Laser Patents (Class 977/951)
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Patent number: 9036673Abstract: A semiconductor laser includes a semiconductor nanowire of a first conductivity type provided over a substrate, a light emitting layer provided around the semiconductor nanowire and insulated at an upper end and a lower end thereof, a cladding layer of a second conductivity type different from the first conductivity type, the cladding layer being provided at an outer periphery of the light emitting layer, a first electrode electrically coupled to an end portion of the semiconductor nanowire, a second electrode electrically coupled to an outer periphery of the cladding layer, a first reflection mirror provided at a one-end portion side of the semiconductor nanowire, and a second reflection mirror provided at the other end portion side of the semiconductor nanowire.Type: GrantFiled: June 19, 2014Date of Patent: May 19, 2015Assignee: Fujitsu LimitedInventors: Kenichi Kawaguchi, Yoshiaki Nakata
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Publication number: 20150110137Abstract: In one aspect, semiconductor lasers are provided. A semiconductor laser described herein comprises substrate and a cavity formed on the substrate, the cavity comprising an asymmetric Mach-Zehnder (AMZ) interferometer structure positioned between two straight waveguide segments, the straight waveguide segments and first and second arms of the AMZ interferometer structure comprising epitaxial semiconductor layers, wherein the second arm of the AMZ interferometer structure has a temperature control architecture independent of the first arm.Type: ApplicationFiled: October 17, 2013Publication date: April 23, 2015Applicant: Princeton UniversityInventors: Mei Chai Zheng, Qiang Liu, Claire F. Gmachl
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Publication number: 20150098483Abstract: A solid state laser includes an optical resonator cavity and a containment vessel disposed in the optical resonator cavity. The solid state laser also includes a gas-flow system operable to pump solid state nano-structures through the containment vessel and one or more diode pumps optically coupled to the containment vessel.Type: ApplicationFiled: October 3, 2013Publication date: April 9, 2015Applicant: Lawrence Livermore National Security, LLCInventors: Raymond J. Beach, Mark D. Rotter
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Publication number: 20150092806Abstract: Described herein are multi-segmented nanowires, nanosheets and nanobelts, and devices and methods using them for the generation of multicolor and white light.Type: ApplicationFiled: March 14, 2013Publication date: April 2, 2015Inventors: Cun-Zheng Ning, Zhicheng Liu, Leijun Yin, Fan Fan, Hao Ning, Sunay Turdogan, Patricia L. Nichols
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Publication number: 20150063395Abstract: An optoelectronic semiconductor chip, based on a nitride material system, comprising at least one active quantum well, wherein during operation electromagnetic radiation is generated in the active quantum well, the active quantum well comprises N successive zones in a direction parallel to a growth direction z of the semiconductor chip, N being a natural number greater than or equal to 2, the zones are numbered consecutively in a direction parallel to the growth direction z, at least two of the zones have average aluminium contents k which differ from one another, and the active quantum well fulfils the condition: 50??(35?k(z))dz?2.5N?1.5?dz?120.Type: ApplicationFiled: November 6, 2014Publication date: March 5, 2015Inventors: Adrian AVRAMESCU, Désirée Queren, Christoph Eichler, Matthias Sabathil, Stephan Lutgen, Uwe Strauss
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Publication number: 20150043318Abstract: A reader (12) is provided with: a near-field light device (122) having (i) one or a plurality of quantum dots and (ii) an output end (224) laminated on an upper layer of the one or plurality of quantum dot layers; and a light receiving device (124) which is configured to receive light caused by near-field light formed by the near-field light device upon reproduction of record information on a recording medium. According to the reader, the information recorded by heat assisted magnetic recording can be reproduced without providing a separate magnetic circuit.Type: ApplicationFiled: August 27, 2012Publication date: February 12, 2015Inventors: Takayuki Kasuya, Satoshi Sugiura, Katsumi Yoshizawa
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Publication number: 20140301420Abstract: A semiconductor laser includes a semiconductor nanowire of a first conductivity type provided over a substrate, a light emitting layer provided around the semiconductor nanowire and insulated at an upper end and a lower end thereof, a cladding layer of a second conductivity type different from the first conductivity type, the cladding layer being provided at an outer periphery of the light emitting layer, a first electrode electrically coupled to an end portion of the semiconductor nanowire, a second electrode electrically coupled to an outer periphery of the cladding layer, a first reflection mirror provided at a one-end portion side of the semiconductor nanowire, and a second reflection mirror provided at the other end portion side of the semiconductor nanowire.Type: ApplicationFiled: June 19, 2014Publication date: October 9, 2014Inventors: Kenichi Kawaguchi, Yoshiaki NAKATA
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Publication number: 20140269806Abstract: A plasmonic laser device has resonant nanocavities filled with a gain medium containing an organic dye. The resonant plasmon frequencies of the nanocavities are tuned to align with both the absorption and emission spectra of the dye.Type: ApplicationFiled: February 21, 2014Publication date: September 18, 2014Inventors: Mihail BORA, Tiziana C. BOND
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Patent number: 8829652Abstract: A light emitting device with graded composition hole tunneling layer is provided. The device comprises a substrate and an n-type semiconductor layer is disposed on the substrate, in which the n-type semiconductor layer comprises a first portion and a second portion. A graded composition hole tunneling layer is disposed on the first portion of the n-type semiconductor layer. An electron blocking layer is disposed on the graded composition hole tunneling layer. A p-type semiconductor layer is disposed on the electron blocking layer. A first electrode is disposed on the p-type semiconductor layer, and a second electrode is disposed on the second portion of the n-type semiconductor layer and is electrical insulated from the first portion of the n-type semiconductor. The graded composition hole tunneling layer is used as the quantum-well to improve the transport efficiency of the holes to increase the light emitting efficiency of the light emitting device.Type: GrantFiled: July 17, 2012Date of Patent: September 9, 2014Assignee: National Chiao Tung UniversityInventors: Chao-Hsun Wang, Hao-Chung Kuo
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Publication number: 20140116502Abstract: A quantum nanodot 3 is formed of a semiconductor and has an outer diameter in two-dimensional directions which is not more than twice a bore radius of an exciton in the semiconductor. A two-dimensional quantum nanodot array 1 has a structure that the quantum nanodots 3 are two-dimensionally and uniformly arranged with a spacing between the quantum nanodots 3 being 1 nm or more. The two-dimensional nanodot array 1 may include an intermediate layer 6 which is made of a semiconductor or an insulator and is filled between the quantum nanodot arrays 10. Since the quantum nanodots have high orientation and high density, a high quantum confinement effect is attained. Therefore, the quantum nanodot 3 made of Si produces direct transition type luminescence. It is possible to control an optical property and a transport property of the two-dimensional quantum nanodot array 10.Type: ApplicationFiled: June 13, 2012Publication date: May 1, 2014Applicant: TOHOKU UNIVERSITYInventor: Seiji Samukawa
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Patent number: 8674328Abstract: A method of fabricating a nanodevice includes providing a nanowire having a first portion and a second portion. The nanowire has a polymer coating. A nanostructure is provided that is proximate to the second portion of the nanowire. Solely the first portion of the nanowire is irradiated with near-infrared radiation, thereby exciting the first portion to generate ultraviolet radiation. The generated ultraviolet radiation is guided from the first portion along the nanowire toward the second portion, so that a region of the polymer coating on the second portion is polymerized and bonds the nanostructure to the nanowire.Type: GrantFiled: November 14, 2011Date of Patent: March 18, 2014Assignee: University of Maryland College ParkInventors: John T. Fourkas, Linjie Li, Sanghee Nah
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Publication number: 20140064312Abstract: Exemplary embodiments provide semiconductor nanowires and nanowire devices/applications and methods for their formation. In embodiments, in-plane nanowires can be epitaxially grown on a patterned substrate, which are more favorable than vertical ones for device processing and three-dimensional (3D) integrated circuits. In embodiments, the in-plane nanowire can be formed by selective epitaxy utilizing lateral overgrowth and faceting of an epilayer initially grown in a one-dimensional (1D) nanoscale opening. In embodiments, optical, electrical, and thermal connections can be established and controlled between the nanowire, the substrate, and additional electrical or optical components for better device and system performance.Type: ApplicationFiled: September 20, 2013Publication date: March 6, 2014Applicant: STC.UNMInventors: Seung Chang Lee, Steven R.J. Brueck
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Patent number: 8559479Abstract: The invention relates to a method for the production of a photon pair source, which generates entangled photon pairs, having at least one quantum dot, wherein in the method the operational behaviour of the photon pair source is determined by adjusting the fine structure splitting of the excitonic energy level of the at least one quantum dot. It is provided according to the invention for the fine structure splitting of the excitonic energy level to be adjusted by depositing the at least one quantum dot on a {111} crystal surface of a semiconductor substrate.Type: GrantFiled: July 20, 2009Date of Patent: October 15, 2013Assignee: Technische Universitat BerlinInventors: Momme Winkelnkemper, Andrei Schliwa, Dieter Bimberg
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Patent number: 8503071Abstract: Disclosed is a stimulated Raman scattering effect (SRS), amplifying optical fiber that includes a central core comprising a dielectric matrix that is capable of vibrating at a given frequency (?Raman) under the effect of a pump signal. The optical fiber includes at least one kind of metallic nanostructure that is capable of generating surface plasmon resonance (SPR) in the optical fiber. The metallic nanostructures have a shape and composition such that the frequency of their surface plasmon resonance (?plasmon) corresponds to the frequency of the pump signal (?pump) and/or the frequency of the optical signal transmitted in the optical fiber (?signal).Type: GrantFiled: February 19, 2010Date of Patent: August 6, 2013Assignee: Draka Comteq B.V.Inventors: Ekaterina Burov, Alain Pastouret, Cedric Gonnet, Christine Collet, Olivier Cavani
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Patent number: 8467123Abstract: Disclosed is an optical fiber that includes a central core that is suitable for transmitting and amplifying an optical signal and an inner optical cladding that is suitable for confining the optical signal transmitted within the central core. The central core is formed from a core matrix that contains silica-based nanoparticles doped with at least one rare earth element. The disclosed optical fiber can be used with limited optical losses even in an environment with strong ionizing radiation.Type: GrantFiled: December 8, 2009Date of Patent: June 18, 2013Assignee: Draka Comteq B.V.Inventors: Elise Regnier, Alain Pastouret, Ekaterina Burov
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Patent number: 8444264Abstract: An upconverting device for enhanced recognition of selected wavelengths is provided. The device comprises a transparent light transmitter in combination with a plurality of upconverting nanoparticles. The device may a lens in eyewear or alternatively a transparent panel such as a window in an instrument or machine. In use the upconverting device is positioned between a light source and the eye(s) of the user of the upconverting device.Type: GrantFiled: April 27, 2011Date of Patent: May 21, 2013Assignee: Jefferson Science Associates, LLCInventors: Brian Kross, John (Jack) E. McKisson, John McKisson, Andrew Weisenberger, Wenze Xi, Carl Zorn
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Patent number: 8369006Abstract: The present invention provides a photorefractive hybrid cell including a window and a gain media disposed adjacent the window. The gain media includes nanoparticles therein. The window includes a material that forms a space-charge field. The gain media includes a material having refractive index properties that depend on an electric field. The nanoparticles include a material which responds orientationally to the presence of an electric or magnetic field.Type: GrantFiled: April 19, 2011Date of Patent: February 5, 2013Assignee: The United States of America as represented by the Secretary of the Air ForceInventors: Gary Cook, Dean R Evans, Anatoly Gluschenko, Victor Yu Reshetnyak
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Publication number: 20120314726Abstract: Provided are a laser diode using zinc oxide nanorods and a manufacturing method thereof. The laser diode using zinc oxide nanorods according to one embodiment of the present disclosure includes: a wafer; an electrode layer formed on the wafer; a nanorod layer including a plurality of n-doped zinc oxide nanorods grown on the electrode layer; and a p-doped single crystal semiconductor layer that is physically in contact with the ends of the zinc oxide nanorods.Type: ApplicationFiled: September 10, 2010Publication date: December 13, 2012Applicant: DONGGUK UNIVERSITY INDUSTRY-ACADEMIC COOPERATION FOUNDATIONInventors: Sang Wuk Lee, Tae Won Kang, Gennady Panin, Hak Dong Cho
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Publication number: 20120307856Abstract: A semiconductor laser device includes a p-type clad layer and an n-type clad layer, a p-side guide layer and an n-side guide layer interposed between the p-type clad layer and the n-type clad layer, and an active layer interposed between the p-side guide layer and the n-side guide layer. The active layer includes at least two quantum well layers and a barrier layer interposed between the quantum well layers adjoining to each other. Each of the p-type clad layer and the n-type clad layer is formed of a (Alx1Ga(1-x1))0.51In0.49P layer (0?x1?1). Each of the p-side guide layer, the n-side guide layer and the barrier layer is formed of a Alx2Ga(1-x2)As layer (0?x2?1). Each of the quantum well layers is formed of a GaAs(1-x3)Px3 layer (0?x3?1). The (Alx1Ga(1-x1))0.51In0.49P layer has a composition satisfying an inequality, x1>0.7. The Alx2Ga(1-x2)As layer has a composition satisfying an inequality, 0.4?x2?0.8.Type: ApplicationFiled: July 27, 2012Publication date: December 6, 2012Applicant: ROHM CO., LTD.Inventors: Yoshito NISHIOKA, Yoichi Mugino, Tsuguki Noma
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Patent number: 8189636Abstract: Detecting electrical overstress events in electronic circuitry such as optical emitters. In one example embodiment, a laser includes an active area and a contact region in electrical communication with the active area. A portion of the contact region is configured to manifest a change in a visual attribute of the portion in response to exposure of the portion to an electrical overstress event.Type: GrantFiled: September 27, 2010Date of Patent: May 29, 2012Assignee: Finisar CorporationInventor: David Todd Mathes
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Publication number: 20120128018Abstract: A gain medium and an interband cascade laser, having the gain medium are presented. The gain medium can have one or both of the following features: (1) the thicknesses of the one or more hole quantum wells in the hole injector region are reduced commensurate with the thickness of the active hole quantum well in the active quantum well region, so as to place the valence band maximum in the hole injector region at least about 100 meV lower than the valence band maximum in the active hole quantum well; and (2) the thickness of the last well of the electron injector region is between 85 and 110% of the thickness of the first active electron quantum well in the active gain region of the next stage of the medium. A laser incorporating a gain medium in accordance with the present invention can emit in the mid-IR range from about 2.5 to 8 ?m at high temperatures with room-temperature continuous wave operation to wavelengths of at least 4.Type: ApplicationFiled: February 9, 2011Publication date: May 24, 2012Applicant: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Igor Vurgaftman, Jerry R. Meyer, Chadwick L. Canedy, William W. Bewley, James R. Lindle, Chul-soo Kim, Mijin Kim
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Publication number: 20120076166Abstract: An embodiment of the invention relates to a single-photon source for emitting single photons, comprising a cavity having a first mirror and a second mirror and exhibiting a longitudinal resonance frequency between the first and second mirror; at least one quantum dot arranged inside said cavity, said quantum dot being strain-dependent and configured to generate radiation at a strain-dependent radiation frequency; a device capable of exciting the quantum dot to generate radiation; a piezoelectric crystal being arranged outside the cavity and mechanically coupled to the second mirror's outer surface, said piezoelectric crystal configured to receive a control voltage and capable of applying either a laterally tensile and vertically compressive strain to both the cavity and the quantum dot, or a laterally compressive and vertically tensile strain to both the cavity and the quantum dot, depending on the control voltage's polarity; wherein, in response to said strain, the resonance frequency and the radiation frequType: ApplicationFiled: September 27, 2010Publication date: March 29, 2012Inventors: Andrei SCHLIWA, Erik STOCK, Dieter BIMBERG
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Publication number: 20120039350Abstract: Semiconductor structures and laser devices including the semiconductor structures are provided. The semiconductor structures have a quantum cascade laser (QCL) structure including an electron injector, an active region, and an electron extractor. The active region of the semiconductor structures includes a configuration of quantum wells and barriers that virtually suppresses electron leakage, thereby providing laser devices including such structures with superior electro-optical characteristics.Type: ApplicationFiled: August 12, 2010Publication date: February 16, 2012Applicant: WISCONSIN ALUMNI RESEARCH FOUNDATIONInventors: Dan Botez, Jae Cheol Shin
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Publication number: 20120008660Abstract: Provided is a III-nitride semiconductor laser allowing for provision of a low threshold with use of a semipolar plane. A primary surface 13a of a semiconductor substrate 13 is inclined at an angle of inclination AOFF in the range of not less than 50 degrees and not more than 70 degrees toward the a-axis direction of GaN with respect to a reference plane perpendicular to a reference axis Cx along the c-axis direction of GaN. A first cladding layer 15, an active layer 17, and a second cladding layer 19 are provided on the primary surface 13a of the semiconductor substrate 13. The well layers 23a of the active layer 17 comprise InGaN. A polarization degree P in the LED mode of emission from the active layer of the semiconductor laser that reaches lasing is not less than ?1 and not more than 0.1.Type: ApplicationFiled: August 17, 2011Publication date: January 12, 2012Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Kei FUJII, Masaki UENO, Katsushi AKITA, Takashi KYONO, Yusuke YOSHIZUMI, Takamichi SUMITOMO, Yohei ENYA
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Patent number: 8089997Abstract: The laser device has a gain medium, first and second clads sandwiching the gain medium in the thickness direction, and a cavity structure for resonating the electromagnetic wave generated in the gain medium. The gain medium includes a plurality of active regions for generating an electromagnetic wave and at lease one connecting region sandwiched among the active regions. The first and second clads are each formed of a negative permittivity medium having a permittivity the real part of which is negative relative to the electromagnetic wave. A potential-adjusting portion is arranged between the connecting region and the first clad and between the connecting region and the second clad for adjusting the electric potential of the connecting region.Type: GrantFiled: October 20, 2010Date of Patent: January 3, 2012Assignee: Canon Kabushiki KaishaInventors: Masahiro Asada, Ryota Sekiguchi, Toshihiko Ouchi
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Publication number: 20110310915Abstract: Methods and apparatus for improved single-mode selection in a quantum cascade laser. In one example, a distributed feedback grating incorporates both index-coupling and loss-coupling components. The loss-coupling component facilitates selection of one mode from two possible emission modes by periodically incorporating a thin layer of “lossy” semiconductor material on top of the active region to introduce a sufficiently large loss difference between the two modes. The lossy layer is doped to a level sufficient to induce considerable free-carrier absorption losses for one of the two modes while allowing sufficient gain for the other of the two modes. In alternative implementations, the highly-doped layer may be replaced by other low-dimensional structures such as quantum wells, quantum wires, and quantum dots with significant engineered intraband absorption to selectively increase the free-carrier absorption losses for one of multiple possible modes so as to facilitate single-mode operation.Type: ApplicationFiled: November 5, 2009Publication date: December 22, 2011Applicant: President and Fellows of Harvard CollegeInventors: Federico Capasso, Benjamin G. Lee, Christian Pflugl, Laurent Diehl, Mikhail A. Belkin
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Publication number: 20110313407Abstract: Aspects of the present disclosure relate to the field of laser technology, specifically semiconductor lasers, and to novel biomedical applications of such lasers, including novel methods of photodynamic therapy. Exemplary embodiments of the present disclosure include a semiconductor laser diode having an active region having a gain medium with one or more InGaAs/InAs quantum dot layers; and wherein the laser diode can be arranged in operation to emit laser light having a central wavelength within spectral range of wave lengths. The present embodiments further include a method of directly forming a reactive oxygen species (ROS), the method including exposing a medium having a potential source of ROS to a semiconductor laser diode, the semiconductor laser diode configured to emit laser light having a central wavelength within the spectral range.Type: ApplicationFiled: June 20, 2011Publication date: December 22, 2011Inventors: Edik U. Rafailov, Svetlana Zolotovskaya, Sergei Sokolovski
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Publication number: 20110310920Abstract: Exemplary embodiments provide semiconductor nanowires and nanowire devices/applications and methods for their formation. In embodiments, in-plane nanowires can be epitaxially grown on a patterned substrate, which are more favorable than vertical ones for device processing and three-dimensional (3D) integrated circuits. In embodiments, the in-plane nanowire can be formed by selective epitaxy utilizing lateral overgrowth and faceting of an epilayer initially grown in a one-dimensional (1D) nanoscale opening. In embodiments, optical, electrical, and thermal connections can be established and controlled between the nanowire, the substrate, and additional electrical or optical components for better device and system performance.Type: ApplicationFiled: September 1, 2011Publication date: December 22, 2011Applicant: STC.UNMInventors: Seung Chang Lee, Steven R. J. Brueck
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Publication number: 20110292958Abstract: 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: ApplicationFiled: May 28, 2010Publication date: December 1, 2011Inventor: Rajaram Bhat
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Publication number: 20110292957Abstract: 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: ApplicationFiled: May 28, 2010Publication date: December 1, 2011Inventors: Rajaram Bhat, Dmitry Sizov
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Patent number: 8018648Abstract: The present invention provides a photorefractive hybrid cell including a window and a gain media disposed adjacent the window. The gain media includes nanoparticles therein. The window includes a material that forms a space-charge field. The gain media includes a material having refractive index properties that depend on an electric field. The nanoparticles include a material which responds orientationally to the presence of an electric or a magnetic field.Type: GrantFiled: June 12, 2008Date of Patent: September 13, 2011Assignee: United States of America as represented by the Secretary of the Air ForceInventors: Gary Cook, Dean R. Evans, Anatoly Gluschenko, Victor Yu Reshetnyak
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Publication number: 20110210658Abstract: A ceramic composite laminate includes a wavelength-converting layer and a non-emissive layer, wherein the ceramic composite laminate has a wavelength conversion efficiency (WCE) of at least 0.650. The ceramic composite laminate can also include a wavelength-converting ceramic layer comprising an emissive material and a scattering material, wherein the laminated composite has a total transmittance of between about 40% to about 85%. The wavelength-converting layer may be formed from plasma YAG:Ce powder.Type: ApplicationFiled: January 28, 2011Publication date: September 1, 2011Applicant: NITTO DENKO CORPORATIONInventors: Guang PAN, Hironaka FUJII, Hiroaki MIYAGAWA, Rajesh MUKHERJEE, Bin ZHANG, Toshitaka NAKAMURA, Amane MOCHIZUKI
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Publication number: 20110170568Abstract: A surface emitting semiconductor laser includes a substrate, an n-type lower DBR, an n-type cavity extending region formed on the lower DBR, an active region formed on the cavity extending region, and an upper DBR formed on the active region. A difference in refractive index between a relatively high refractive index layer and a relatively low refractive in the upper DBR is smaller than that in the lower DBR.Type: ApplicationFiled: July 8, 2010Publication date: July 14, 2011Applicant: FUJI XEROX CO., LTD.Inventor: Takashi Kondo
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Publication number: 20110164639Abstract: A two terminal semiconductor device for producing light emission in response to electrical signals, includes: a terminal-less semiconductor base region disposed between a semiconductor emitter region and a semiconductor collector region having a tunnel junction adjacent the base region; the base region having a region therein exhibiting quantum size effects; an emitter terminal and a collector terminal respectively coupled with the emitter region and the collector region; whereby application of the electrical signals with respect to the emitter and collector terminals, causes light emission from the base region. Application of the electrical signals is operative to reverse bias the tunnel junction. Holes generated at the tunnel junction recombine in the base region with electrons flowing into the base region, resulting in the light emission. The region exhibiting quantum size effects is operative to aid recombination.Type: ApplicationFiled: December 31, 2010Publication date: July 7, 2011Inventors: Nick Holonyak, JR., Milton Feng, Gabriel Walter, Adam James
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Publication number: 20110150018Abstract: Provided is a laser device. In the laser device, an active layer is connected to a stem core of a 1×2 splitter on a substrate, a first diffraction grating is coupled to a first twig core of the 1×2 splitter, and a second diffraction grating is coupled to a second twig core of the 1×2 splitter. An active layer-micro heater is designed to supply heat to the active layer. First and second micro heaters are designed to supply heats to the first and second diffraction gratings, respectively, thereby varying a Bragg wavelength.Type: ApplicationFiled: August 13, 2010Publication date: June 23, 2011Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTEInventors: Kyung Hyun PARK, Namje Kim, Young Ahn Leem, Sang-Pil Han, Chul-Wook Lee, Jaeheon Shin, Eundeok Sim, Yongsoon Baek
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Publication number: 20110142088Abstract: The invention relates to a method for the production of a photon pair source, which generates entangled photon pairs, having at least one quantum dot, wherein in the method the operational behaviour of the photon pair source is determined by adjusting the fine structure splitting of the excitonic energy level of the at least one quantum dot. It is provided according to the invention for the fine structure splitting of the excitonic energy level to be adjusted by depositing the at least one quantum dot on a {111} crystal surface of a semiconductor substrate.Type: ApplicationFiled: July 20, 2009Publication date: June 16, 2011Inventors: MOMME Winkelnkemper, Andrei Schliwa, Dieter Bimberg
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Publication number: 20110080931Abstract: A semiconductor laser includes a laser resonator (1) having a planar active region (3), a first (2) and a second (6) wave-guide layer that define the active region (3). The resonator (1) has a shape that is defined by a perimeter, along which the first layer (2) radiation guide has a plurality of cuts (4) forming a lattice. The cuts are made as at least two adjacent slits (4a, 4b) and a zone between the slits in which an uncut portion (5a) of wave-guiding layer is present. In the case of a circular semiconductor laser, the number of cuts (4) is a prime number, or an odd number that is a multiple of a prime number, the prime number being greater than or equal to five. This way, it is avoided that resonance modes evolve outside of the zone with the cuts, or in any case with a component that is different from zero of the wave vector in a radial direction, and a pure whispering gallery operating mode is obtained, with maximum of the emitted radiation that evolves in a vertical direction, i.e.Type: ApplicationFiled: November 5, 2010Publication date: April 7, 2011Applicant: SCUOLA NORMALE SUPERIOREInventors: Alessandro TREDICUCCI, Fabio BELTRAM, Lucas MAHLER
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Publication number: 20110069724Abstract: The present invention embraces an optical fiber that includes a central core to transmit optical signals and an optical cladding surrounding the central core to confine transmitted optical signals. The optical fiber typically includes metallic nanostructures for increasing second-order nonlinearity effects. The optical fiber typically has a refractive index profile that ensures a phase-matching condition.Type: ApplicationFiled: September 22, 2010Publication date: March 24, 2011Applicant: DRAKA COMTEQ, B.V.Inventors: Simon Richard, Ekaterina Burov, Alain Pastouret, Olivier Cavani
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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: 20110064103Abstract: A dislocation-free high quality template with relaxed lattice constant, fabricated by spatially restricting misfit dislocation(s) around heterointerfaces. This can be used as a template layer for high In composition devices. Specifically, the present invention prepares high quality InGaN templates (In composition is around 5-10%), and can grow much higher In-composition InGaN quantum wells (QWs) (or multi quantum wells (MQWs)) on these templates than would otherwise be possible.Type: ApplicationFiled: August 23, 2010Publication date: March 17, 2011Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Hiroaki Ohta, Feng Wu, Anurag Tyagi, Arpan Chakraborty, James S. Speck, Steven P. DenBaars, Shuji Nakamura, Erin C. Young
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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: 20110064106Abstract: A system and method for an electrically pumped laser system is disclosed. The system includes a silicon micro-ring resonator 405. A quantum well 412 formed of a III-V group semiconductor material is optically coupled with the micro-ring resonator 405 to provide optical gain. A trapezoidal shaped buffer 414 formed of a III-V group semiconductor material and doped with a first type of carrier is optically coupled to the quantum well 412. A ring electrode 410 is coupled to the trapezoidal shaped buffer 414. The trapezoidal shaped buffer 414 enables the ring electrode 410 to be substantially isolated from an optical mode of the micro-ring resonator 405.Type: ApplicationFiled: May 6, 2008Publication date: March 17, 2011Inventors: Qianfan Xu, Marco Fiorentino, Raymond G. Beausoleil
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Publication number: 20110058586Abstract: A projection/recess structure is formed on a base substrate, and a layered structure of a nitride semiconductor laser is formed on the projection/recess structure. InGaN used for an active layer has an In intake efficiency and a growth rate that greatly vary with the plane direction. By use of this characteristic, an active layer structure low in In content and small in well layer thickness can be formed at a light-outgoing end facet by one-time crystal growth, and thus the transition wavelength of the active layer near the light-outgoing end facet can be shortened. As a result, since optical damage due to light absorption at the light-outgoing end facet can be greatly reduced, a nitride semiconductor laser capable of performing high light-output operation can be implemented.Type: ApplicationFiled: January 21, 2009Publication date: March 10, 2011Inventors: Toshiyuki Takizawa, Tetsuzo Ueda
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Publication number: 20110032956Abstract: The present invention provides a wide temperature range (WiTR) operating wavelength-narrowed and wavelength-stabilized semiconductor laser having a wide bandwidth gain medium imbedded in a waveguide layer comprising a plurality of quantum dots or quantum wells wherein each quantum dot or quantum well has a different gain peak-wavelength that provides gain at different temperatures as the junction temperature of the laser changes. Therefore, the wavelength defined by an appropriate grating to lock the wavelength and narrow the emission-bandwidth can be realized over a much wider operating temperature range than possible with gain medium that comprises just single quantum well or quantum dot or a plurality of quantum wells or quantum dots that have the same gain peak-wavelength.Type: ApplicationFiled: July 26, 2010Publication date: February 10, 2011Inventor: Manoj Kanskar
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Publication number: 20110007766Abstract: A structure for improving the mirror facet cleaving yield of (Ga,Al,In,B)N laser diodes grown on nonpolar or semipolar (Ga,Al,In,B)N substrates. The structure comprises a nonpolar or semipolar (Ga,Al,In,B)N laser diode including a waveguide core that provides sufficient optical confinement for the device's operation in the absence of p-type doped aluminum-containing waveguide cladding layers, and one of more n-type doped aluminum-containing layers that can be used to assist with facet cleaving along a particular crystallographic plane.Type: ApplicationFiled: July 9, 2010Publication date: January 13, 2011Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Robert M. Farrell, Matthew T. Hardy, Hiroaki Ohta, Steven P. DenBaars, James S. Speck, Shuji Nakamura
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Patent number: 7864828Abstract: A cascade laser device, including a multilayer film structure with a multiple quantum well including a potential barrier and a quantum well; and an electric field applying portion for applying an electric field to the multilayer film structure. The multilayer film structure includes at least two first regions and a second region. The second region is sandwiched between the two first regions; each of the first regions includes multiple sub-bands. When the electric field is applied, carriers are transported from a sub-band in the higher energy quantum well to a sub-band in the lower energy quantum well via the potential barrier in the first regions by tunneling permitted by interaction with light. The second region is thinner than twice a skin depth of the light and includes at least a film having an energy band. The carriers are subjected to energy relaxation in the energy band.Type: GrantFiled: May 29, 2009Date of Patent: January 4, 2011Assignee: Canon Kabushiki KaishaInventor: Ryota Sekiguchi
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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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Patent number: 7856042Abstract: An intersubband quantum cascade laser structure includes multiple coupled laser stages, wherein each stage has a multilayer structure including an electron injector, an active region with at least one quantum well, and an electron reflector. Electrons injected from the injector into the active region at a high energy level relax to a lower energy level with the emission of a photon at, for example, mid-infrared wavelengths. The reflector reflects electrons at the higher energy level at which they were injected and transmits electrons from the lower energy level after emission of a photon. Multiple layers of semiconductor are formed on each side of the multistage structure to provide conduction across the device and to provide optical confinement of the photons emitted.Type: GrantFiled: June 17, 2008Date of Patent: December 21, 2010Assignee: Wisconsin Alumni Research FoundationInventors: Dan Botez, Dapeng P. Xu, Luke J. Mawst
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Publication number: 20100316079Abstract: A vertical cavity surface emitting laser (VCSEL) is described using a sub-wavelength grating (SWG) structure that has a very broad reflection spectrum and very high reflectivity. The grating comprises segments of high and low refractive index materials with an index differential between the high and low index materials. By way of example, a SWG reflective structure is disposed over a low index cavity region and above another reflective layer (either SWG or DBR). In one embodiment, the SWG structure is movable, such as according to MEMS techniques, in relation to the opposing reflector to provide wavelength selective tuning. The SWG-VCSEL design is scalable to form the optical cavities for a range of SWG-VCSELs at different wavelengths, and wavelength ranges.Type: ApplicationFiled: June 7, 2010Publication date: December 16, 2010Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Connie J. Chang-Hasnain, Michael Chung-Yi Huang, Ye Zhou, Carlos Fernando Rondina Mateus
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Patent number: 7839910Abstract: The laser device has a gain medium, first and second clads sandwiching the gain medium in the thickness direction, and a cavity structure for resonating the electromagnetic wave generated in the gain medium. The gain medium includes a plurality of active regions for generating an electromagnetic wave and at lease one connecting region sandwiched among the active regions. The first and second clads are each formed of a negative permittivity medium having a permittivity the real part of which is negative relative to the electromagnetic wave. A potential-adjusting portion is arranged between the connecting region and the first clad and between the connecting region and the second clad for adjusting the electric potential of the connecting region.Type: GrantFiled: December 19, 2008Date of Patent: November 23, 2010Assignee: Canon Kabushiki KaishaInventors: Masahiro Asada, Ryota Sekiguchi, Toshihiko Ouchi