Crystal Orientation Patents (Class 372/44.011)
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Patent number: 8218595Abstract: A GaN edge emitting laser is provided comprising a semi-polar GaN substrate, an active region, an N-side waveguiding layer, a P-side waveguiding layer, an N-type cladding layer, and a P-type cladding layer. The GaN substrate defines a 20 21 crystal growth plane and a glide plane. The N-side and P-side waveguiding layers comprise a GaInN/GaN or GaInN/GaInN superlattice (SL) waveguiding layers. The superlattice layers of the N-side and P-side SL waveguiding layers define respective layer thicknesses that are optimized for waveguide planarity, the layer thicknesses being between approximately 1 nm and approximately 5 nm. In accordance with another embodiment of the present disclosure, planarization can be enhanced by ensuring that the N-side and P-side GaN-based waveguiding layers are grown at a growth rate that exceeds approximately 0.09 nm/s, regardless of whether the N-side and P-side GaN-based waveguiding layers are provided as a GaInN/GaN or GaInN/GaInN SL or as bulk waveguiding layers.Type: GrantFiled: May 28, 2010Date of Patent: July 10, 2012Assignee: Corning IncorporatedInventor: Rajaram Bhat
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Patent number: 8189639Abstract: A GaN-based edge emitting laser is provided comprising a semi-polar GaN substrate, an active region, an N-side waveguiding layer, a P-side waveguiding layer, an N-type cladding layer, and a P-type cladding layer. The GaN substrate is characterized by a threading dislocation density on the order of approximately 1×106/cm2. The strain-thickness product of the N-side waveguiding layer exceeds its strain relaxation critical value. In addition, the cumulative strain-thickness product of the active region calculated for the growth on a the relaxed N-side waveguiding layer is less than its strain relaxation critical value. As a result, the N-side interface between the N-type cladding layer and the N-side waveguiding layer comprises a set of N-side misfit dislocations and the P-side interface between the P-type cladding layer and the P-side waveguiding layer comprises a set of P-side misfit dislocations. Additional embodiments are disclosed and claimed.Type: GrantFiled: May 28, 2010Date of Patent: May 29, 2012Assignee: Corning IncorporatedInventors: Rajaram Bhat, Dmitry Sizov
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Patent number: 8189633Abstract: A polycrystalline transparent ceramic article including lutetium is presented. The article includes an oxide with a formula of ABO3, having type A lattice sites and type B lattice sites. The lattice site A may further comprise a plurality of elements, in addition to lutetium. Type B lattice site includes aluminum. An imaging device, a laser assembly, and a scintillator including the lutetium-based article is provided. A method of making the above article is also provided.Type: GrantFiled: January 21, 2010Date of Patent: May 29, 2012Assignee: General Electric CompanyInventors: Kalaga Murali Krishna, Venkat Subramaniam Venkataramani, Mohan Manoharan
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Patent number: 8139619Abstract: 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.Type: GrantFiled: August 12, 2011Date of Patent: March 20, 2012Assignee: Sumitomo Electric Industries, Ltd.Inventors: Shimpei Takagi, Yusuke Yoshizumi, Koji Katayama, Masaki Ueno, Takatoshi Ikegami
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Publication number: 20120063481Abstract: A laser structure is provided in which an influence caused by a concave-convex structure on laser characteristics is reduced when the Epitaxial Lateral Overgrowth (ELO) technique is applied to a photonic-crystal surface emitting laser. The laser structure includes a first layer, a second layer, a mask structure, a fourth layer, and a photonic crystal. An optical film thickness of the mask structure is not an integer multiple of a half of an oscillation wavelength ?, and reflectivity taken when laser light enters a multilayer structure including the first layer, the second layer, the mask structure, and the fourth layer from the fourth layer side is lower than reflectivity at an interface between the second layer and the first layer.Type: ApplicationFiled: September 12, 2011Publication date: March 15, 2012Applicant: CANON KABUSHIKI KAISHAInventor: Yasuhiro Nagatomo
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Patent number: 8111725Abstract: A disclosed surface-emitting laser includes a substrate and multiple semiconductor layers stacked on the substrate. A normal of the principal plane of the substrate is inclined with respect to one of crystal orientations <1 0 0> toward one of crystal orientations <1 1 1>. The semiconductor layers include a resonator structure including an active layer; and a semiconductor multilayer mirror stacked on the resonator structure. The semiconductor multilayer mirror includes a confined structure where a current passage area is surrounded by an oxidized area including at least an oxide generated by oxidation of a part of a selective oxidation layer containing aluminum. A strain field caused by the oxidation is present at least in a part of the vicinity of the oxidized area. In the strain field, the amount of strain in a first axis direction is different from the amount of strain in a second axis direction.Type: GrantFiled: May 12, 2009Date of Patent: February 7, 2012Assignee: Ricoh Company, Ltd.Inventors: Toshihiro Ishii, Kengo Makita, Naoto Jikutani, Kazuhiro Harasaka, Shunichi Sato, Satoru Sugawara
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Patent number: 8111724Abstract: Current may be passed through an n-doped semiconductor region, a recessed metal semiconductor alloy portion, and a p-doped semiconductor region so that the diffusion of majority charge carriers in the doped semiconductor regions transfers heat from or into the semiconductor waveguide through Peltier-Seebeck effect. Further, a temperature control device may be configured to include a metal semiconductor alloy region located in proximity to an optoelectronic device, a first semiconductor region having a p-type doping, and a second semiconductor region having an n-type doping. The temperature of the optoelectronic device may thus be controlled to stabilize the performance of the optoelectronic device.Type: GrantFiled: July 7, 2009Date of Patent: February 7, 2012Assignee: International Business Machines CorporationInventors: Solomon Assefa, William M. Green, Younghee Kim, Joris Van Campenhout, Yurii Vlasov
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Patent number: 8107507Abstract: A primary surface 23a of a supporting base 23 of a light-emitting diode 21a tilts by an off-angle of 10 degrees or more and less than 80 degrees from the c-plane. A semiconductor stack 25a includes an active layer having an emission peak in a wavelength range from 400 nm to 550 nm. The tilt angle “A” between the (0001) plane (the reference plane SR3 shown in FIG. 5) of the GaN supporting base and the (0001) plane of a buffer layer 33a is 0.05 degree or more and 2 degrees or less. The tilt angle “B” between the (0001) plane of the GaN supporting base (the reference plane SR4 shown in FIG. 5) and the (0001) plane of a well layer 37a is 0.05 degree or more and 2 degrees or less. The tilt angles “A” and “B” are formed in respective directions opposite to each other with reference to the c-plane of the GaN supporting base.Type: GrantFiled: December 10, 2010Date of Patent: January 31, 2012Assignee: Sumitomo Electric Industries, Ltd.Inventors: Yusuke Yoshizumi, Yohei Enya, Masaki Ueno, Fumitake Nakanishi
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Patent number: 8102891Abstract: 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.Type: GrantFiled: March 3, 2010Date of Patent: January 24, 2012Assignee: Nichia CorporationInventors: Tomonori Morizumi, Atsuo Michiue, Hiroaki Takahashi
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Patent number: 8098700Abstract: A laser system employing amplification via a single exciton regime and to optical gain media having single exciton amplification is provided.Type: GrantFiled: May 15, 2008Date of Patent: January 17, 2012Assignee: Los Alamos National Security, LLCInventors: Victor I. Klimov, Sergei A. Ivanov
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Patent number: 8077751Abstract: A bar-shaped semiconductor laser chip that can hold down a variation in oscillation wavelength is provided. The bar-shaped semiconductor laser chip has a nitride semiconductor substrate and a semiconductor layer formed on the main surface of the nitride semiconductor substrate and including a plurality of laser chip portions. The plurality of laser chip portions are arrayed in the [11-20] direction. The main surface of the nitride semiconductor substrate is a (0001) plane having an off-angle in the direction along the [11-20] direction. The central part of the main surface of the nitride semiconductor substrate has an off-angle of 0.05±0.1 degrees from the (0001) plane in the direction along the [11-20] direction.Type: GrantFiled: October 5, 2009Date of Patent: December 13, 2011Assignee: Sanyo Electric Co., Ltd.Inventors: Yasuo Baba, Yasuhiko Matsushita, Yukio Gotoh
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Publication number: 20110299560Abstract: In the method for fabricating a III-nitride semiconductor laser device, a substrate product is formed, and the substrate product has a laser structure including a substrate that is made of a hexagonal III-nitride semiconductor and has a semipolar primary surface, and the semiconductor region is formed on the semipolar primary surface, and thereafter a first surface of the substrate product is scribed to form a scribed mark extending in a direction of the a-axis of the hexagonal III-nitride semiconductor. After forming the scribed mark, breakup of the substrate product is carried out by press against a second region of the substrate product while supporting a first region of the substrate product but not supporting the second region. This step results in forming another substrate product and a laser bar. The substrate product is divided into two, the first region and the second region, by a predetermined reference line, and the first and second regions are adjacent to each other.Type: ApplicationFiled: July 15, 2010Publication date: December 8, 2011Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Shimpei TAKAGI, Yusuke YOSHIZUMI, Koji KATAYAMA, Masaki UENO, Takatoshi IKEGAMI
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Publication number: 20110292956Abstract: 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.Type: ApplicationFiled: August 12, 2011Publication date: December 1, 2011Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Shimpei TAKAGI, Yusuke YOSHIZUMI, Koji KATAYAMA, Masaki UENO, Takatoshi IKEGAMI
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Publication number: 20110286484Abstract: A system and method for providing laser diodes emitting multiple wavelengths is described. Multiple wavelengths and/or colors of laser output are obtained by having multiple laser devices, each emitting a different wavelength, packaged onto the same substrate. In other embodiments, multiple laser devices having different wavelengths are formed from the same substrate.Type: ApplicationFiled: May 24, 2011Publication date: November 24, 2011Applicant: Sorra, Inc.Inventors: James W. Raring, Paul Rudy, Eric Hall
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Patent number: 8035676Abstract: 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.Type: GrantFiled: April 30, 2009Date of Patent: October 11, 2011Assignee: Ricoh Company, Ltd.Inventors: Kazuhiro Harasaka, Shunichi Sato, Naoto Jikutani, Toshihiro Ishii
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Publication number: 20110235665Abstract: A compositionally graded semiconductor device and a method of making same are disclosed that provides an efficient p-type doping for wide bandgap semiconductors by exploiting electronic polarization within the crystalline lattice. The compositional graded semiconductor graded device includes a graded heterojunction interface that exhibits a 3D bound polarization-induced sheet charge that spreads in accordance with ??(z)=??·P(z), where ??(z) is a volume charge density in a polar (z) direction, and ? is a divergence operator, wherein the graded heterojunction interface is configured to exhibit substantially equivalent conductivities along both lateral and vertical directions relative to the graded heterojunction interface.Type: ApplicationFiled: December 14, 2010Publication date: September 29, 2011Inventors: John SIMON, Debdeep JENA, Huili XING
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Publication number: 20110228804Abstract: Provided is a group-III nitride semiconductor laser device with a laser cavity of high lasing yield, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured faces 27, 29 to form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser device 11 has a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface 17a. For this reason, it is feasible to make use of emission by a band transition enabling the low threshold current. In a laser structure 13, a first surface 13a is opposite to a second surface 13b. The first and second fractured faces 27, 29 extend from an edge 13c of the first surface 13a to an edge 13d of the second surface 13b. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.Type: ApplicationFiled: July 14, 2010Publication date: September 22, 2011Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Yusuke YOSHIZUMI, Shimpei TAKAGI, Yohei ENYA, Takashi KYONO, Masahiro ADACHI, Masaki UENO, Takamichi SUMITOMO, Shinji TOKUYAMA, Koji KATAYAMA, Takao NAKAMURA, Takatoshi IKEGAMI
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Publication number: 20110217077Abstract: A surface-emitting laser device configured to emit laser light in a direction perpendicular to a substrate includes a p-side electrode surrounding an emitting area on an emitting surface to emit the laser light; and a transparent dielectric film formed on an outside area outside a center part of the emitting area and within the emitting area to lower a reflectance to be less than that of the center part. The outside area within the emitting area has shape anisotropy in two mutually perpendicular directions.Type: ApplicationFiled: November 24, 2009Publication date: September 8, 2011Applicant: Ricoh Company, Ltd.Inventors: Kazuhiro Harasaka, Shunichi Sato, Naoto Jikutani
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Publication number: 20110216795Abstract: An optoelectronic device grown on a miscut of GaN, wherein the miscut comprises a semi-polar GaN crystal plane (of the GaN) miscut x degrees from an m-plane of the GaN and in a c-direction of the GaN, where ?15<x<?1 and 1<x<15 degrees.Type: ApplicationFiled: March 4, 2011Publication date: September 8, 2011Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Po Shan Hsu, Kathryn M. Kelchner, Robert M. Farrell, Daniel A. Haeger, Hiroaki Ohta, Anurag Tyagi, Shuji Nakamura, Steven P. DenBaars, S. James Speck
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Publication number: 20110211607Abstract: An object of the present invention is to provide a nitride semiconductor device which shifts a luminescence wavelength toward a longer wavelength side without decreasing luminescence efficiency, and the nitride semiconductor device according to an implementation of the present invention includes: a GaN layer having a (0001) plane and a plane other than the (0001) plane; and an InGaN layer which contacts the GaN layer and includes indium, and the InGaN layer has a higher indium composition ratio in a portion that contacts the plane other than the (0001) plane than in a portion that contacts the (0001) plane.Type: ApplicationFiled: May 11, 2011Publication date: September 1, 2011Applicant: Panasonic CorporationInventors: Toshiyuki Takizawa, Tetsuzo Ueda
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Publication number: 20110211604Abstract: The present invention relates to a surface-emitting semiconductor laser having a vertical resonator, comprising a substrate base section (1) and a mesa (M) arranged on and/or at the substrate base section, the mesa substantially comprising, viewed perpendicular to the substrate base section: at least one part of a first doting region (2) facing the substrate base section, at least one part of a second doping region (4) facing away from the substrate base section, and an active region (3) arranged between the first and the second doping regions, said active region having at least one active layer (A) with a laser-emitting zone, emitting substantially perpendicular to the active layer, characterized in that the mesa (M) comprises in at least one partial section of the side flank thereof at least one constriction (E).Type: ApplicationFiled: May 5, 2009Publication date: September 1, 2011Applicant: UNIVERSITÄT ULMInventor: Ralf-Hendrik Roscher
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Publication number: 20110188528Abstract: Injection efficiency in both polar and non-polar III-nitride light-emitting structures is strongly deteriorated by inhomogeneous population of different quantum wells (QWs) in multiple QW (MQW) active region of the emitter. Inhomogeneous QW population becomes stronger in long-wavelength emitters with deeper active QWs. In both polar and non-polar structures, indium and/or aluminum incorporation into optical waveguide layers and/or barrier layers of the active region, depending on the desired wavelength of the light to be emitted, improves the uniformity of QW population and increases the structure injection efficiency.Type: ApplicationFiled: January 26, 2011Publication date: August 4, 2011Applicant: OSTENDO TECHNOLOGIES, INC.Inventors: Mikhail V. Kisin, Hussein S. El-Ghoroury
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Publication number: 20110182310Abstract: A nitride semiconductor laser diode includes a substrate of n-type GaN, and a multilayer structure including an n-type cladding layer of AlxGa1-xN (where 0<x<1) formed on and in contact with a main surface of the substrate, an MQW active layer formed on the n-type cladding layer, and a p-type cladding layer formed on the MQW active layer. The main surface of the substrate is oriented at an angle ranging from 0.25° to 0.7° with respect to a (0001) plane of a plane orientation. The composition x of the AlxGa1-xN is in a range from 0.025 to 0.04.Type: ApplicationFiled: April 5, 2011Publication date: July 28, 2011Applicant: PANASONIC CORPORATIONInventors: Tomohito Yabushita, Yasutoshi Kawaguchi, Akio Ueta, Akihiko Ishibashi
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Publication number: 20110182311Abstract: Provided is a gallium nitride based semiconductor light-emitting device with a structure capable of enhancing the degree of polarization. A light-emitting diode 11a is provided with a semiconductor region 13, an InGaN layer 15 and an active layer 17. The semiconductor region 13 has a primary surface 13a having semipolar nature, and is made of GaN or AlGaN. The primary surface 13a of the semiconductor region 13 is inclined at an angle ? with respect to a plane Sc perpendicular to a reference axis Cx which extends in a direction of the [0001] axis in the primary surface 13a. The thickness D13 of the semiconductor region 13 is larger than the thickness DInGaN of the InGaN layer 17, and the thickness DInGaN of the InGaN layer 15 is not less than 150 nm. The InGaN layer 15 is provided directly on the primary surface 13a of the semiconductor region 13 and is in contact with the primary surface 13a.Type: ApplicationFiled: April 7, 2011Publication date: July 28, 2011Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Yusuke YOSHIZUMI, Yohei ENYA, Masaki UENO, Takashi KYONO
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Publication number: 20110164637Abstract: Provided is a group-III nitride semiconductor laser device with a laser cavity allowing for a low threshold current, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured faces 27, 29 to form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser device 11 has a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface 17a. For this reason, it is feasible to make use of emission by a band transition enabling the low threshold current. In a laser structure 13, a first surface 13a is opposite to a second surface 13b. The first and second fractured faces 27, 29 extend from an edge 13c of the first surface 13a to an edge 13d of the second surface 13b. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.Type: ApplicationFiled: March 17, 2011Publication date: July 7, 2011Applicant: Sumitomo Electric Industries, Ltd.Inventors: Yusuke YOSHIZUMI, Yohei ENYA, Takashi KYONO, Masahiro ADACHI, Katsushi AKITA, Masaki UENO, Takamichi SUMITOMO, Shinji TOKUYAMA, Koji KATAYAMA, Takao NAKAMURA, Takatoshi IKEGAMI
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Patent number: 7974322Abstract: A nitride semiconductor laser device includes: a substrate made of silicon in which a plane orientation of a principal surface is a {100} plane; and a semiconductor laminate that includes a plurality of semiconductor layers formed on the substrate and includes a multiple quantum well active layer, each of the plurality of semiconductor layers being made of group III-V nitride. The semiconductor laminate has a plane parallel to a {011} plane which is a plane orientation of silicon as a cleavage face and the cleavage face constructs a facet mirror.Type: GrantFiled: January 13, 2010Date of Patent: July 5, 2011Assignee: Panasonic CorporationInventors: Tetsuzo Ueda, Daisuke Ueda
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Publication number: 20110158276Abstract: In a III-nitride semiconductor laser device, a laser structure includes a support base comprised of a hexagonal III-nitride semiconductor and having a semipolar primary surface, and a semiconductor region provided on the semipolar primary surface of the support base. An electrode is provided on the semiconductor region of the laser structure. The c-axis of the hexagonal III-nitride semiconductor of the support base is inclined at an angle ALPHA with respect to a normal axis toward the m-axis of the hexagonal III-nitride semiconductor. The angle ALPHA is in the range of not less than 45 degrees and not more than 80 degrees or in the range of not less than 100 degrees and not more than 135 degrees. The laser structure includes first and second fractured faces that intersect with an m-n plane defined by the m-axis of the hexagonal III-nitride semiconductor and the normal axis. A laser cavity of the III-nitride semiconductor laser device includes the first and second fractured faces.Type: ApplicationFiled: July 15, 2010Publication date: June 30, 2011Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Shimpei TAKAGI, Yusuke YOSHIZUMI, Koji KATAYAMA, Masaki UENO, Takatoshi IKEGAMI
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Publication number: 20110158275Abstract: In a III-nitride semiconductor laser device, a laser structure includes a support base comprised of a hexagonal III-nitride semiconductor and having a semipolar primary surface, and a semiconductor region provided on the semipolar primary surface of the support base. An electrode is provided on the semiconductor region of the laser structure.Type: ApplicationFiled: July 15, 2010Publication date: June 30, 2011Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Yusuke YOSHIZUMI, Shimpei TAKAGI, Takatoshi IKEGAMI, Masaki UENO, Koji KATAYAMA
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Publication number: 20110158277Abstract: A III-nitride semiconductor laser device is provided with a laser structure and an electrode. The laser structure includes a support base which comprises a hexagonal III-nitride semiconductor and has a semipolar primary surface, and a semiconductor region provided on the semipolar primary surface. The electrode is provided on the semiconductor region. The semiconductor region includes a first cladding layer of a first conductivity type GaN-based semiconductor, a second cladding layer of a second conductivity type GaN-based semiconductor, and an active layer provided between the first cladding layer and the second cladding layer. The laser structure includes first and second fractured faces intersecting with an m-n plane defined by the m-axis of the hexagonal III-nitride semiconductor and an axis normal to the semipolar primary surface. A laser cavity of the III-nitride semiconductor laser device includes the first and second fractured faces.Type: ApplicationFiled: July 16, 2010Publication date: June 30, 2011Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Yusuke YOSHIZUMI, Yohei ENYA, Takashi KYONO, Takamichi SUMITOMO, Nobuhiro SAGA, Masahiro ADACHI, Kazuhide SUMIYOSHI, Shinji TOKUYAMA, Shimpei TAKAGI, Takatoshi IKEGAMI, Masaki UENO, Koji KATAYAMA
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Patent number: 7965752Abstract: A semiconductor laser device operable to emit light having a desired wavelength in the green spectral range. The semiconductor laser device may include a pumping source and a laser structure including a substrate, a first cladding layer, and one or more active region layers. The one or more active region layers include a number of quantum wells having a spontaneous emission peak wavelength that is greater than about 520 nm at a reference pumping power density. The pumping source is configured to pump each quantum well at a pumping power density such that a stimulated emission peak of each quantum well is within the green spectral range, and the number of quantum wells within the one or more active region layers is such that a net optical gain of the quantum wells is greater than a net optical loss coefficient at the desired wavelength in the green spectral range.Type: GrantFiled: November 30, 2009Date of Patent: June 21, 2011Assignee: Corning IncorporatedInventors: Rajaram Bhat, Chad Stephen Gallinat, Jerome Napierala, Dmitry Sizov, Chung-En Zah
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Patent number: 7961768Abstract: An integrated semiconductor laser device capable of improving the properties of a laser beam and reducing the cost for optical axis adjustment is provided. This integrated semiconductor laser device comprises a first semiconductor laser element including a first emission region and having either a projecting portion or a recess portion and a second semiconductor laser element including a second emission region and having either a recess portion or a projecting portion. Either the projecting portion or the recess portion of the first semiconductor laser element is fitted to either the recess portion or the projecting portion of the second semiconductor laser element.Type: GrantFiled: October 23, 2008Date of Patent: June 14, 2011Assignee: Sanyo Electric Co., Ltd.Inventors: Hiroaki Izu, Tsutomu Yamaguchi, Hiroki Ohbo, Ryoji Hiroyama, Masayuki Hata, Kiyoshi Oota
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Publication number: 20110116147Abstract: A disclosed surface emitting laser device includes an oscillator structure including an active layer, semiconductor multilayer reflection mirrors sandwiching the oscillator structure, an electrode provided on an emitting surface where light is emitted in a manner such that the electrode surrounds an emitting region, and a dielectric film formed in at least one region outside a center part of the emitting region so that a refractive index of the region outside the center part of the emitting region is less than the refractive index of the center part of the emitting region. When viewed from an emitting direction of the light, a part of the electrode overlaps a part of the dielectric film.Type: ApplicationFiled: November 1, 2010Publication date: May 19, 2011Applicant: RICOH COMPANY, LTD.Inventors: Hiroshi MOTOMURA, Shunichi Sato
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Patent number: 7933303Abstract: Provided is a group-III nitride semiconductor laser device with a laser cavity allowing for a low threshold current, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured faces 27, 29 to form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser device 11 has a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface 17a. For this reason, it is feasible to make use of emission by a band transition enabling the low threshold current. In a laser structure 13, a first surface 13a is opposite to a second surface 13b. The first and second fractured faces 27, 29 extend from an edge 13c of the first surface 13a to an edge 13d of the second surface 13b. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.Type: GrantFiled: July 27, 2010Date of Patent: April 26, 2011Assignee: Sumitomo Electric Industries, Ltd.Inventors: Yusuke Yoshizumi, Yohei Enya, Takashi Kyono, Masahiro Adachi, Katsushi Akita, Masaki Ueno, Takamichi Sumitomo, Shinji Tokuyama, Koji Katayama, Takao Nakamura, Takatoshi Ikegami
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Publication number: 20110064101Abstract: A low voltage laser device having an active region configured for one or more selected wavelengths of light emissions.Type: ApplicationFiled: September 16, 2010Publication date: March 17, 2011Applicant: Kaai, Inc.Inventors: James W. Raring, Mathew Schmidt, Christiane Poblenz
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Publication number: 20110064100Abstract: An optical device having a structured active region configured for one or more selected wavelengths of light emissions and formed on an off-cut m-plane gallium and nitrogen containing substrate.Type: ApplicationFiled: September 15, 2010Publication date: March 17, 2011Applicant: Kaai, Inc.Inventors: James W. Raring, Nick Pfister, Mathew Schmidt, Christiane Poblenz
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Publication number: 20110064102Abstract: An optical device having a structured active region configured for one or more selected wavelengths of light emissions and formed on an off-cut m-plane gallium and nitrogen containing substrate.Type: ApplicationFiled: September 17, 2010Publication date: March 17, 2011Applicant: Kaai, Inc.Inventors: James W. Raring, Nick Pfister, Mathew Schmidt, Christiane Poblenz
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Publication number: 20110032965Abstract: Optical gain of a nonpolar or semipolar Group-III nitride diode laser is controlled by orienting an axis of light propagation in relation to an optical polarization direction or crystallographic orientation of the diode laser. The axis of light propagation is substantially perpendicular to the mirror facets of the diode laser, and the optical polarization direction is determined by the crystallographic orientation of the diode laser. To maximize optical gain, the axis of light propagation is oriented substantially perpendicular to the optical polarization direction or crystallographic orientation.Type: ApplicationFiled: October 20, 2010Publication date: February 10, 2011Applicants: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA, JAPAN SCIENCE AND TECHNOLOGY AGENCYInventors: Robert M. Farrell, Mathew C. Schmidt, Kwang Choong Kim, Hisashi Masui, Daniel F. Feezell, James S. Speck, Steven P. DenBaars, Shuji Nakamura
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Patent number: 7884447Abstract: A microelectronic assembly in which a semiconductor device structure is directionally positioned on an off-axis substrate (201). In an illustrative implementation, a laser diode is oriented on a GaN substrate (201) wherein the GaN substrate includes a GaN (0001) surface off-cut from the <0001> direction predominantly towards either the <1120> or the <1100> family of directions. For a <1120> off-cut substrate, a laser diode cavity (207) may be oriented along the <1100> direction parallel to lattice surface steps (202) of the substrate (201) in order to have a cleaved laser facet that is orthogonal to the surface lattice steps. For <1100> off-cut substrate, the laser diode cavity may be oriented along the <1100> direction orthogonal to lattice surface steps (207) of the substrate (201) in order to provide a cleave laser facet that is aligned with the surface lattice steps.Type: GrantFiled: June 27, 2006Date of Patent: February 8, 2011Assignee: Cree, Inc.Inventors: George R. Brandes, Robert P. Vaudo, Xueping Xu
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Patent number: 7879632Abstract: Provided is a method for manufacturing a surface-emitting laser capable of forming a photonic crystal structure inside a semiconductor highly accurately and easily without direct bonding. It is a method by laminating on a substrate a plurality of semiconductor layers including an active layer and a semiconductor layer having a photonic crystal structure formed therein, the method including the steps of forming a second semiconductor layer on a first semiconductor layer to form the photonic crystal structure, forming a plurality of microholes in the second semiconductor layer, forming a low refractive index portion in a part of the first semiconductor layer via the plurality of microholes thereby to provide the first semiconductor layer with the photonic crystal structure having a one-dimensional or two-dimensional refractive index distribution in a direction parallel to the substrate, and forming a third semiconductor layer by crystal regrowth from a surface of the second semiconductor layer.Type: GrantFiled: July 2, 2008Date of Patent: February 1, 2011Assignee: Canon Kabushiki KaishaInventor: Mitsuhiro Ikuta
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Patent number: 7878205Abstract: A manufacturing method for quasi phase matching (QPM) wavelength converter elements using crystal quartz as a base material in which twins are periodically induced, comprises a step of periodically inducing the twins by applying a stress onto a crystal quartz substrate as the base material so that an angle ? of a direction in which the stress is applied relative to a Z axis of the crystal quartz is 60°<?<90°.Type: GrantFiled: October 5, 2007Date of Patent: February 1, 2011Assignees: National Institute for Materials Science, Nidek Co., Ltd.Inventors: Sunao Kurimura, Tsuyoshi Yamada
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Patent number: 7873088Abstract: A primary surface 23a of a supporting base 23 of a light-emitting diode 21a tilts by an off-angle of 10 degrees or more and less than 80 degrees from the c-plane. A semiconductor stack 25a includes an active layer having an emission peak in a wavelength range from 400 nm to 550 nm. The tilt angle “A” between the (0001) plane (the reference plane SR3 shown in FIG. 5) of the GaN supporting base and the (0001) plane of a buffer layer 33a is 0.05 degree or more and 2 degrees or less. The tilt angle “B” between the (0001) plane of the GaN supporting base (the reference plane SR4 shown in FIG. 5) and the (0001) plane of a well layer 37a is 0.05 degree or more and 2 degrees or less. The tilt angles “A” and “B” are formed in respective directions opposite to each other with reference to the c-plane of the GaN supporting base.Type: GrantFiled: May 13, 2010Date of Patent: January 18, 2011Assignee: Sumitomo Electric Industries, Ltd.Inventors: Yusuke Yoshizumi, Yohei Enya, Masaki Ueno, Fumitake Nakanishi
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Publication number: 20100322276Abstract: Provided is a group-III nitride semiconductor laser device with a laser cavity allowing for a low threshold current, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured faces 27, 29 to form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser device 11 has a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface 17a. For this reason, it is feasible to make use of emission by a band transition enabling the low threshold current. In a laser structure 13, a first surface 13a is opposite to a second surface 13b. The first and second fractured faces 27, 29 extend from an edge 13c of the first surface 13a to an edge 13d of the second surface 13b. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.Type: ApplicationFiled: July 27, 2010Publication date: December 23, 2010Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Yusuke YOSHIZUMI, Yohei ENYA, Takashi KYONO, Masahiro ADACHI, Katsushi AKITA, Masaki UENO, Takamichi SUMITOMO, Shinji TOKUYAMA, Koji KATAYAMA, Takao NAKAMURA, Takatoshi IKEGAMI
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Publication number: 20100316075Abstract: An optical device includes a gallium nitride substrate member having an m-plane nonpolar crystalline surface region characterized by an orientation of about ?2 degrees to about 2 degrees towards (000-1) and less than about 0.5 degrees towards (11-20). The device also has a laser stripe region formed overlying a portion of the m-plane nonpolar crystalline orientation surface region. A first cleaved c-face facet is provided on one end of the laser stripe region, and a second cleaved c-face facet is provided on the other end of the laser stripe region.Type: ApplicationFiled: April 13, 2010Publication date: December 16, 2010Applicant: Kaai, Inc.Inventors: James W. Raring, Daniel F. Feezell, Nicholas J. Pfister, Rajat Sharma
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Patent number: 7852892Abstract: A ridge stripe semiconductor laser device includes a first conductivity type cladding layer 103, an active layer 104, a second conductivity type first cladding layer 105, a second conductivity type second cladding layer 108 in a ridge-shaped stripe for confining light in a horizontal transverse direction, and a current blocking layer 107 formed in a region except for at least a part on a ridge that are disposed on a semiconductor substrate 102. In a cross-section perpendicular to a stripe direction of the ridge, each of both lateral surfaces of the ridge includes a first surface 118 that is substantially perpendicular to a surface of the semiconductor substrate and extends downward from an upper end of the ridge, and a second surface 119 that is formed of a substantially linear skirt portion inclined surface that is inclined obliquely downward to an outside of the ridge in a skirt portion of the ridge.Type: GrantFiled: January 12, 2006Date of Patent: December 14, 2010Assignee: Panasonic CorporationInventors: Hiroyuki Hosoi, Kouji Makita, Michinari Yamanaka
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Patent number: 7843980Abstract: An inventive semiconductor laser diode includes a Group III nitride semiconductor layered structure having a major crystal growth plane defined by a non-polar or semi-polar-plane. The Group III nitride semiconductor layered structure includes: a p-type cladding layer and an n-type cladding layer; an In-containing p-type guide layer and an In-containing n-type guide layer held between the p-type cladding layer and the n-type cladding layer; and an In-containing light emitting layer held between the p-type guide layer and the n-type guide layer.Type: GrantFiled: May 15, 2008Date of Patent: November 30, 2010Assignee: Rohm Co., Ltd.Inventors: Hiroaki Ohta, Kuniyoshi Okamoto
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Patent number: 7839903Abstract: Optical gain of a nonpolar or semipolar Group-III nitride diode laser is controlled by orienting an axis of light propagation in relation to an optical polarization direction or crystallographic orientation of the diode laser. The axis of light propagation is substantially perpendicular to the mirror facets of the diode laser, and the optical polarization direction is determined by the crystallographic orientation of the diode laser. To maximize optical gain, the axis of light propagation is oriented substantially perpendicular to the optical polarization direction or crystallographic orientation.Type: GrantFiled: February 12, 2008Date of Patent: November 23, 2010Assignees: The Regents of the University of California, Japan Science and Technology AgencyInventors: Robert M. Farrell, Mathew C. Schmidt, Kwang-Choong Kim, Hisashi Masui, Daniel F. Feezell, James S. Speck, Steven P. DenBaars, Shuji Nakamura
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Publication number: 20100290492Abstract: A method of producing a nitride semiconductor laser device includes forming a wafer including a nitride semiconductor layer of a first conductivity type, an active layer of a nitride semiconductor, a nitride semiconductor layer of a second conductivity type, and an electrode pad for the second conductivity type stacked in this order on a main surface of a conductive substrate and also including stripe-like waveguide structures parallel to the active layer; cutting the wafer to obtain a first type and a second type of laser device chips; and distinguishing between the first type and the second type of chips by automatic image recognition. The first type and the second type of chips are different from each other in position of the stripe-like waveguide structure with respect to a width direction of each chip and also in area ratio of the electrode pad to the main surface of the substrate.Type: ApplicationFiled: June 28, 2010Publication date: November 18, 2010Inventor: Yukio Yamasaki
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Publication number: 20100284432Abstract: A surface emitting laser array having a plurality of surface emitting lasers arranged in an array, each of the surface emitting lasers being provided with a two-dimensional photonic crystal having a resonance mode in an in-plane direction and with an active layer. The surface emitting laser has a mesa-shaped inclined side wall surface. When a maximum light-receiving angle with respect to the mesa-shaped inclined side wall surface at which an incident light is coupled with a waveguide containing the two-dimensional photonic crystal is denoted as ?max°, an angle formed by a plane of the two-dimensional photonic crystal and the mesa-shaped inclined side wall surface is controlled so as to exceed (90+?max)° or be smaller than (90??max)°.Type: ApplicationFiled: May 4, 2010Publication date: November 11, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Katsuyuki Hoshino, Shoichi Kawashima
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Patent number: 7813397Abstract: A nitride semiconductor laser device includes, on a first principle face of the (0001) of a nitride semiconductor substrate, a nitride semiconductor layer having a first conductivity type, an active layer, and a nitride semiconductor layer having a second conductivity type that is different from the first conductivity type, and being formed a stripe ridge on the surface thereof. The (000-1) face and an inclined face other than the (000-1) face are exposed on a second principal face of the nitride semiconductor substrate. The inclined face other than the (000-1) face represents no less than 0.5% over the surface area of the second principal face.Type: GrantFiled: April 9, 2008Date of Patent: October 12, 2010Assignee: Nichia CorporationInventors: Yuji Matsuyama, Shinji Suzuki, Kousuke Ise, Atsuo Michiue, Akinori Yoneda
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Patent number: 7792172Abstract: A nitride semiconductor laser device has a multilayer structure formed by stacking a plurality of nitride semiconductor layers made of hexagonal nitride semiconductors, while the multilayer structure is provided with a waveguide structure for guiding a laser beam, the nitride semiconductor layers forming the multilayer structure are stacked in a direction substantially perpendicular to the c-axes of the hexagonal nitride semiconductors constituting the nitride semiconductor layers, a first cavity facet forming a side surface of the waveguide structure is a c-plane having Ga-polarity, a second cavity facet forming another side surface of the waveguide structure opposed to the first cavity facet is a c-plane having N-polarity, a crystalline nitrogen-containing film is formed on the surface of the first cavity facet, and the reflectance of the first cavity facet is smaller than the reflectance of the second cavity facet.Type: GrantFiled: October 2, 2008Date of Patent: September 7, 2010Assignee: Sharp Kabushiki KaishaInventors: Yoshinobu Kawaguchi, Takeshi Kamikawa, Shigetoshi Ito