Mode Discrimination Patents (Class 372/19)
  • Patent number: 10411434
    Abstract: The invention relates to a semiconductor structure, including: a semiconductor layer, including a membrane suspended above a carrier layer, the suspended membrane being formed of a central section, which is tensilely stressed and of a plurality of tensioning arms; and least one optical cavity, bounded by two optical reflectors, which are placed in the lateral sections on either side of the central section; wherein: the central section is designed to transmit in the direction of the optical reflectors at least one uneven-order mode; and each of said optical reflectors is formed of two lateral half-reflectors, which are arranged on either side of a longitudinal axis of the lateral section, so as to at least partially reflect said uneven-order mode.
    Type: Grant
    Filed: August 23, 2018
    Date of Patent: September 10, 2019
    Assignee: Commissariat A L'Energie Atomique et aux Energies Alternatives
    Inventors: Vincent Reboud, Salim Boutami
  • Patent number: 10396528
    Abstract: Provided is a laser device according to an embodiment of the inventive concept. The laser device includes: a semiconductor substrate; a germanium single crystal layer on the semiconductor substrate; and a pumping light source disposed on the germanium single crystal layer and configured to emit light toward the germanium single crystal layer, wherein the germanium single crystal layer receives the light to thereby output laser.
    Type: Grant
    Filed: July 9, 2018
    Date of Patent: August 27, 2019
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: In Gyoo Kim, Gyungock Kim, Sang Hoon Kim
  • Patent number: 10360922
    Abstract: A noise reduction device includes an acoustic characteristic determination unit, a microphone pair selection unit, and a noise reduction unit. The acoustic characteristic determination unit determines, using one of microphone pair signals obtained from a plurality of microphone pairs, whether acoustic characteristics of each of the plurality of microphone pairs satisfy a certain requirement. The microphone pair selection unit selects, from among the plurality of microphone pairs, a target microphone pair whose acoustic characteristics have been determined to satisfy the certain requirement. The noise reduction unit reduces, using a microphone pair signal obtained from the target microphone pair, noise included in an input signal obtained from at least one of microphone signals output from a plurality of microphones.
    Type: Grant
    Filed: September 13, 2017
    Date of Patent: July 23, 2019
    Assignee: PANASONIC CORPORATION
    Inventors: Tsuyoki Nishikawa, Kohhei Hayashida
  • Patent number: 10236662
    Abstract: The teachings herein disclose a laser assembly (20) that implements a “composite cavity” formed in part in a III/V die (22), in part in a silicon die (26), and in part in a glass member (24) having a waveguide (44) coupling the cavity portion in the III/V die with the cavity portion in the silicon die. This arrangement capitalizes on the lasing efficiency of the III/V die, which is used as the gain medium while advantageously using the glass member to extend the lasing cavity into the silicon die. Laser-scribing the cavity waveguide in place after mounting the III/V die, the silicon die or dies, and the glass member, greatly relaxes the mounting alignment precision needed for the constituent parts of the overall assembly. Moreover, in one or more embodiments, glass member includes one or more laser-scribed waveguides operative as optical interconnects going between two or more silicon dies.
    Type: Grant
    Filed: November 11, 2015
    Date of Patent: March 19, 2019
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Mehrdad Mir Shafiei, Robert Brunner, Stephane Lessard
  • Patent number: 10224689
    Abstract: A Q-switched CO2 laser material processing system with acousto-optic modulators (AOM) is employed, on the one hand, inside the resonator for Q-switching the CO2 laser and, on the other hand, externally for efficient suppression of the radiation feedback between a laser and workpiece. The frequency shift of the radiation diffracted at the AOM is taken into account which exactly corresponds to the excitation frequency of the acoustic wave in the AOM crystal under the aspect of the amplification of the radiation in the active medium. Since this frequency shift significantly reduces the amplification of the radiation, it has to be avoided in the Q-switching process, which is achieved, by means of a tandem of two AOMs with identical excitation frequencies but with the acoustic waves propagating in opposite directions in the crystal. The frequency shift advantageously suppresses radiation feedback between the laser and workpiece.
    Type: Grant
    Filed: July 22, 2015
    Date of Patent: March 5, 2019
    Assignee: FEHA LASERTEC GMBH
    Inventor: Gisbert Staupendahl
  • Patent number: 10190970
    Abstract: The present invention relates to a sensor using a tilted fiber grating to detect physical manifestations occurring in a medium. Such physical manifestations induce measurable changes in the optical property of the tilted fiber grating. The sensor comprises a sensing surface which is to be exposed to the medium, an optical pathway and a tilted grating in the optical pathway. The grating is responsive to electromagnetic radiation propagating in the optical pathway to generate a response conveying information on the physical manifestation.
    Type: Grant
    Filed: November 28, 2017
    Date of Patent: January 29, 2019
    Assignee: WEATHERFORD CANADA LTD
    Inventors: Jacques Albert, Chengkun Chen, Yanina Shevchenko, Alexei Ivanov
  • Patent number: 10193297
    Abstract: A laser system involving coupled distributed resonators disposed serially, with the lasing gain medium located in the main resonator and the output of that resonator being directed into a free space resonator, such that the main resonator output mirror is effectively the free space resonator. The distributed resonators end mirrors are retroreflectors. Interference occurs between light traveling towards the remote mirror of the free space resonator and light reflected therefrom, generating regions of high reflectivity. The coupling of the free space resonator to the regions of high reflectivity of the free space resonator enables the first resonator to lase efficiently, even though the true reflectivity of the main resonator output mirror outside of those regions is insufficient to enable efficient lasing, if at all. This coupled resonator structure enables lasing to occur with a high field of view and the high gain engendered by the high reflectivity regions.
    Type: Grant
    Filed: February 2, 2016
    Date of Patent: January 29, 2019
    Assignee: Wi-Charge Ltd.
    Inventors: Ortal Alpert, Eitan Ronen, Omer Nahmias, Ori Refael Mor, Lior Golan, Ran Sagi
  • Patent number: 10193305
    Abstract: A wavelength tunable laser device includes: a laser cavity formed of a grating and a reflecting mirror including a ring resonator filter; a gain portion; and a phase adjusting portion. The grating creates a first comb-shaped reflection spectrum. The ring resonator filter includes a ring-shaped waveguide and two arms and creates a second comb-shaped reflection spectrum having peaks of a narrower full width than peaks in the first comb-shaped reflection spectrum at a wavelength interval different from that of the first comb-shaped reflection spectrum. One of the peaks in the first comb-shaped reflection spectrum and one of the peaks in the second comb-shaped reflection spectrum are overlapped on a wavelength axis, and a spacing between cavity modes is narrower than the full width at half maximum of the peaks in the first comb-shaped reflection spectrum.
    Type: Grant
    Filed: September 19, 2017
    Date of Patent: January 29, 2019
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Yasumasa Kawakita, Yasutaka Higa, Norihiro Iwai, Tatsuro Kurobe
  • Patent number: 10165665
    Abstract: A laser beam having desired properties is output at desired timings. A laser apparatus is a laser apparatus for use with an extreme ultraviolet light generating apparatus that generates extreme ultraviolet light at a repetition frequency which is set in advance, and may be equipped with: a semiconductor laser that outputs a laser beam when a trigger signal is input thereto; an optical switch that switches between a state in which the laser beam passes therethrough and a state in which the laser beam does not pass therethrough, provided along the optical path of the laser beam; and a control unit configured to output the trigger signal to the semiconductor laser at a frequency which is an integer multiple of the repetition frequency, and to control the optical switch such that the laser beam passes therethrough at the repetition frequency.
    Type: Grant
    Filed: March 9, 2017
    Date of Patent: December 25, 2018
    Assignee: Gigaphoton Inc.
    Inventor: Seiji Nogiwa
  • Patent number: 10116113
    Abstract: There are provided: a planar waveguide in which claddings (2) and (3) each having a smaller refractive index than a laser medium for absorbing pump light (5) are bonded to an upper surface (1a) and a lower surface (1b) of a core (1) which is formed from the laser medium; pump light generation sources (4a) and (4b) for emitting pump light (5) to side surfaces (1c) and (1d) of the core (1); and laser light high reflection films (6a) and (6b) formed on side surfaces (1e) and (1f) of the core (1). Each of side surfaces (2e) and (2f) of the cladding (2) corresponding to the side surfaces (1e) and (1f) of the core (1) has a ridge structure (20) in which a part thereof is recessed.
    Type: Grant
    Filed: August 7, 2015
    Date of Patent: October 30, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takeshi Sakimura, Yuhi Kono, Kohei Sakai, Yukari Takada, Yojiro Watanabe, Fumio Shoda, Takayuki Yanagisawa
  • Patent number: 10043946
    Abstract: A method of fabricating LEDs from a wafer comprising a substrate and epitaxial layers and having a substrate side and a epitaxial side, said method comprising: (a) applying a laser beam across at least one of said substrate side or said epitaxial side of said wafer to define at least one laser-scribed recess having a laser-machined surface; and (b) singulating said wafer along said laser-scribed recess to form singulated LEDs, said singulated LEDs having a top surface, a bottom surface, and a plurality of sidewalls, at least one of said sidewalls comprising at least a first portion comprising at least a portion of said laser-machined surface.
    Type: Grant
    Filed: August 2, 2016
    Date of Patent: August 7, 2018
    Assignee: Soraa, Inc.
    Inventors: Rafael Aldaz, Aurelien J. F. David, Daniel F. Feezell, Thomas M. Katona, Rajat Sharma, Michael J. Cich
  • Patent number: 9973283
    Abstract: An optical coupling system includes an optical signal source to provide an optical signal from an aperture. The system also includes a substantially planar high-contrast grating (HCG) lens to convert an optical mode of the optical signal to provide a converted optical signal having a mode-isolating intensity profile. The system further includes an optical element to receive the converted optical signal. The optical signal source and the substantially planar HCG lens can be arranged to substantially mitigate coupling of a reflected optical signal associated with the converted optical signal that is reflected from the optical element to the aperture of the optical signal source based on a reflected mode-isolating intensity profile.
    Type: Grant
    Filed: April 11, 2013
    Date of Patent: May 15, 2018
    Assignee: Hewlett Packard Enterprise Development LP
    Inventors: Wayne Victor Sorin, Sonny Vo, David A. Fattal, Michael Renne Ty Tan
  • Patent number: 9819147
    Abstract: A method to tune an emission wavelength of a wavelength tunable laser apparatus is disclosed. The laser apparatus implements, in addition to a wavelength tunable laser diode (t-LD) integrating with a semiconductor optical amplifier (SOA), a wavelength monitor including an etalon filter. The current emission wavelength is determined by a ratio of the magnitude of a filtered beam passing the etalon filter to a raw beam not passing the etalon filter. The method first sets the SOA in an absorbing mode to sense stray component disturbing the wavelength monitor, then correct the ratio of the beams by subtracting the contribution from the stray component.
    Type: Grant
    Filed: August 19, 2015
    Date of Patent: November 14, 2017
    Assignee: Sumitomo Electric Device Innovations, Inc.
    Inventors: Hirokazu Tanaka, Tetsufumi Odagawa, Hiromitsu Kawamura, Masao Shibata
  • Patent number: 9806498
    Abstract: A vertical-cavity surface-emitting laser diode includes: a first resonator that has a plurality of semiconductor layers comprising a first current narrowing structure having a first conductive region and a first non-conductor region; a first electrode that supplies electric power to drive the first resonator; a second resonator that has a plurality of semiconductor layers comprising a second current narrowing structure having a second conductive region and a second non-conductive region and that is formed side by side with the first resonator, the second current narrowing structure being formed in same current narrowing layer as the layer where the first current narrowing structure is formed; and a coupling portion as defined herein; and an equivalent refractive index of the coupling portion is smaller than an equivalent refractive index of each of the first resonator and the second resonator.
    Type: Grant
    Filed: May 2, 2016
    Date of Patent: October 31, 2017
    Assignees: TOKYO INSTITUTE OF TECHNOLOGY, FUJI XEROX CO., LTD.
    Inventors: Fumio Koyama, Hamed Dalir, Takashi Kondo, Naoki Jogan, Kazutaka Takeda, Hideo Nakayama
  • Patent number: 9689603
    Abstract: A refrigerator includes a body including a storage chamber; a door that is coupled to the body so as to open/close the storage chamber; a display that is disposed in at least one region of the door and is configured to be converted between a transparent mode and a display mode; and a controller that controls the display to display at least one among a text, an image, and color when the display is in the display mode.
    Type: Grant
    Filed: March 30, 2015
    Date of Patent: June 27, 2017
    Assignees: SAMSUNG ELECTRONICS CO., LTD., NDIS CORPORATION
    Inventors: Hee Yuel Roh, Soon-Bum Kwon, Kyoung Sun Kim, Joo Ho Kim, Otsuka Tatsuhiro, Burm-Young Lee
  • Patent number: 9685756
    Abstract: There may be provided a laser amplifier including: a chamber containing a laser medium; a first window provided on the chamber, and configured to allow a laser light beam inputted from outside of the chamber to enter the chamber; an excitation unit configured to amplify, by exciting the laser medium, the laser light beam that has entered the chamber; a second window provided on the chamber, and configured to allow the laser light beam that has been amplified by the excitation unit to exit from the chamber to the outside; a mirror provided on a laser light path between the first window and the second window; and a wavelength selection film provided on one or more of the first window, the second window, and the mirror, and configured to suppress propagation of light beams of one or more suppression target wavelengths different from a desired wavelength.
    Type: Grant
    Filed: February 10, 2016
    Date of Patent: June 20, 2017
    Assignee: GIGAPHOTON INC.
    Inventors: Takashi Suganuma, Hideo Hoshino
  • Patent number: 9653882
    Abstract: An optical source is described. This hybrid external cavity laser includes a semiconductor optical amplifier (with a semiconductor other than silicon) that provides an optical gain medium and that includes a reflector (such as a mirror). Moreover, the hybrid external cavity laser includes a photonic chip with: an optical waveguide that conveys an optical signal output by the semiconductor optical amplifier; and a ring resonator (as a wavelength-selective filter), having a resonance wavelength, which reflects at least a resonance wavelength in the optical signal. Furthermore, the photonic chip includes an interferometer that provides optical signals on arms of the interferometer. Control logic in the hybrid external cavity laser thermally tunes the resonance wavelength to match a cavity mode of the hybrid external cavity laser based on measurements of the optical signals from the interferometer.
    Type: Grant
    Filed: February 9, 2016
    Date of Patent: May 16, 2017
    Assignee: ORACLE AMERICA, INC.
    Inventors: Xuezhe Zheng, Daniel Y. Lee, Ashok V. Krishnamoorthy
  • Patent number: 9500781
    Abstract: An optical system and a laser processing apparatus with which spattering can be suppressed by reducing an evaporation reactive force at a workpiece by forming two focal points on the optical axis, using a simple configuration. The optical system is provided with a convex lens that focuses laser light; and a concave lens that is disposed on the same optical axis as the laser light that passes through the convex lens. The concave lens has a first region that has a through-hole, that is positioned on the optical axis, and that does not have lens properties, as well as a second region that surrounds the first region and that diverges the laser light.
    Type: Grant
    Filed: August 7, 2013
    Date of Patent: November 22, 2016
    Assignee: MITSUBISHI HEAVY INDUSTRIES, LTD.
    Inventor: Masao Watanabe
  • Patent number: 9484707
    Abstract: Optical fibers that provide stable output beam sizes have core refractive indices that decrease non-monotonically from a core center to a core/cladding interface. A maximum refractive index of the core is situated at a radius of between about ½ and ¾ of the core radius so that a core center has a depressed refractive index. Such fibers are included in diode pumped solid state lasers to deliver pump laser power to a laser medium.
    Type: Grant
    Filed: December 30, 2013
    Date of Patent: November 1, 2016
    Assignee: nLIGHT, Inc.
    Inventors: Jay Small, Ken Gross, Shuang Li
  • Patent number: 9403237
    Abstract: A monolithic resonator that has a plurality of mode families is modified so that portions of the resonator have a different index of refraction than other portions of the resonator. This degrades the Q factor of one or more of the mode families, allowing pre-selection of one or more mode families over others.
    Type: Grant
    Filed: March 12, 2014
    Date of Patent: August 2, 2016
    Assignee: Oewaves, Inc.
    Inventors: Lute Maleki, Andrey Matsko, Anatoliy A. Savchenkov, Iouri Solomatine
  • Patent number: 9341757
    Abstract: An optical component including an interference filter which is less likely to generate back reflected light, where the filter is accommodated in a hollow cylindrical housing and is tilted with respect to the optical axis. The housing has front and back openings. First and second collimator lenses respectively face the front and back openings. The housing includes a filter housing section and first and second cylindrical optical path sections extending in the front-back direction respectively from the front and back openings to the filter housing section while maintaining the shape of each opening. The diameter of the opening of the first optical path section is smaller than the apparent diameter of the first collimator lens. When light is input from the front along the optical axis, light of prescribed wavelengths is output to the back. Light reflected by the filter travels toward the inside of the first optical path section.
    Type: Grant
    Filed: October 30, 2012
    Date of Patent: May 17, 2016
    Assignee: Kohoku Kogyo Co., Ltd.
    Inventors: Takashi Kato, Tomoaki Kiriyama
  • Patent number: 9225147
    Abstract: An optical semiconductor device includes a semiconductor substrate; a lower cladding layer formed over the semiconductor substrate; a quantum well active layer formed on the lower cladding layer; a diffraction grating layer formed over the quantum well active layer and having diffraction gratings formed in a surface thereof; and an upper cladding layer formed on the diffraction gratings of the diffraction grating layer. Further, a band gap in outer regions of the quantum well active layer that are adjacent to outer end surfaces of the optical semiconductor device is greater than the band gap in an inner region of the quantum well active layer that is located between the outer regions, and a thickness of one or more layers, which include the lower cladding layer and positioned between the semiconductor substrate and the quantum well active layer, is greater than or equal to 2.3 ?m.
    Type: Grant
    Filed: July 17, 2013
    Date of Patent: December 29, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Akinori Hayakawa, Takeshi Matsumoto
  • Patent number: 9219349
    Abstract: A surface emitting semiconductor laser includes: a substrate; a first semiconductor multilayer reflector on the substrate including laminated pairs of a high refractive index layer relatively high in refractive index and a low refractive index layer relatively low in refractive index; an active region on or above the first reflector; a second semiconductor multilayer reflector on or above the active region including laminated pairs of a high refractive index layer relatively high in refractive index and a low refractive index layer relatively low in refractive index; and a cavity extending region formed between the first reflector and the active region or between the second reflector and the active region, having an optical film thickness greater than an oscillation wavelength, extending a cavity length, including a conductive semiconductor material, and including an optical loss causing layer at at least one node of a standing wave of a selected longitudinal mode.
    Type: Grant
    Filed: May 6, 2013
    Date of Patent: December 22, 2015
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Kazutaka Takeda, Takashi Kondo
  • Patent number: 9197029
    Abstract: In a laser device, a control range of focal distance of a generated thermal lens is broadened and reliability is improved. A mode control waveguide-type laser device includes: a planar laser medium having a waveguide structure in a thickness direction of a cross section perpendicular to an optical axis, for generating gain with respect to laser light; a cladding bonded onto the laser medium; and a heat sink bonded onto the laser medium. The laser medium generates a lens effect, and the laser light oscillates in a waveguide mode in the thickness direction, and oscillates in a spatial mode due to the lens effect in a direction perpendicular to the optical axis and the thickness direction. The refractive index distribution within the laser medium is created by generating a temperature distribution in the laser medium depending on a junction area of the cladding and the heat sink.
    Type: Grant
    Filed: December 21, 2010
    Date of Patent: November 24, 2015
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Noriyuki Miyamoto, Shuhei Yamamoto, Takayuki Yanagisawa, Yoshihito Hirano
  • Patent number: 9074853
    Abstract: A high-energy laser system intercepting a target using a phase conjugate mirror includes a laser oscillator which generates a laser beam irradiated to the target, a light amplifier which receives the laser beam irradiated to and reflected by the target so as to amplify it, a phase conjugate mirror which reflects the amplified laser beam. And the laser beam that is reflected by the phase conjugate mirror is amplified again in the light amplifier, and then irradiated to the target so as to intercept the target.
    Type: Grant
    Filed: September 10, 2010
    Date of Patent: July 7, 2015
    Assignee: KOREA ADVANCED INSTITUTE OF SCIENCE AND TECHNOLOGY
    Inventors: Hong Jin Kong, Jae Sung Shin, Sang Woo Park, Kang Sup Shim, Seong Woo Cha
  • Patent number: 9036668
    Abstract: A method for quasi-synchronous tuning of wavelength or frequency of grating external-cavity semiconductor laser and a corresponding semiconductor laser are provided. A grating or mirror is rotated around a quasi-synchronous tuning point (Pq) as rotation center, so as to achieve the frequency selections by grating and resonance cavity in quasi-synchronous tuning, wherein the angle of the line between the quasi-synchronous tuning point (Pq) and a conventional synchronous tuning point (P0) with respect to the direction of light incident on the grating is determined according to the angle difference between the incidence angle and diffraction angle of light on the grating. According to present invention, approximately synchronous tuning of laser is achieved with a simple and flexible design.
    Type: Grant
    Filed: June 10, 2009
    Date of Patent: May 19, 2015
    Assignee: NATIONAL INSTITUTE OF METROLOGY P.R. CHINA
    Inventors: Erjun Zang, Jianping Cao, Ye Li, Zhanjun Fang
  • Patent number: 9025626
    Abstract: A semiconductor laser excited solid state laser device and method. The device including a semiconductor laser; a driving device; a solid state laser module which has maximum output efficiency at the set temperature and which generates, from excitation light, an output light of a predetermined output level when the optical noise is at or below a fixed level and the output level of the excitation light is the set output level; a single temperature adjustment device which adjusts the temperature of the semiconductor laser and the temperature of the solid state laser module; and a control device which controls the driving device such that the output light will be at the predetermined output level and controls the temperature adjustment device such that the temperature of the semiconductor laser and the solid state laser module will be the set temperature.
    Type: Grant
    Filed: September 19, 2013
    Date of Patent: May 5, 2015
    Assignee: Shimadzu Corporation
    Inventors: Kazutomo Kadokura, Katsuhiko Tokuda, Mamoru Hisamitsu, Kazuya Inoue
  • Patent number: 9014222
    Abstract: A discretely tunable laser device is provided. The discretely tunable laser device comprises: a laser comprising a plurality of discrete output modes; an optical filter for receiving output from the laser but otherwise optically isolated from the laser, the optical filter comprising a plurality of transmission peaks, each separated by a transmission spacing different from a spacing of the plurality of discrete output modes such that only one discrete output mode can predominantly align with one transmission peak when the plurality of discrete output modes are tuned; and, a control apparatus for tuning the discrete output modes of the laser to align a given output mode of the plurality of discrete output modes with a given transmission peak of the plurality of transmission peaks, such that the given output mode comprises a dominant output of the optical filter.
    Type: Grant
    Filed: August 15, 2012
    Date of Patent: April 21, 2015
    Assignee: Ranovus Inc.
    Inventor: Douglas J. S. Beckett
  • Publication number: 20150078407
    Abstract: A semiconductor laser excited solid state laser device and method. The device including a semiconductor laser; a driving device; a solid state laser module which has maximum output efficiency at the set temperature and which generates, from excitation light, an output light of a predetermined output level when the optical noise is at or below a fixed level and the output level of the excitation light is the set output level; a single temperature adjustment device which adjusts the temperature of the semiconductor laser and the temperature of the solid state laser module; and a control device which controls the driving device such that the output light will be at the predetermined output level and controls the temperature adjustment device such that the temperature of the semiconductor laser and the solid state laser module will be the set temperature.
    Type: Application
    Filed: September 19, 2013
    Publication date: March 19, 2015
    Applicant: SHIMADZU CORPORATION
    Inventors: Kazutomo KADOKURA, Katsuhiko TOKUDA, Mamoru HISAMITSU, Kazuya INOUE
  • Patent number: 8982916
    Abstract: A method for producing an externally injected gain switch laser ultrashort pulse, comprising the following steps of ultrashort light pulse signals having multi-longitudinal mode characteristic produced by the gain switch laser are inputted into an optical amplifier and then amplified; a spectral component signal selector selects a narrow spectral component signal outputted by the optical amplifier, the narrow spectral component signal is within an amplified spontaneous emission noise frequency band and its central wavelength is equal to the longitudinal mode of the gain switch laser; a route of the narrow spectral component signal is used as an external seed light and reinjected into the gain switch laser via a spectral component signal feedback loop. Therefore, the oscillation of a selected single longitudinal mode within the cavity of the gain switch laser is enhanced, thereby forming an externally light injected locking.
    Type: Grant
    Filed: August 8, 2007
    Date of Patent: March 17, 2015
    Assignee: Xi'an Institute of Optics and Precision Mechanics of Chinese Academy of Sciences
    Inventors: Jianguo Zhang, Wei Zhao, Yuanshan Liu
  • Patent number: 8976831
    Abstract: An edge emitting semiconductor laser comprising an active, radiation-generating zone (1), and an common waveguide (8), which is suitable for guiding the radiation generated in the active zone (1) within the semiconductor laser. The common waveguide (8) comprises a first n-doped layer (4) and a second n-doped layer (5), which is arranged between the first n-doped layer (4) and the active zone (1), wherein the refractive index n2 of the second n-doped layer (5) is greater than the refractive index n1 of the first n-doped layer (4) by a value dn.
    Type: Grant
    Filed: March 12, 2014
    Date of Patent: March 10, 2015
    Assignee: OSRAM Opto Semiconductors GmbH
    Inventors: Alvaro Gomez-Iglesias, Guenther Groenninger, Christian Lauer, Harald Koenig
  • Patent number: 8953649
    Abstract: A method for quasi-synchronous tuning of wavelength or frequency of grating external-cavity semiconductor laser and a corresponding semiconductor laser are provided. A grating or mirror is rotated around a quasi-synchronous tuning point (Pq) as rotation center, so as to achieve the frequency selections by grating and resonance cavity in quasi-synchronous tuning, wherein the angle of the line between the quasi-synchronous tuning point (Pq) and a conventional synchronous tuning point (P0) with respect to the direction of light incident on the grating is determined according to the angle difference between the incidence angle and diffraction angle of light on the grating. According to present invention, approximately synchronous tuning of laser is achieved with a simple and flexible design.
    Type: Grant
    Filed: January 15, 2014
    Date of Patent: February 10, 2015
    Assignee: National Institute of Metrology P.R. China
    Inventors: Erjun Zang, Jianping Cao, Ye Li, Zhanjun Fang
  • Patent number: 8942976
    Abstract: The present invention provides a noise reduction control method using a microphone array and a noise reduction control device using a microphone array wherein the method comprises the steps of: S1: collecting, by the microphone array, acoustic signals; S2: estimating incidence angles of all acoustic signals of the microphone array; S3: conducting a statistics on signal components according to incidence angles; S4: determining a parameter ? from a ratio of noise components according to the statistical result and using the parameter ? as a control parameter for controlling an adaptive filter. With the present invention, space position information of the sound is obtained directly with the microphone array to control update of the adaptive filter more accurately, so as to eliminate noise, enhance SNR and protect speech quality well at the same time.
    Type: Grant
    Filed: December 15, 2010
    Date of Patent: January 27, 2015
    Assignee: Goertek Inc.
    Inventors: Bo Li, Shasha Lou, Song Li
  • Patent number: 8897332
    Abstract: A laser cavity structure is disclosed which pertains to laser resonator geometries possessing circular symmetry, such as in the case of disk or spherical lasers. The disclosed invention utilizes a very-high finesse Bragg reflector (VHF-BR) thin film reflectors of many layer pairs of very small refractive index difference, the VHF-BR deposited on a surface of revolution, thereby forming an optical cavity. These dielectric reflectors are disposed in such a way as to allow selection of preferred low order modes and suppression of parasitic modes while allowing a high cavity Q factor for preferred modes. The invention disclosed, in its preferred embodiments, is seen as particularly useful in applications requiring high efficiency in the production and coupling of coherent radiation. This is accomplished in a cavity design that is relatively compact and economical.
    Type: Grant
    Filed: March 14, 2011
    Date of Patent: November 25, 2014
    Inventor: Donald B Hilliard
  • Publication number: 20140321485
    Abstract: An external cavity laser comprises a gain medium and an external cavity resonator without the use of a semi-reflective surface placed between the gain medium and the resonator. Radiation from the gain medium is reflected back to the gain medium by one or more resonant backscattering regions of the resonator, such that the entire optical path between the gain medium and the external cavity resonator could be free from a reflective surface.
    Type: Application
    Filed: April 25, 2014
    Publication date: October 30, 2014
    Applicant: OEwaves, Inc.
    Inventors: David J. Seidel, Elijah B. Dale, Andrey B. Matsko, Lute Maleki
  • Patent number: 8867577
    Abstract: A laser light source according to the present invention includes a laser element that outputs a fundamental wave; a wavelength conversion element into which the fundamental wave is input and that converts at least a part of the fundamental wave input therein to a converted wave having a wavelength shorter than the wavelength of the fundamental wave; a waveguide that attenuates a component of the fundamental wave included in an output wave from the wavelength conversion element; and a diffraction grating that is formed on the waveguide and feeds back the fundamental wave output from the wavelength conversion element to lock the wavelength or the frequency of the fundamental wave output from the laser element. The diffraction grating is formed at a position determined taking into account an amount by which the fundamental wave is attenuated in the waveguide.
    Type: Grant
    Filed: December 20, 2012
    Date of Patent: October 21, 2014
    Assignee: Citizen Holdings Co., Ltd.
    Inventors: Shinpei Fukaya, Masafumi Ide
  • Publication number: 20140307751
    Abstract: A laser processing apparatus including a laser oscillator, a laser processing machine, and a control part controlling the laser oscillator and the laser processing machine. The control part includes a preparatory operation part controlling the laser processing machine so as to start a preparatory operation for the laser processing if a preparatory operation command is output and, a mode switching part switching an operating mode of the laser oscillator between a standard standby mode before carrying out the laser processing and an energy saving mode with less consumed power than the standard standby mode, and the mode switching part controls the discharge tube voltage so as to switch the operating mode to the energy saving mode before the preparatory operation command is output and to start a switching operation of the operating mode from the energy saving mode to the standard standby mode when the preparatory operation command is output.
    Type: Application
    Filed: April 10, 2014
    Publication date: October 16, 2014
    Applicant: FANUC CORPORATION
    Inventor: Ryusuke Miyata
  • Patent number: 8786940
    Abstract: An apparatus and method that reduces laser speckle by using stimulated Raman scattering in an optical fiber. The fiber core diameter and length are selected to achieve a desired output color. An adjustable despeckler is formed by combining two optical fibers in parallel and adjusting the amount of light in each path.
    Type: Grant
    Filed: December 7, 2010
    Date of Patent: July 22, 2014
    Assignee: Laser Light Engines, Inc.
    Inventors: Barret Lippey, William Beck, Ian Turner
  • Patent number: 8774242
    Abstract: A surface emitting laser diode comprises a substrate, a lower reflector formed over the substrate, an active layer formed over the lower reflector, an upper reflector formed over the active layer, a current restrict structure including a current confinement region surrounded by insulation region. The current restrict structure is disposed in an upper reflector or between an active layer and the upper reflector, and an upper electrode formed over the upper reflector includes an aperture which corresponds to an emission region from which light is emitted in a first direction perpendicular to a surface of a substrate. The emission region and the current restrict structure including the current confinement region are selectively configured to obtain high single transverse mode, stabilized polarization direction, isotropic beam cross section and small divergence angle, while allowing the device to be manufactured with high yield rate.
    Type: Grant
    Filed: May 8, 2012
    Date of Patent: July 8, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiro Itoh, Kazuhiro Harasaka, Shunichi Sato, Naoto Jikutani
  • Patent number: 8761217
    Abstract: A system includes a modulatable source and matched modal filter. The modulatable source is associated with a plurality of source modes to provide a generated signal. The matched modal filter is coupled to the modulatable source to receive the generated signal. Filter modes are to match the source modes. The matched modal filter is coupleable to a link fiber to provide a signal to the link fiber. The filter modes are to match a subset of link fiber modes to couple the plurality of filter modes to the link fiber.
    Type: Grant
    Filed: April 6, 2012
    Date of Patent: June 24, 2014
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Michael Renne Ty Tan, Shih-Yuan Wang, Wayne Victor Sorin
  • Patent number: 8681825
    Abstract: A method for quasi-synchronous tuning of laser wavelength or frequency of grating external-cavity laser and a corresponding laser are provided. A grating or mirror is rotated around a quasi-synchronous tuning point (Pq) to achieve the quasi-synchronous tuning of frequency selections by grating and resonance cavity, wherein, on the xOy coordinate plane, from the perspective of actual physical space of the laser, the rotation center Pq(xq, yq) satisfying the quasi-synchronous tuning condition can be considered as being extended from the rotation center P0(x0, y0) under the conventional synchronous tuning condition to the region enclosed by two parabolas near P0. According to the present disclosure, approximately-synchronous tuning of laser is achieved with simple and flexible designs.
    Type: Grant
    Filed: July 22, 2011
    Date of Patent: March 25, 2014
    Assignee: National Institute of Metrology Peoples Republic of China
    Inventors: Shaokai Wang, Erjun Zang, Ye Li, Jianping Cao, Zhanjun Fang
  • Patent number: 8675695
    Abstract: An apparatus comprising: a processor for determining if a laser is operating in a single-mode state and for determining the degree to which one of one or more tunable parameters for the laser must be adjusted so that laser operates in a single-mode state if not operating in a single-mode state, wherein the one or more tunable parameters include the following parameters: the laser current and the wavelength of the output light. The apparatus may include a laser and/or a holographic storage medium. Also provided is a method for determining if a laser is operating in a single-mode state and for determining the degree to which one of one or more tunable parameters for the laser must be adjusted so that laser operates in a single-mode state if not operating in a single-mode state.
    Type: Grant
    Filed: July 25, 2012
    Date of Patent: March 18, 2014
    Assignee: Akonia Holographics, LLC
    Inventors: Paul C. Smith, Jason R. Ensher, Paul A. Morrison, Keith W. Malang, Roger Shepherd, William G. Creech
  • Patent number: 8649086
    Abstract: An enhancement cavity includes a plurality of focusing mirrors, at least one of which defines a central aperture having a diameter greater than 1 mm. The mirrors are configured to form an optical pathway for closed reflection and transmission of the optical pulse within the enhancement cavity. Ring-shaped optical pulses having a peak intensity at a radius greater than 0.5 mm from a central axis are directed into the enhancement cavity. Accordingly, the peak intensity of the optical pulse is distributed so as to circumscribe the central apertures in the apertured mirrors, and the mirrors are structured to focus the pulse about the aperture toward a central spot area where the pulse is focused to a high intensity.
    Type: Grant
    Filed: September 30, 2010
    Date of Patent: February 11, 2014
    Assignee: Massachusetts Institute of Technology
    Inventors: Franz X. Kartner, Gilberto Abram, William P. Putnam, Shu-Wei Huang, Edilson L. Falcao-Filho
  • Publication number: 20130336663
    Abstract: A driver circuit configured to generate a drive signal for an optical source comprises an overshoot controller that provides an amount of overshoot for a given logic state of the drive signal as a function of a duration of at least one previous logic state of the drive signal. The drive signal may alternate between a first logic state associated with a first operating mode of the optical source and a second logic state associated with a second operating mode of the optical source. The overshoot controller may be configured to provide amounts of overshoot for respective instances of the first logic state that are proportional to the durations of their respective immediately preceding second logic states. The driver circuit may be implemented in a heat-assisted magnetic recording system in which the optical source alternates between on and off states associated with respective magnetic write and magnetic read modes.
    Type: Application
    Filed: June 18, 2012
    Publication date: December 19, 2013
    Applicant: LSI Corporation
    Inventors: Jason P. Brenden, Xuemin Yang, Cameron C. Rabe
  • Publication number: 20130322471
    Abstract: A laser resonator is provided that includes a cavity bounded by an end mirror and output coupler, and one or more gain media between the end mirror and output coupler. The laser resonator also includes a modal corrector mirror between the end mirror and output coupler. The modal corrector mirror includes a controllable-profile faceplate including an optically-treated front surface, and an array of static actuators. Each static actuator includes an adjustable element, and a compliant mechanism located between the adjustable element and faceplate. The adjustable element is configured to exert a selectable, localized push-pull force on the faceplate via the compliant mechanism, and the compliant mechanism is configured to scale the respective force.
    Type: Application
    Filed: June 4, 2012
    Publication date: December 5, 2013
    Applicant: The Boeing Company
    Inventor: Dennis Rossbach
  • Patent number: 8451871
    Abstract: The method of the invention is intended for manufacturing a laser diode with improved light-emitting characteristics. The method consists of providing certain components of a laser diode such as a wide-aperture lasing medium that has an active emitting layer with a first end and a second end, a DPH-mode reorganizer that contains a core and a plurality of nanogrooves made in the core and arranged in a pattern that accomplishes a given function and locally changes the refractive index of the core. The method further includes the steps of forming a semitransparent mirror on the second end of the active lasing medium and aligning the first end of the active emitting layer with the core of the DPH-mode reorganizer, thus forming a resonator of the laser diode. In the resonator, the light applied from the laser-active medium bounces back and forth between the DPH-mode reorganizer and the partially reflecting mirror, thereby enhancing stimulated emission.
    Type: Grant
    Filed: June 27, 2011
    Date of Patent: May 28, 2013
    Inventor: Vladimir Yankov
  • Patent number: 8416831
    Abstract: The invention relates to a laser light source for generating narrow-band laser radiation with high coherence, comprising a laser diode (1), which forms an internal resonator (4), and an external resonator (7) coupled to the internal resonator (4). The object of the invention is to improve a laser source of the kind such that it generates narrow-band and coherent laser radiation with high output power and at the same time with high long-term stability. Furthermore, the laser light source is to be produced in a cost-effective manner. The object is achieved by the invention in that the laser diode (1) runs in an operating mode in which multimode laser radiation is generated, comprising a plurality of spectrally neighboring resonance modes (9) of the external resonator (7). The resonance modes are selected by adapting the spectral characteristics of the external (7) and internal (4) resonators.
    Type: Grant
    Filed: December 18, 2007
    Date of Patent: April 9, 2013
    Assignee: TOPTICA Photonics AG
    Inventors: Thomas Heine, Frank Lison, Anselm Deninger
  • Patent number: 8385376
    Abstract: The invention relates to a laser source with an external cavity generating a useful laser beam (Fu), that comprises at least one laser diode DL (10) mounted in an extended optical cavity (30, 82) defined between two reflecting surfaces (92, 48) forming an optical path for a laser beam Fd generated by the laser diode DL, a mode selection filter (44, 86) in the optical path of the cavity for selecting a resonance mode from a range of resonance modes of the laser beam in the cavity.
    Type: Grant
    Filed: April 24, 2008
    Date of Patent: February 26, 2013
    Assignees: Thales and Centre National d'Etudes Spatiales, Observatoire de Paris
    Inventors: David Holleville, Noel Dimarcq
  • Patent number: 8374205
    Abstract: Provided is a vertical cavity surface emitting laser that includes a plurality of laminated semiconductor layers including an active layer and that oscillates at a wavelength ?1, wherein a resonator is formed by upper and lower multilayer reflecting mirrors has a structure that generates a longitudinal multimode, and the first active layer is arranged at a position shifted from a standing wave loop of the first longitudinal mode. According to the vertical cavity surface emitting laser capable of suppressing oscillation of the second longitudinal mode with a large gain and capable of single longitudinal mode oscillation based on the first longitudinal mode, the longitudinal mode spacing is narrowed by increasing the length of the resonator for single transverse mode oscillation at a high output, and the single longitudinal mode oscillation is possible even if longitudinal multimode oscillation occurs.
    Type: Grant
    Filed: October 24, 2011
    Date of Patent: February 12, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Toshimitsu Matsuu, Takeshi Uchida
  • Patent number: 8369366
    Abstract: To make it possible to use a type I nonlinear optical crystal or a quasi phase matching element as a third harmonic generation crystal there is provided a semiconductor laser, a solid state laser medium that outputs a fundamental wave, a second harmonic generation crystal that outputs a second harmonic wave from the fundamental wave, and a third harmonic generation crystal that outputs a third harmonic wave from the fundamental wave and the second harmonic wave. A quasi phase matching elements is utilized as the second harmonic generation crystal. It is possible to use a type I nonlinear optical crystal or a quasi phase matching element as the third harmonic generation crystal.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: February 5, 2013
    Assignee: Shimadzu Corporation
    Inventors: Koji Tojo, Naoya Ishigaki