Abstract: A semiconductor laser according to the present invention comprises a ?/2 dielectric film (?:in-medium wavelength of a dielectric film, for example, SiO2, Si3N4, Al2O3, and AlN) in contact with a facet of a resonator; and a first dielectric double layered film disposed on the dielectric film, which includes a first layer of a-Si and a second layer of a material having a refractive index lower than that of a-Si. The first layer has a thickness ¼ of an in-medium wavelength of a-Si, and the second layer has a thickness ¼ of an in-medium wavelength of the second layer. Therefore, it is possible to firmly stack the first dielectric double layered film and form a high reflectance film with high yield.

Abstract: Provided is a semiconductor laser, wherein (?a??w)>15 (nm) and Lt<25 (?m), where ?w is the wavelength of light corresponding to the band gap of the active layer disposed at a position within a distance of 2 ?m from one end surface in a resonator direction, ?a is the wavelength of light corresponding to the band gap of the active layer disposed at a position that is spaced a distance of equal to or more than ( 3/10)L and <( 7/10)L from the one end surface in a resonator direction, “L” is the resonator length, and “Lt” is the length of a transition region provided between the position of the active layer with a band gap corresponding to a light wavelength of ?w+2 (nm) and the position of the active layer with a band gap corresponding to a light wavelength of ?a?2 (nm) in the resonator direction.

Abstract: A nitride semiconductor laser device includes a multilayer structure including a plurality of nitride semiconductor layers including a light emitting layer, the multilayer structure having cavity facets facing each other, and a plurality of protective films made of a dielectric material provided on one of the cavity facets. The protective films include a first protective film, a second protective film and a third protective film. The first protective film contacts the cavity facet and is made of aluminum nitride. The second protective film is provided on a surface opposite to the cavity facet of the first protective film and is made of a material different from that of the first protective film. The third protective film is provided on a surface opposite to the first protective film of the second protective film and is made of the same material as that of the first protective film.

Abstract: The disclosure is directed to a thin-film for use in below 300 nm laser systems that can be applied to a variety of substrate types. The thin film consists of a blocking layer of a selected material and a matching structure, the matching structure consisting of 1-7 layers of a selected material. The blocking layer serves to minimize or eliminate the transmission of below 300 nm laser light into an adhesive that is used to bond the substrate to a holder. The matching layer(s) minimize internal reflectance of below 300 nm laser light from the blocking layer back into the substrate.

Abstract: A semiconductor laser is embodied as a surface emitting thin-film semiconductor laser (2) with a semiconductor body (4). The semiconductor body (4) comprises a first and a second planar surface (12, 14). The semiconductor body (4) comprises between the planar surfaces at least one active layer (10) for generating radiation. The semiconductor body (4) has, for coupling out the radiation from the active layer (10) toward the first planar surface (12), at least one first mirror area (26) inclined with respect to the active layer (10).

Abstract: Provided are a group-III nitride semiconductor laser device with a laser cavity to enable a low threshold current on a semipolar surface of a hexagonal group-III nitride, and a method for fabricating the group-III nitride semiconductor laser device on a stable basis. Notches, e.g., notch 113a and others, are formed at four respective corners of a first surface 13a located on the anode side of a group-III nitride semiconductor laser device 11. The notch 113a or the like is a part of a scribed groove provided for separation of the device 11. The scribed grooves are formed with a laser scriber and the shape of the scribed grooves is adjusted by controlling the laser scriber. For example, a ratio of the depth of the notch 113a or the like to the thickness of the group-III nitride semiconductor laser device 11 is not less than 0.05 and not more than 0.

Abstract: This semiconductor laser element includes a semiconductor element layer including an active layer and having an emitting side cavity facet and a reflecting side cavity facet, and a facet coating film on a surface of the emitting side cavity facet. The facet coating film includes a first dielectric layer controlling a reflectance of the emitting side cavity facet and a second dielectric layer. A thickness of the second dielectric layer is set to a thickness defined by m×?/(2×n) (m is an integer), where a wavelength of a laser beam emitted from the active layer is ?. and a refractive index of the second dielectric layer is n, and is larger than a thickness of the first dielectric layer and at least 1 ?m.

Abstract: This semiconductor laser element includes a semiconductor element layer including an active layer and having an emitting side cavity facet and a reflecting side cavity facet, and a facet coating film on a surface of the emitting side cavity facet. The facet coating film includes a photocatalytic layer arranged on an outermost surface of the facet coating film and a dielectric layer arranged between the photocatalytic layer and the emitting side cavity facet. A thickness of the dielectric layer is set to a thickness defined by m×?/(2×n) (m is an integer), where a wavelength of a laser beam emitted from the active layer is ? and a refractive index of the dielectric layer is n, and at least 1 ?m.

Abstract: In an optical pulse generating apparatus including a metal layer having an incident/reflective surface adapted to receive incident light and output its reflective light as an optical pulse signal, a dielectric layer formed on an opposite surface of the metal layer opposing the incident/reflective surface, and a dielectric layer exciting unit for exciting the dielectric layer on a time basis, the incident light exciting surface plasmon resonance light in the metal layer while the dielectric layer is excited on a time basis, so that an extinction coefficient of the dielectric layer is made negative.

Abstract: A nitride semiconductor device includes a multilayer semiconductor structure made of a group III nitride semiconductor and having a light-emitting facet, and a first coating film formed to cover the light-emitting facet of the multilayer semiconductor structure. The first coating film is a crystalline film made of a nitride containing aluminum. The crystalline film is composed of a group of single domains, and the single domain is comprised of a group of grains whose crystal orientation planes have a same inclination angle and a same rotation angle. A length of a boundary between the domains per unit area is 7 ?m?1 or less.

Abstract: A process for fabricating lasers capable of emitting blue light wherein a GaN wafer is etched to form laser waveguides and mirrors using a temperature of over 500° C. and an ion beam in excess of 500 V in CAIBE.

Abstract: A nitride semiconductor laser element includes a nitride semiconductor layer of a first conduction type, an active layer, and a nitride semiconductor layer of a second conduction type that is different from the first conduction type are laminated in that order, a cavity end face formed by the nitride semiconductor layers, and a protective film formed on the cavity end face. The nitride semiconductor layers of the first and second conduction types have layers containing Al, and the active layer has layer containing In. The protective film has a region in which an axial orientation of crystals is the same as that of the cavity end face on the nitride semiconductor layers of the first and second conduction types, and has another region in which an axial orientation of crystals is different from that of the cavity end face on the active layer.

Abstract: Disclosed is a white light emitting device including a semiconductor light emitting element configured to emit near ultraviolet light having a peak wavelength ranging from 380 to 410 nm, a first phosphor layer and a second phosphor layer. The first phosphor layer contains a blue-emitting phosphor configured to emit blue light by the near ultraviolet light, and a red-emitting phosphor activated by trivalent europium and configured to emit red light by the near ultraviolet light. The second phosphor layer contains a green-emitting phosphor configured to emit green light by the near ultraviolet light. The semiconductor light emitting element, the first phosphor layer and the second phosphor layer are laminated in this order to emit white light.

Abstract: A semiconductor laser according to the present invention comprises a ?/2 dielectric film (?:in-medium wavelength of a dielectric film, for example, SiO2, Si3N4, Al2O3, and AIN) in contact with an facet of a resonator; and a first dielectric double layered film disposed on the dielectric film, which includes a first layer of a-Si and a second layer of a material having a refractive index lower than that of a-Si. The first layer has a thickness) ¼ of a in-medium wavelength of a-Si, and the second layer has a thickness ¼ of a in-medium wavelength of the second layer. Therefore, it is possible to firmly stack the first dielectric double layered film and form a high reflectance film with high yield.

Abstract: An etched-facet single lateral mode semiconductor photonic device is fabricated by depositing an anti reflective coating on the etched facet, and depositing a reflectivity modifying coating in a spatially controlled manner to modify the spatial performance of the emitted beam.

Abstract: A semiconductor laser device capable of improving the reliability of the laser device is obtained. This semiconductor laser device (1000) includes a semiconductor element layer (20) having a light emitting layer (25), a first cavity facet (1) formed on an end portion on a light emitting side of a region of the semiconductor element layer including the light emitting layer, a first insulating film (40) in which a first nitride film (41), a first intermediate film including a first oxide film (42) and a second nitride film (43) are formed on the first cavity facet in this order from the side of the first cavity facet and a second insulating film (51), formed on the first insulating film, including a second oxide film (51).

Abstract: A device having a light cavity includes, at one end, a plasmonic reflector having a grating surface for coupling incoming light into traverse plasmon waves and for coupling the traverse plasmon wave into broaden light, the surface serving to redistribute light within the cavity, the reflector being well suited for use in laser diodes for redistributing filamental cavity laser light into spatially broaden cavity laser light for translating multimodal laser light into unimodal laser light for improved reliability and uniform laser beam creation.

Abstract: One facet and the other facet of a nitride based semiconductor laser device are respectively composed of a cleavage plane of (0001) and a cleavage plane of (000 1). Thus, the one facet and the other facet are respectively a Ga polar plane and an N polar plane. A portion of the one facet and a portion of the other facet, which are positioned in an optical waveguide, constitute a pair of cavity facets. A first protective film including oxygen as a constituent element is formed on the one facet. A second protective film including nitrogen as a constituent element is formed on the other facet.

Abstract: A laser light source comprises, in particular, a semiconductor layer sequence (10) having an active region (45) and a radiation coupling-out area (12) having a first partial region (121) and a second partial region (122) different than the latter, and a filter structure (5), wherein the active region (45) generates, during operation, coherent first electromagnetic radiation (51) having a first wavelength range and incoherent second electromagnetic radiation (52) having a second wavelength range, the coherent first electromagnetic radiation (51) is emitted by the first partial region (121) along an emission direction (90), the incoherent second electromagnetic radiation (52) is emitted by the first partial region (121) and by the second partial region (122), the second wavelength range comprises the first wavelength range, and the filter structure (5) at least partly attenuates the incoherent second electromagnetic radiation (52) emitted by the active region along the emission direction (90).

Abstract: One facet of a nitride based semiconductor laser device is composed of a cleavage plane of (0001), and the other facet thereof is composed of a cleavage plane of (000 1). Thus, the one facet and the other facet are respectively a Ga polar plane and an N polar plane. A portion of the one facet and a portion of the other facet, which are positioned in an optical waveguide, constitute a pair of cavity facets. A first protective film including nitrogen as a constituent element is formed on the one facet. A second protective film including oxygen as a constituent element is formed on the other facet.

Abstract: According to one embodiment, a semiconductor laser device includes stacked layers and a light output layer. The stacked layers include an active layer. The light output layer is provided in contact with a light output end face of an optical cavity made of the stacked layers. The light output layer includes a dielectric layer having a non-amorphous film, and a conductor portion provided at least one of on a surface of the dielectric layer and inside the dielectric layer.

Abstract: Disclosed are a nitride semiconductor laser element including a light emitting portion made of a nitride semiconductor, and an external-cavity semiconductor laser device using it. In the nitride semiconductor laser element, a coat film made of silicon oxynitride is formed on the light emitting portion, and the reflectance of the coat film to feedback light of laser light emitted from the light emitting portion is 0.5% or less.

Abstract: It is an object of the invention to provide a simple setup of a waveguide laser which allows to control the emission of specific laser wavelengths in a laser material having laser transitions of similar wavelengths. For this purpose a core (4) forming a gain medium is provided with a cladding (6) which introduces losses to an undesired laser transition but is transparent to the light of a desired laser transition. A second cladding (8) is provided for guiding the laser radiation. Pr: ZBLAN with a Tb: doped cladding may be used. Instead of the absorbing cladding (6) a photonic crystal (20) may be used. The laser is end-pumped by a laser diode (14).

Abstract: An etched-facet single lateral mode semiconductor photonic device is fabricated by depositing an anti reflective coating on the etched facet, and depositing a reflectivity modifying coating in a spatially controlled manner to modify the spatial performance of the emitted beam.

Abstract: The disclosure is directed to a thin-film for use in below 300 nm laser systems that can be applied to a variety of substrate types. The thin film consists of a blocking layer of a selected material and a matching structure, the matching structure consisting of 1-7 layers of a selected material. The blocking layer serves to minimize or eliminate the transmission of below 300 nm laser light into an adhesive that is used to bond the substrate to a holder. The matching layer(s) minimize internal reflectance of below 300 nm laser light from the blocking layer back into the substrate.

Abstract: Semiconductor laser elements are formed on a common substrate. Au plating is formed on principal surfaces of the semiconductor laser elements. The semiconductor laser elements are mounted on a package with solder applied to the Au plating. Areas opposed to each other across a light-emitting area of each semiconductor laser element are designated first and second areas. Average thickness of the Au plating is different in the first and second areas of each semiconductor laser element.

Abstract: A quantum cascade laser amplifier (12) having an active zone (20) includes a stack of raw layers of semi-conductor materials formed in an epitaxial manner on a substrate layer (16) of indium. phosphide (InP) or gallium arsenide (GaAs) bearing the active zone (20), and a vertical anti-reflection coating (34) that covers an outlet face (28) of the laser radiation made of materials having given refraction indices and a predetermined thickness so that the entire laser radiation can flow through the outlet face. The anti-reflection coating (34) includes a first layer (36) having a first predetermined retraction index (n1) lower than the predetermined refraction index (nD), and at least a second layer (38) having a second refraction index (n2) higher than the predetermined refraction index (nD), wherein the first layer (36) of the anti-reflection coating (34) is made of yttrium fluoride (YF3).

Abstract: A coating film is provided on an end surface of a semiconductor photonic element including an active layer through which light propagates. The coating film has a two-layer structure including a first layer film and a second layer film arranged in a stacked relation. The thicknesses of the first and second layer films are determined so that the value of the amplitude reflectivity of the coating film is equal to an imaginary number.

Abstract: A semiconductor laser device includes a chip obtained from a substrate and a semiconductor multi-layer formed on the substrate. The semiconductor multi-layer is formed from a plurality of semiconductor layers of a semiconductor material having a hexagonal structure, and includes a stripe-shaped wave guide portion. The chip includes two chip end facets that extend in a direction crossing an extending direction of the wave guide portion. Each of regions on both sides of the wave guide portion in at least one of the chip end facets has a notch portion formed by notching a part of the chip, and the notch portion exposes a first wall surface connecting to the chip end facet and a second wall surface connecting to the chip side facet. An angle between an extending direction of the first wall surface in at least one of the two notch portions and an extending direction of the cleavage facet is in a range of about 10 degrees to about 40 degrees.

Abstract: One facet and the other facet of a nitride based semiconductor laser device are respectively composed of a cleavage plane of (0001) and a cleavage plane of (000 1). Thus, the one facet and the other facet are respectively a Ga polar plane and an N polar plane. A portion of the one facet and a portion of the other facet, which are positioned in an optical waveguide, constitute a pair of cavity facets. A first protective film including oxygen as a constituent element is formed on the one facet. A second protective film including nitrogen as a constituent element is formed on the other facet.

Abstract: A laser diode capable of effectively inhibiting effects of feedback light is provided. A laser diode includes a substrate, and a laminated structure including a first conductive semiconductor layer, an active layer having a light emitting region, and a second conductive semiconductor layer having a projecting part on the surface thereof, on the substrate, wherein a feedback light inhibition part is provided on a main-emitting-side end face, and effects of feedback light in the vicinity of lateral boundaries of the light emitting region are inhibited by the feedback light inhibition part.

Abstract: A nitride-based semiconductor laser device includes a nitride-based semiconductor layer formed on a main surface of a substrate and having an emission layer, wherein the nitride-based semiconductor layer includes a first side surface formed by a (000-1) plane and a second side surface inclined with respect to the first side surface, and a ridge having an optical waveguide extending perpendicular to a [0001] direction in an in-plane direction of the main surface of the substrate is formed by a region held between the first side surface and the second side surface.

Abstract: An adhesion layer of a hexagonal crystal is laid on a facet an optical resonator of a nitride semiconductor laser bar having a nitride-based III-V group compound semiconductor layer, and a facet coat is laid on the adhesion layer. In this way, a structure in which the facet coat is laid on the adhesion layer is obtained.

Abstract: A nitride semiconductor laser chip is provided that offers sufficient reliability even at high output. The nitride semiconductor laser chip has a nitride semiconductor layer formed on a substrate, a resonator facet formed on the nitride semiconductor layer, and a coating film formed on the resonator facet and containing Ar. The coating film has, in a region contiguous with the resonator facet and in the vicinity thereof, a low-Ar region with a low Ar content and, on the side of this low-Ar region opposite from the resonator facet, a high-Ar region with a higher Ar content than the low-Ar region.

Abstract: On a first region that is a part of one main face of a semiconductor substrate 1, a first semiconductor laser structure 10 is formed so as to have a first lower cladding layer 3, a first active layer 4 with a first quantum well structure and first upper cladding layers 5, 7, which are layered in this order from the semiconductor substrate side, thereby forming a first resonator. On a second region that is different from the first region, a second semiconductor laser structure 20 is formed so as to have a second lower cladding layer 13, a second active layer 14 with a second quantum well structure and a second upper cladding layer 15, 17, which are layered in this order, thereby forming a second resonator. End face coating films 31, 32 are formed on facets of the first and the second resonators, and a nitrogen-containing layer 30 is formed between the facets of the first and the second resonators and the facet coating film.

Abstract: A semiconductor laser device includes: a substrate of a first conductivity type; a laminated body of a nitride semiconductor provided on the substrate and including at least an active layer and a cladding layer, the cladding layer being of a second conductivity type and having a ridge-shaped waveguide; a first film provided on one end surface of an optical resonator composed of the laminated body, the first film having a reflectance of 40% or more and 60% or less; and a second film provided on the other end surface of the optical resonator and having a higher reflectance than the first film. The optical resonator has a length of 400 ?m or less. The one end surface serves as a light emitting surface.

Abstract: This semiconductor laser device includes a semiconductor element layer having an active layer and a cavity facet and a facet coating film arranged on the cavity facet, while the facet coating film includes an oxide film made of hafnium silicate (HfSiO) or hafnium aluminate (HfAlO), and the facet coating film further has a nitrogen-containing film, in contact with the cavity facet, between the cavity facet and the oxide film.

Abstract: A method of avoiding device failure caused by facet heating is described. The method is particularly applicable to a semiconductor laser. In the method, a semiconductor laser facet including GaAsN is hydrogenated such that the bandgap within the facet is greater than the bandgap in the active region of the InGaAsN laser. The increased bandgap reduces absorption of light in the facet and the associated heating that results.

Abstract: A semiconductor laser device 100 having a ridge stripe structure comprises: an n-type clad layer 105 having a protrusion; and an n-type current block layer 107 covering the clad layer, except the upper surface of the protrusion. When the width of the upper surface is W, the distance between front and rear cleavage planes is L, the width of the upper surface at the front cleavage plane is Wf, and the width of the upper surface at the rear cleavage is Wr. In a range where a distance from the front cleavage plane is shorter than or equal to L/2, an area Sc of the upper surface is in a range of L/8×(3Wf+Wr)<Sc?L/2×Wf, and W in an arbitrary position in the range is in a range of ½(Wf+Wr)<W?Wf.

Abstract: An active layer (18) is formed over a semiconductor substrate having a pair of facets (15A, 15B) mutually facing opposite directions. An upper cladding layer (19) is formed on the active layer, having a refractive index lower than that of the active layer. A diffraction grating (25) is disposed in the upper cladding layer on both sides of a distributed feedback region in a waveguide region (22), the waveguide region extending from one facet to the other of the semiconductor substrate. End regions (22B) are defined at both ends of the waveguide region and the distributed feedback region (22A) is disposed between the end regions. Low refractive index regions (26) are disposed in the upper cladding layer on both sides of each of the end regions of the waveguide region, the low refractive index regions having a refractive index lower than that of the upper cladding layer.

Abstract: A method and structure for producing lasers having good optical wavefront characteristics, such as are needed for optical storage includes providing a laser wherein an output beam emerging from the laser front facet is essentially unobstructed by the edges of the semiconductor chip in order to prevent detrimental beam distortions. The semiconductor laser structure is epitaxially grown on a substrate with at least a lower cladding layer, an active layer, an upper cladding layer, and a contact layer. Dry etching through a lithographically defined mask produces a laser mesa of length lc and width bm. Another sequence of lithography and etching is used to form a ridge structure with width won top of the mesa. The etching step also forming mirrors, or facets, on the ends of the laser waveguide structures. The length ls and width bs of the chip can be selected as convenient values equal to or longer than the waveguide length lc and mesa width bm, respectively.

Abstract: A semiconductor light-emitting device includes a light generation unit generating light with an oscillation wavelength ?, a light outgoing facet from which light generated at the light generation unit emerges, a light reflecting facet at which light generated at the light generation unit is reflected, and a high reflection film at the light reflecting facet and made of a dielectric multilayered film of at least three layers. The high reflection film includes a first layer which is in contact with the light reflection facet, is constituted of Al2O3, and has a thickness smaller than ?/4n, wherein n is the refractive index of Al2O3, a second layer which is in contact with the first layer, and a third layer which is in contact with the second layer and has a refractive index different from the refractive index of the second layer.

Abstract: An adhesion layer of a hexagonal crystal is laid on a facet an optical resonator of a nitride semiconductor laser bar having a nitride-based III-V group compound semiconductor layer, and a facet coat is laid on the adhesion layer. In this way, a structure in which the facet coat is laid on the adhesion layer is obtained.

Abstract: A semiconductor device includes an optical semiconductor element, a package including a base made of a metal for mounting the optical semiconductor element, and a cap for encapsulating the optical semiconductor element and a gas by covering the package and the optical semiconductor element. The gas encapsulated with the package has an oxygen concentration not less than 15% and less than 30% and has a dew-point not less than ?15° C. and not more than ?5° C.

Abstract: A semiconductor laser element realizes a high COD light output in broader range of reflection factor at a facet with high reliability. A semiconductor laser element has a multi-layered reflection film formed on at least one end facet of a resonator. An optical path length of each layer of said multi-layered reflection film is determined by (2m?1)·?/4, where ? is oscillation wavelength, and m is positive integer). A high-refractive-index layer and a low-refractive-index layer are alternately stacked starting from a first layer adjacent to said semiconductor.

Abstract: The present invention pertains to a composite slab laser gain medium with an undoped core and at least one doped gain medium section disposed on at least one side of that core. The gain medium is constructed so as to mitigate the effects of thermal and mechanical stresses within it and also allow for impingement cooling of the doped gain medium section.

Abstract: A nitride-based semiconductor light-emitting diode capable of suppressing complication of a manufacturing process while improving light extraction efficiency from a light-emitting layer and further improving flatness of a semiconductor layer is obtained. This nitride-based semiconductor light-emitting diode (30) includes a substrate (11) formed with a recess portion (21) on a main surface and a nitride-based semiconductor layer (12) having a light-emitting layer (14) on the main surface and including a first side surface (12a) having a (000-1) plane formed to start from a first inner side surface (21a) of the recess portion and a second side surface (12b) formed at a region opposite to the first side surface with the light-emitting layer therebetween to start from a second inner side surface (21b) of the recess portion on the main surface.

Abstract: In an edge emitting semiconductor laser comprising an active layer (3) that generates laser radiation (13) and is embedded into a first waveguide layer (1), wherein the first waveguide layer (1) is arranged between a first cladding layer (4) and a second cladding layer (5) and is delimited by side facets (9) of the semiconductor laser in a lateral direction, a second waveguide layer (2), into which no active layer is embedded, adjoins the second cladding layer (5), the second waveguide layer (2) being optically coupled to the first waveguide layer (1) at least in partial regions (10, 11), and a third cladding layer (6) is arranged at a side of the second waveguide layer (2) that is remote from the first waveguide layer (1).

Abstract: A semiconductor laser according to the present invention comprises a ?/2 dielectric film (?: in-medium wavelength of a dielectric film, for example, SiO2, Si3N4, Al2O3, and AlN) in contact with an facet of a resonator; and a first dielectric double layered film disposed on the dielectric film, which includes a first layer of a-Si and a second layer of a material having a refractive index lower than that of a-Si. The first layer has a thickness ¼ of a in-medium wavelength of a-Si, and the second layer has a thickness ¼ of a in-medium wavelength of the second layer. Therefore, it is possible to firmly stack the first dielectric double layered film and form a high reflectance film with high yield.

Abstract: A nitride semiconductor laser element comprises; a nitride semiconductor layer that includes a first nitride semiconductor layer, an active layer, and a second nitride semiconductor layer, and that has a cavity with end faces, and a first protective film that is in contact with at least one end face of the cavity, wherein the first protective film has a film structure in which bright and dark parts comprising a region in contact with the active layer and a region in contact with the first and second nitride semiconductor layers are observed under scanning transmission electron microscopy, or the first protective film has a film structure in which the crystallinity at a portion adjacent to the active layer is different from that at portions adjacent to the first and second nitride semiconductor layers.