Abstract: There is provided a novel surface emitting laser structure unnecessary to have multilayer mirrors in both of upper and lower sides of an active layer. A surface emitting laser comprises a two-dimensional periodic structure which is comprised of an active material having a gain in a specific wavelength band of electromagnetic waves, and a reflecting mirror arranged apart by a predetermined distance so as to face the above-mentioned two-dimensional periodic structure, and these are comprised so as to make laser oscillation possible. At that time, the above-mentioned two-dimensional periodic structure is formed of a two-dimensional photonic crystal which is comprised of a dielectric, and a resonator is comprised of a reflecting mirror pair formed by combination with the above-mentioned reflecting mirror to make laser oscillation generated.

Abstract: The present invention includes a vertical-cavity surface-emitting semiconductor laser diode having a resonator with a first distributed Bragg reflector, an active zone which has a p-n junction and is embedded into a semiconductor layer sequence, and a second distributed Bragg reflector. The semiconductor laser diode has an emission wavelength ?, wherein a periodic structure is arranged within the resonator as an optical grating made of semiconductive material and dielectric material, the main plane of extension of which is arranged substantially perpendicularly to the direction of emission of the semiconductor laser diode. The periodic structure is in direct contact with at least one of the semiconductor layers embedding the active zone and with at least one of the two distributed Bragg reflectors.

Abstract: A VCSEL includes a first distributed Bragg reflector (DBR) of a first conductivity type formed on a substrate and including at least one semiconductor layer to be oxidized, an active region having a column shaped structure and formed on the first DBR, and a second DBR of a second conductivity type. At least one hole starting from a surface of the first DBR and reaching the at least one semiconductor layer to be oxidized is formed in the first DBR outside of a column shaped structure of the second DBR. An oxidized region is formed in the semiconductor layer to be oxidized by selectively oxidizing from a side surface of the hole. In the first DBR, a first current path is formed by a conductive region surrounded by the oxidized region, and a second current path is formed by a conductive region not surrounded by the oxidized region.

Abstract: A surface-emission laser device comprises an active layer, cavity spacer layers provided at both sides of the active layer, reflection layers provided at respective sides of the cavity spacer layers, the reflection layers reflecting an oscillation light oscillated in the active layer and a selective oxidation layer. The selective oxidation layer is provided between a location in the reflection layer corresponding to a fourth period node of the standing wave distribution of the electric field of the oscillating light and a location in the reflection layer adjacent to the foregoing fourth period node in the direction away from the active layer and corresponding to an anti-node of the standing wave distribution of the electric field of the oscillation light.

Abstract: A semiconductor optical device includes a silicon substrate and a Group III-V semiconductor gain layer. The Group III-V semiconductor gain layer is formed on the silicon substrate. The silicon substrate or the Group III-V semiconductor gain layer has a dispersion Bragg grating formed therein. In a method of manufacturing a semiconductor optical device, a Group III-V semiconductor gain layer is formed on a silicon substrate. A dispersion Bragg grating is formed on the silicon substrate or the Group III-V semiconductor gain layer.

Abstract: A method of manufacturing a nitride semiconductor light emitting element includes: forming a stacked layer body of a nitride semiconductor having a second conductive-type layer, a light emitting layer, and a first conductive-type layer stacked on a growth substrate in this order; forming a first Bragg reflector made of a dielectric multilayer film above the first conductive-type layer; forming a first electrode over the first Bragg reflector with the first electrode being electrically connected to the first conductive-type layer; bonding the stacked layer body to a supporting substrate via the first Bragg reflector and the first electrode; removing the growth substrate from the stacked layer body to expose the second conductive-type layer; and forming over the exposed second conductive-type layer a second electrode and a second Bragg reflector made of a dielectric multilayer film so that the second Bragg reflector faces the first Bragg reflector across the stacked layer body.

Abstract: A polymer film laser is provided that comprises a plurality of extruded polymer layers. The plurality of extruded polymer layers comprises a plurality of alternating dielectric layers of a first polymer material having a first refractive index and a second polymer material having second refractive index different than the first refractive index.

Abstract: In one embodiment, a method of producing an optoelectronic nanostructure includes preparing a substrate; providing a quantum well layer on the substrate; etching a volume of the substrate to produce a photonic crystal. The quantum dots are produced at multiple intersections of the quantum well layer within the photonic crystal. Multiple quantum well layers may also be provided so as to form multiple vertically aligned quantum dots. In another embodiment, an optoelectronic nanostructure includes a photonic crystal having a plurality of voids and interconnecting veins; a plurality of quantum dots arranged between the plurality of voids, wherein an electrical connection is provided to one or more of the plurality of quantum dots through an associated interconnecting vein.

Abstract: To provide a structure having a photonic crystal that can display a reflection function using GR even when a refractive index difference between a photonic crystal layer and a cladding layer adjacent thereto is not sufficient and a surface-emitting laser using the structure. The structure includes a photonic crystal layer including a first member of a flat shape and plural pillars arrayed two-dimensionally periodically on the first member. The photonic crystal layer is formed of a first material having a first refractive index. A low refractive index layer formed of a second material having a second refractive index lower than the first refractive index is adjacent to the photonic crystal layer. A relative refractive index difference between the first refractive index and the second refractive index is not less than 0.04 and does not exceed 0.13. The height of the pillars with respect to the thickness of the photonic crystal layer is not less than 0.10t and does not exceed 0.07t.

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

Abstract: A 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 laser device including a gain medium that has a gain, a waveguide for propagating an electromagnetic wave, and a resonant structure comprised of the waveguide. The gain medium extends in the propagation direction, and is sandwiched, at the top and bottom surfaces in the thickness direction thereof, between a first cladding and a second cladding of negative dielectric constant media. The gain medium is provided with a lateral structure adjacent to at least one of the side surfaces thereof in the width direction perpendicular to the propagation direction and the thickness direction. The lateral structure includes a positive dielectric constant medium which is sandwiched, at its top and bottom surfaces in the thickness direction thereof, between the negative dielectric constant media. The waveguide is comprised of the gain medium, the lateral structure, the first cladding and the second cladding.

Abstract: A light-emitting semiconductor component which contains a sequence of semiconductor layers (2) with an area of p-doped semiconductor layers (4) and n-doped semiconductor layers (3) between which a first pn junction (5a, 5b) is formed. The pn junction (5a, 5b) is subdivided into a light-emitting section (7) and a protective-diode section (8) in a lateral direction by means of an insulating section (6). An n-doped layer (9), which forms a second pn junction (10) which acts as a protective diode along with the p-doped area (4), is applied to the p-doped area (4) in the area of the protective-diode section (8), the first pn junction (5b) in the protective-diode section (8) having a larger area than the first pn junction (5a) in the light-emitting section (7). The protective-diode section (8) protects the light-emitting semiconductor component from voltage pulses due to electrostatic discharges (ESD).

Abstract: A vertical cavity surface emitting laser capable of efficiently injecting carries into an active region directly under a photonic crystal mirror is provided. The vertical cavity surface emitting laser includes a first reflective mirror 102 constituting a lower mirror, a second reflective mirror 112 constituting an upper mirror, and an active layer 106 provided between the reflective mirrors on a substrate 100. The second reflective mirror 112 includes a periodic refractive index structure periodically arranged in a plane parallel to a surface of the substrate, which structure is composed of a first medium 1100 having conductivity and a second medium 1102 having a refractive index lower than that of the first medium 1100. A layer structure by a third medium 1104 having a refractive index lower than that of the first medium 1100 is embedded in the first medium 1100 on the lower side of the periodic refractive index structure.

Abstract: A DFB laser device which can reduce influence of reflected return light and improve output characteristics and can provide a small-sized and inexpensive optical module when mounted on the optical module. The GC-DFB laser device (10) includes a semiconductor substrate (100), a waveguide layer (104) and an active layer (106) formed on one surface side of the semiconductor substrate, and a diffraction grating structure (102) which is formed on one surface of the waveguide layer and has a gain periodically varying in an optical waveguiding direction; wherein the active layer is disposed so as to adjoin the waveguide layer, a band gap wavelength of the waveguide layer is within ±0.1 ?m of an oscillation wavelength of the active layer, a thickness of the waveguide layer is in a range of 5 to 30 nm, and a width of the active layer is in a range of 0.7 to 1.0 ?m.

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

Abstract: A surface emitting laser device can further improve the light emission efficiency thereof to enlarge the degree of freedom of the device. The surface emitting laser device includes an active layer 103, a photonic crystal layer disposed to be adjacent to the active layer, an electrode 108 disposed on the photonic crystal layer, and a plurality of light emitting regions regulated by the electrode. The photonic crystal layer is configured to include a first photonic crystal region 104 disposed just under the electrode, and having a periodic refractive index structure for resonance of light within a plane, and a second photonic crystal region 105 disposed just under the light emitting region, and having a periodic refractive index structure for emitting light in a direction perpendicular to the plane.

Abstract: A surface-emission laser diode comprises a cavity region over a semiconductor substrate and includes an active layer containing at least one quantum well active layer producing a laser light and a barrier layer, a spacer layer is provided in the vicinity of the active layer and formed of at least one material, an upper and lower reflectors are provided at a top part and a bottom part of the cavity region, the cavity region and the upper and lower reflectors form a mesa structure over the semiconductor substrate, the upper and lower reflectors being formed of a semiconductor distributed Bragg reflector having a periodic change of refractive index and reflecting incident light by interference of optical waves, at least a part of the semiconductor distributed Bragg reflector is formed of a layer of small refractive index of AlxGa1-xAs (0<x?1) and a layer of large refractive index of AlyGa1-yAs (0?y<x?1), the lower reflector is formed of a first lower reflector having a low-refractive index layer of AlAs an

Abstract: A multi-section semiconductor laser diode is disclosed. The laser diode includes a complex-coupled DFB laser section that includes a complex-coupled grating and an active structure for controlling the intensity of oscillating laser light, to oscillate laser light in a single mode, and an external cavity including a phase control section and an amplifier section, the phase control section having a passive waveguide that controls a phase variation of feedback laser light, the amplification section having an active structure that controls the strength of the feedback laser light. Currents are separately provided to the three sections to generate optical pulses with tuning range of tens of GHz. Applications include the clock recovery in the 3R regeneration of the optical communication.

Abstract: A semiconductor device is provided that includes an optical feedback structure that is monolithically integrated with a VCSEL device and which extends the speed of the VCSEL device beyond the speed to which it would otherwise be limited due to relaxation oscillation. The optical feedback structure does not rely on light emissions from the VCSEL substrate material to produce optical feedback. Consequently, extension of the bandwidth of the semiconductor device through the use of optical feedback is not limited by the absorption threshold wavelength of the substrate material. Furthermore, because the optical feedback structure does not include the substrate, the ability to use optical feedback to extend the bandwidth of the device is independent of the precision with which the substrate thickness can be controlled.

Abstract: A semiconductor laser includes a first optical confinement layer, a plurality of first quantum wires and buried semiconductor regions disposed on a first area, a plurality of second quantum wires and buried semiconductor regions disposed on a second area, an active layer disposed on a third area, and a second optical confinement layer. The plurality of first quantum wires and the buried semiconductor regions constitute a first distributed Bragg reflector, and the plurality of second quantum wires and the buried semiconductor regions constitute a second distributed Bragg reflector. The third area is disposed between the first area and the second area. The buried semiconductor regions have a refractive index different from the average refractive index of the first quantum wires and the average refractive index of the second quantum wires. These distributed Bragg reflectors form a DBR laser having a cavity length defined by the length of the active layer.

Abstract: The present invention provides a surface-emission type semiconductor laser wherein an effective length of a cavity is reduced, thereby enabling to realize a higher-speed direct modulation. In the surface-emission type semiconductor laser according to the present invention, when supposing the optical path length (L) of a resonator part relative to a lasing wavelength ?0 to be given as 0.9×?0?L?1.1×?0, and denoting the refractive indexes of a high refractive index layer and a low refractive index layer of a dielectric DBR by nH1 and nL1; the average refractive index within an optical path length ?0/4 in the semiconductor in contact with the dielectric DBR by nS1; and the refractive indexes of the high refractive index layer and the low refractive index layer of a semiconductor DBR by nH2 and nL2, respective materials to be used are selected so as to satisfy the following conditions (1) and (2): nH1>f(nS1)nL12+g(nS1)nL1+h(nS1),??(1) where f(nS1)=0.0266 nS12?0.2407 nS1+0.6347; g(nS1)=?0.0508 nS12+0.

Abstract: A laser amplification structure comprising an active medium and at least two electrodes disposed on either side of the active medium, the active medium comprising a first layer of a silicon oxide doped with rare earth ions, wherein the first silicon layer is co-doped with silicon nanograins and rare earth ions.

Abstract: An optical semiconductor device includes an optical semiconductor element, a metal pattern and at least one thermal conductive material. The optical semiconductor element has a first optical waveguide region and a second optical waveguide region. The second optical waveguide region is optically coupled to the first optical waveguide region and has a heater for changing a refractive index of the second optical waveguide region. The metal pattern is provided on an area to be thermally coupled to a temperature control device. The thermal conductive material couples the metal pattern with an upper face of the first optical waveguide region of the optical semiconductor element. The thermal conductive material is electrically separated from the first optical waveguide region.

Abstract: An optical semiconductor device includes a semiconductor laser, a first optical waveguide, an optical coupler for branching light guided from the semiconductor laser through the first optical waveguide into two lights, two second optical waveguides, diffraction gratings provided individually on the two second optical waveguides, and an optical detector for detecting light guided through one of the two diffraction gratings, and the components are provided on the same substrate. The optical semiconductor device is configured such that reflection returning lights from the diffraction gratings side to the semiconductor laser side interfere with each other and thereby extinguish each other at the optical coupler and the phases of the reflection returning lights from the diffraction gratings side are displaced from each other by ? at the optical coupler portion.

Abstract: A VCSEL includes a GaAs substrate; a first semiconductor distributed Bragg reflector (DBR) disposed on the GaAs substrate and including a first part and a second part on the first part; a semiconductor mesa disposed on the first semiconductor DBR and including an active layer; and a second DBR on the semiconductor mesa. The first part is composed of an undoped semiconductor material. The second part includes third III-V compound semiconductor layers composed of a material containing indium and gallium as the group III element and phosphorus as the group V element and fourth III-V compound semiconductor layers composed of a material containing gallium as the group III element and arsenic as the group V element. The third III-V compound semiconductor layers and the fourth III-V compound semiconductor layers are doped with an n-type impurity.

Abstract: Various methods and apparatuses are described in which an array of optical gain mediums capable of lasing are contained in a single integral unit. The array may contain four or more optical gain mediums capable of lasing. Each optical gain medium capable of lasing supplies a separate optical signal containing a band of wavelengths different than the other optical gain mediums capable of lasing in the array to a first multiplexer/demultiplexer. A connection for an output fiber exists to route an optical signal to and from a passive optical network.

Abstract: A semiconductor device is provided that includes an optical feedback structure that is monolithically integrated with a VCSEL device and which extends the speed of the VCSEL device beyond the speed to which it would otherwise be limited due to relaxation oscillation. The optical feedback structure does not rely on light emissions from the VCSEL substrate material to produce optical feedback. Consequently, extension of the bandwidth of the semiconductor device through the use of optical feedback is not limited by the absorption threshold wavelength of the substrate material. Furthermore, because the optical feedback structure does not include the substrate, the ability to use optical feedback to extend the bandwidth of the device is independent of the precision with which the substrate thickness can be controlled.

Abstract: A pumping system for a laser source includes a pump diode that emits a pump beam having a central wavelength that varies with temperature. A selective mirror having a plurality of spectral reflectivity peaks, corresponding to a plurality of predetermined wavelengths, locks the operation of the pump diode onto one of the predetermined wavelengths in accordance with temperature.

Abstract: A semiconductor integrated device includes a plurality of wavelength tunable lasers, provided on a semiconductor substrate, and having oscillation wavelength ranges different from each other. Each of the wavelength tunable lasers includes an optical waveguide including, alternately in an optical axis direction, a gain waveguide portion and a wavelength controlling waveguide portion, and a diffraction grating provided over both the gain waveguide portion and the wavelength controlling waveguide portion. A value obtained by dividing a width of the wavelength controlling waveguide portion by a width of the gain waveguide portion in one of the plurality of wavelength tunable lasers is larger than a value obtained by dividing a width of the wavelength controlling waveguide portion by a width of the gain waveguide portion in a different one of the wavelength tunable lasers, which oscillates on a shorter wavelength side with respect to an oscillation wavelength range of the one wavelength tunable laser.

Abstract: In a surface emitting laser element, on an inclined substrate, a resonator structural body including an active layer, and a lower semiconductor DBR and an upper semiconductor DBR sandwiching the resonator structural body are stacked. A shape of a current passing-through region in an oxide confinement structure of the upper semiconductor DBR is symmetrical to an axis passing through a center of the current passing-through region parallel to an X axis and symmetrical to an axis passing through the center of the current passing-through region parallel to a Y axis, and a thickness of an oxidized layer surrounding the current passing-through region is greater in the +Y direction than in the +X and ?X directions. An opening width of a light outputting section in the X axis direction is smaller than another opening width of the light outputting section in the Y axis direction.

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: Objects are achieved by an optical semiconductor device comprising: a structure 61 including a substrate 50, a diffraction grating 52a, an active layer 54 and a refractive index control layer 60; and an laser element 100 including an electrode 92a for the active layer, an electrode 92b for the refractive index control layer and an electrode 92c for switching, wherein a pre-bias current is previously supplied from the electrode 92a for the active layer to the active layer 54 in a state where a switching current is not supplied from the electrode 92c for switching to the active layer 54, and then while a current Idrive for activation is supplied from the electrode 92a for the active layer to the active layer 54, the laser element 100 is turned on by supplying the switching current Isw from the electrode 92c for switching to a part of the active layer 54, as well as turning off the laser element 100 by halting the supply of the switching current Isw.

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

Abstract: A monolithically-integrated semiconductor optical transmitter that can index tune to any transmission wavelength in a given range, wherein the range is larger than that achievable by the maximum refractive index tuning allowed by the semiconductor material itself (i.e. ??/?>?n/n). In practice, this tuning range is >15 nm. The transmitter includes a Mach-Zehnder (MZ) modulator monolithically integrated with a widely tunable laser and a semiconductor optical amplifier (SOA). By using an interferometric modulation, the transmitter can dynamically control the chirp in the resulting modulated signal over the wide tuning range of the laser.

Abstract: A tunable distributed feedback semiconductor laser includes a substrate; an optical waveguide structure disposed on a main surface of the substrate and including an active layer and a diffraction grating, the optical waveguide structure being divided into a first DFB portion, a wavelength-tuning region, and a second DFB portion in that order; a first electrode for injecting carriers into the active layer in the first DFB portion; a second electrode for injecting carriers into the active layer in the second DFB portion; and a third electrode for supplying a wavelength tuning signal to the wavelength-tuning region. The diffraction grating extends over the first DFB portion, the wavelength-tuning region, and the second DFB portion. An optical confinement factor of the wavelength-tuning region is smaller than that of the first and second DFB portions.

Abstract: An extended cavity surface emitting laser has a first laser die with a first cavity and a first gain element and a second laser die with a second cavity and a second gain element. The first and second gain elements are in series to provide optical gain and optical feedback in an extended optical cavity configuration. The first and second gain elements provide optical gain and optical feedback in a common extended cavity with the first and second gain elements operating serially as a common extended cavity optical mode.

Abstract: A surface-emitting laser array includes a plurality of surface-emitting laser elements. Each surface-emitting laser element includes a first reflection layer formed on a substrate, a resonator formed in contact with the first reflection layer and containing an active layer, and a second reflection layer formed over the first reflection layer and in contact with the resonator. The second reflection layer contains a selective oxidation layer. The first reflection layer contains on the active layer side at least a low refractive index layer having an oxidation rate equivalent to or larger than an oxidation rate of a selective oxidation layer contained in the second reflection layer. The resonator is made of an AlGaInPAs base material containing at least In. A bottom of a mesa structure is located under the selective oxidation layer and over the first reflection layer.

Abstract: In general, a complex-coupled distributed feedback (DFB) semiconductor laser includes a grating formed by grooves through at least a part of an active region of a laser cavity. The complex-coupled DFB laser may be configured with a wavelength monitoring section and may be configured to provide facet power asymmetry. The wavelength monitoring section may include a second-order grating section configured to emit radiation (e.g., vertical radiation) from a side of the DFB laser for monitoring.

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 compact and efficient ultraviolet laser source based on a optically-pumped solid-state or fiber laser that produces near-infrared output light suitable for nonlinear frequency conversion. The infrared laser output is frequency tripled or quadrupled to produce light in the ultraviolet wavelength range (200 nm to 400 nm). The novel technology is the use of highly efficient periodically poled nonlinear crystals, such as stoichiometric and MgO-doped lithium tantalate and lithium niobate. As opposed to conventional frequency-converted UV laser sources, which have high power consumption, high cost, and low efficiency, the laser sources of this invention utilize high efficiency nonlinear conversion provided by periodically poled materials and allow lower-cost architectures without additional focusing lenses, high power pump diodes, etc.

Abstract: Surface emitting laser arrays with intra-cavity harmonic generation are coupled to an optical system that extracts harmonic light in both directions from an intra-cavity nonlinear optical material in such a way that the focusing properties of the light beams are matched.

Abstract: An ultrafast laser system includes a seed laser that provides a signal laser pulse and a fiber-based first chirped reflective Bragg grating that reflects the signal laser pulse propagating along a first path and produce a stretched laser pulse longer than the signal laser pulse. A grating frequency of the first chirped reflective Bragg grating varies along the first path. An amplifier can amplify the stretched laser pulse and output an amplified laser pulse. A second chirped reflective Bragg grating can reflect the amplified laser pulse and produce a compressed laser pulse shorter than the amplified laser pulse. The amplified laser pulse propagates along a second path in the second chirped reflective Bragg grating. A grating frequency of the second chirped reflective Bragg grating varies in an opposite direction along the second path as the grating frequency of the first chirped reflective Bragg grating varies along the first path.

Abstract: In a surface emitting laser element, on a substrate whose normal direction of a principal surface is inclined, a resonator structural body including an active layer, and a lower semiconductor DBR and an upper semiconductor DBR sandwiching the resonator structural body are stacked. A shape of a current passing through region in an oxide confinement structure of the upper semiconductor DBR is symmetrical to an axis passing through a center of the current passing through region parallel to an X axis and symmetrical to an axis passing through the center of the current passing through region parallel to a Y axis, and a length of the current passing through region is greater in the Y axis direction than in the X axis direction. A thickness of an oxidized layer surrounding the current passing through region is greater in the ?Y direction than in the +X and ?X directions.

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 the upper mirror includes a first region in which a plurality of holes are formed and a second region inside the first region in which no hole is formed, the second region is in a circular shape as viewed in a plan view, the circular shape has a radius with which an energy increasing rate in the active layer becomes positive with a lower-order mode and (becomes) negative with a higher-order mode, and the holes have a depth with which the energy increasing rate becomes positive with the lower-order mode, and becomes negative with the higher-order mode.

Abstract: A semiconductor laser has first and second diffractive grating regions. The first diffractive grating region has segments, has a gain, and has first discrete peaks of a reflection spectrum. The second diffractive grating region has segments combined to each other, and has second discrete peaks of a reflection spectrum. Each segment has a diffractive grating and a space region. Pitches of the diffractive grating are substantially equal to each other. A wavelength interval of the second discrete peaks is different from that of the first discrete peaks. A part of a given peak of the first discrete peaks is overlapped with that of the second discrete peaks when a relationship between the given peaks of the first discrete peaks and the second discrete peaks changes.

Abstract: A broadband fiber laser provides a lasing cavity including a reflective mirror and at least one fiber Bragg grating for further providing a lasing signal to resonate and be amplified therein. Alternatively, the wavelength of the fiber laser can be either fixed or tunable by varying the central wavelength of the fiber Bragg grating and/or by adjusting the switching status of an optical switch pair.

Abstract: A vertical external cavity surface emitting laser (VECSEL) in which the full-width at half maximum (FWHM) of laser light is reduced by two etalon filter layers to improve the efficiency of second harmonic (SHG) crystal is provided. The VECSEL includes: a laser chip for generating laser light; a first etalon filter layer formed on the laser chip; a second etalon filter layer that is formed on the first etalon filter layer and has a different refractive index than the first etalon filter layer; a first mirror separated from and disposed obliquely to the laser chip; a second mirror for reflecting the laser light reflected from the first mirror back to the first mirror to form a cavity with the laser chip; and an SHG crystal disposed along an optical path between the first and second mirrors and doubles the frequency of the laser light generated in the laser chip.

Abstract: This surface emitting semiconductor device 1 comprises a first conductivity type semiconductor region, an active layer, a second conductivity type semiconductor layer and current block semiconductor region. The first conductivity type semiconductor region is provided on a surface made of GaAs semiconductor. The active layer is provided on the first conductivity type semiconductor region. The active layer has a side surface. The second conductivity type semiconductor layer is provided on the active layer. The second conductivity type semiconductor layer has a side surface. The current block semiconductor region is provided on the side surface of the active layer and on the side surface of the second conductivity type semiconductor layer. The active layer is made of III-V compound semiconductor including at least nitrogen element as a V group element.

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.