respectively corresponding to the semiconductor integrated devices, receiving the output laser signal lights guided by the silicon optical waveguide, and inputting an input laser signal light to a corresponding one of the semiconductor integrated devices.

Abstract: A multiwavelength optical device includes a substrate; a first mirror section including a plurality of first mirror layers stacked on the substrate; an active layer stacked on the first mirror section, the active layer including a light emission portion; a second mirror section including a plurality of second mirror layers stacked on the active layer; a first electrode disposed between the active layer and the second mirror section; and a second electrode disposed between the first mirror section and the active layer.

Abstract: A light emitting device includes: a support base; a first light emitting element which is provided at one surface side of the support base and has a first substrate; and a second light emitting element which is provided between the first light emitting element and the support base and has a second substrate, which has a light emitting section as a semiconductor layer and a peripheral section other than the light emitting section at the first light emitting element side of the second substrate, and which has an embedded layer formed of a material with higher heat conductivity than the semiconductor layer in the peripheral section.

Abstract: A multi-beam semiconductor laser apparatus includes three or more stripe semiconductor laser emission units which are arranged on a substrate, isolation grooves which separate the semiconductor laser emission units from each other, and pad electrodes which are disposed on outer sides of the outermost semiconductor laser emission units. The isolation grooves are formed between the pad electrodes and the semiconductor laser emission units adjacent to the pad electrodes and between adjacent semiconductor laser emission units. A distance between two isolation grooves formed on outer sides of the outermost semiconductor laser light emission units is smaller than a distance between two isolation grooves formed on both sides of inner ones of the semiconductor laser light emission units.

Abstract: A semiconductor light emitting device downsized by devising arrangement of connection pads is provided. A second light emitting device is layered on a first light emitting device. The second light emitting device has a stripe-shaped semiconductor layer formed on a second substrate on the side facing to a first substrate, a stripe-shaped p-side electrode supplying a current to the semiconductor layer, stripe-shaped opposed electrodes that are respectively arranged oppositely to respective p-side electrodes of the first light emitting device and electrically connected to the p-side electrodes of the first light emitting device, connection pads respectively and electrically connected to the respective opposed electrodes, and a connection pad electrically connected to the p-side electrode. The connection pads are arranged in parallel with the opposed electrodes.

Abstract: A semiconductor laser includes a light emission end facet; a first optical waveguide extending in a predetermined optical-axis direction, the first optical waveguide being optically coupled to the light emission end facet; a ring resonator having a plurality of periodic transmittance peak wavelengths, the ring resonator being optically coupled to the first optical waveguide; a plurality of gain waveguides that generate light by injection of current; an optical coupler portion that optically couples the first optical waveguide to each of the plurality of gain waveguides; and a plurality of second optical waveguides including diffraction gratings, the plurality of second optical waveguides being respectively optically coupled to the plurality of gain waveguides. Also, each of the diffraction gratings in the plurality of second optical waveguides has a different reflection band.

Abstract: Techniques, devices and systems for optical communications based on wavelength division multiplexing (WDM) that use tunable multi-wavelength laser transmitter modules.