Optical Output Stabilization Patents (Class 372/29.02)
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Patent number: 8242709Abstract: An optical transmitter includes a light-emitting device and an optical modulator that modulates light output from the light-emitting device by using an input signal. The optical transmitter includes a drive current switching controller that performs an ON/OFF switching control of a drive current of the light-emitting device, by using an ON/OFF signal as an input that controls ON/OFF of an optical output of the light-emitting device, in response to a switching of the ON/OFF signal. The optical transmitter also includes a drive current adjusting and generating unit that detects an ambient temperature, and generates a drive current that is adjusted according to the ambient temperature detected thereby. The drive current switching controller includes a differential circuit that is supplied a drive current that is generated by the drive current adjusting and generating unit and controls the drive current that is output to the light-emitting device, according to the ON/OFF signal.Type: GrantFiled: July 13, 2007Date of Patent: August 14, 2012Assignee: Mitsubishi Electric CorporationInventors: Masamichi Nogami, Masaki Noda, Naoki Suzuki
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Patent number: 8238390Abstract: Methods stabilize the output of a pulsed laser system using pulse shaping capabilities. In some embodiments, transient effects following a transition between a QCW regime and a pulse shaping regime are mitigated by ensuring that the average QCW optical power substantially corresponds to the average pulsed optical power outputted in a steady-state operation of the pulsed laser system in the pulse shaping regime. The QCW signal or the pulse shaping signal may be adapted for this purpose. In other embodiments, transient effects associated with non-process pulses emitted between series of consecutive process pulses are mitigated through the proper use of sequential pulse shaping.Type: GrantFiled: May 18, 2010Date of Patent: August 7, 2012Assignee: Institut National d'OptiqueInventors: Pascal Deladurantaye, Louis Desbiens, Yves Taillon, Dany Lemieux, Brian W. Baird
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Patent number: 8238389Abstract: Apparatus and methods of controlling a frequency-converted diode laser system are disclosed. The diode laser systems can include embodiments of thermally coupled elements facilitating temperature stabilization. Aspects of some methods include monitoring the output of a stabilized diode laser system to reduce noise of the output laser beam. Other aspects of some methods include adjusting the temperature of a frequency converter based on noise in the output beam, and/or the current provided to drive the diode laser. Systems incorporating such control aspects, and others, are also disclosed.Type: GrantFiled: February 25, 2011Date of Patent: August 7, 2012Assignee: CVI Laser, LLCInventors: David E. Hargis, Neil E. Vadnais, John O'Shaughnessy, Eric B. Takeuchi, Scott Paterson
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Patent number: 8228961Abstract: A feedback control module for stabilizing a carrier-envelope phase of an output of a laser oscillator system comprises a first photodetector, a second photodetector, a phase stabilizer, an optical modulator, and a thermal control element. The first photodetector may generate a first feedback signal corresponding to a first portion of a laser beam from an oscillator. The second photodetector may generate a second feedback signal corresponding to a second portion of the laser beam filtered by a low-pass filter. The phase stabilizer may divide the frequency of the first feedback signal by a factor and generate an error signal corresponding to the difference between the frequency-divided first feedback signal and the second feedback signal. The optical modulator may modulate the laser beam within the oscillator corresponding to the error signal. The thermal control unit may change the temperature of the oscillator corresponding to a signal operable to control the optical modulator.Type: GrantFiled: May 27, 2010Date of Patent: July 24, 2012Assignee: Kansas State University Research FoundationInventors: Zenghu Chang, Chenxia Yun, Shouyuan Chen, He Wang, Michael Chini
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Patent number: 8208512Abstract: A surface emitting semiconductor body with a vertical emission direction is specified, which is provided for operation with a resonator and comprises a semiconductor layer sequence with an active region, wherein the semiconductor body is embodied in wavelength-stabilizing fashion in such a way that a peak wavelength of the radiation generated in the active region, in a predetermined operating range of the semiconductor body, is stabilized with respect to changes in the output power of the radiation generated in the active region.Type: GrantFiled: June 28, 2007Date of Patent: June 26, 2012Assignee: OSRAM Opto Semiconductors GmbHInventors: Peter Brick, Wolfgang Diehl, Stephan Lutgen
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Patent number: 8208507Abstract: A closed loop system for controlling laser temperature without the need for additional sensors or other hardware. Embodiments utilize an existing automatic power feedback loop and existing sensors to determine the temperature of a TOSA based on changes in laser bias current, thus avoiding the need for the additional hardware. The automatic power feedback loop will modify the laser bias current as the temperature of the TOSA changes. That is, as the temperature increases, the amount of laser bias current is increased and as the temperature decreases, the amount of laser bias current is decreased. Thus, the laser bias current may be used as feedback for the laser temperature control. Accordingly, when the transceiver module drops below a predetermined temperature, a laser heater current may be controlled to thereby maintain the same laser bias current as at the preset temperature.Type: GrantFiled: December 18, 2008Date of Patent: June 26, 2012Assignee: Finisar CorporationInventors: Victor Jacob Lerner, Charles Steven Joiner, YongShan Zhang
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Patent number: 8204091Abstract: Particular embodiments of the present invention relate generally to semiconductor lasers and laser projections systems and, more particularly, to schemes for controlling semiconductor lasers. According to one embodiment of the present invention, a laser having a gain section, a phase section and a wavelength selective section is configured for optical emission of encoded data. The optical emission is shifted across a plurality of laser cavity modes by applying a quasi-periodic phase shifting signal I/V? to the phase section of the semiconductor laser. The amplitude of the quasi-periodic signal transitions periodically between a maximum drive level and a minimum drive level at a frequency that varies randomly over time.Type: GrantFiled: July 3, 2008Date of Patent: June 19, 2012Assignee: Corning IncorporatedInventors: Martin Hai Hu, Dragan Pikula, Daniel Ohen Ricketts
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Publication number: 20120147912Abstract: The present invention relates to a laser device comprising at least one large area VCSEL (101) and at least one optical feedback element (201, 301) providing an angular-selective feedback for laser radiation emitted from the laser. The angular-selective feedback is higher for at least one portion of laser radiation emitted at angles ?>0 to the optical axis (601) of the laser than for laser radiation emitted on said optical axis (601). The invention also refers to a method of stabilizing a laser emission of a large area VCSEL in a desired angular distribution (501, 502). With the proposed device and method, the intensity distribution of a large area VCSEL can be stabilized in a desired shape, for example a ring shape.Type: ApplicationFiled: August 16, 2010Publication date: June 14, 2012Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.Inventors: Holger Moench, Stephan Gronenborn
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Patent number: 8189257Abstract: A laser structure is provided that includes a pulsed source producing a pulsed signal having a low spontaneous noise component to its spectral output and a pulse-shape that is optimally flat. Also, the laser structure includes one or more optical fiber structures receiving the pulsed signal and performing Raman amplification. The pulsed signal is used to excite in the one or more optical fiber structures possessing normal chromatic dispersion, which acts as a nonlinear system for efficient mid-infrared spectral generation.Type: GrantFiled: May 1, 2009Date of Patent: May 29, 2012Assignee: Massachusetts Institute of TechnologyInventors: Peter T. Rakich, Marin Soljacic, Yoel Fink
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Patent number: 8184262Abstract: A system for equalizing pulse to pulse energy of a light beam includes a group of optical devices including an optical device configured to exhibit third order nonlinear properties. Transmission properties of an unequalized light beam passing through the group of optical devices change such that an output intensity of a resulting light beam output from the optical devices is equalized. One example configuration includes a beam splitter, a nonlinear interference filter, a mirror and a beam combiner. A first portion of the light beam that is reflected from the nonlinear interference filter is combined with the light beam such that a resulting combined light beam has equalized output intensity. Another example includes at least first and second prisms having third order nonlinear properties and configured as a beam steering system. A lithography system and a method of equalizing pulse to pulse energy in a light beam are also presented.Type: GrantFiled: October 14, 2008Date of Patent: May 22, 2012Assignee: ASML Holding N.V.Inventor: Muhammad Arif
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Publication number: 20120120973Abstract: An amusement attraction may have a laser input device where a user may wave several fingers or make repeated motions to break a laser beam in a predefined pattern. The pattern may be recognized by a controller to perform a specific function. In one embodiment, a maintenance technician may use the input device to turn on or off certain lasers in a laser maze attraction. In another embodiment, a game player may use the input device to configure the game, change conditions of the game, or perform some other function.Type: ApplicationFiled: November 12, 2011Publication date: May 17, 2012Applicant: Z-Image, LLCInventors: Theodore Bruce Ziemkowski, John Bonvallet, Conrad Proft
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Patent number: 8175127Abstract: The present invention generally relates to the operation of optical network equipment such as optical amplifiers. In one aspect, a method of operating an optical amplifier is provided such that output of the optical amplifier avoids the effects of operating an optical gain medium in a non-linear (kink) region of an L-I curve. The method generally includes operating an optical gain medium in a fully off state or fully on state above the kink region with a PWM signal. In another aspect, the effects of the kink region may be compensated for by utilizing a lookup table. A sample of the optical power of an amplified optical signal may be used to select an entry in the lookup table that compensates for non-linearities in the kink region. In yet a further aspect, a lookup table may be used to control a pulse modulator to compensate for non-linearites in the kink region of the L-I curve.Type: GrantFiled: December 16, 2010Date of Patent: May 8, 2012Assignee: Oclaro (North America), Inc.Inventors: Aravanan Gurusami, Douglas Llewellyn Butler, Timothy K. Zahnley, Scott R. Dahl, Peter G. Wigley
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Publication number: 20120092675Abstract: A method for detecting motion direction of an object (4) comprises the steps of: laser output light (L1) is generated, using a semiconductor laser (2) having a thermal response frequency (fr); the laser is driven with rectangularly modulated DC current (I) having a modulation frequency higher than said thermal response frequency (fr) and preferably higher than twice said thermal response frequency (fr), such as to triangularly modulate the wavelength of the laser output light; the laser output light is directed to the object; a portion of reflected light (L3) is allowed to interfere with light (L0) within the laser; a portion of the laser light is used as measuring beam (5); the frequency spectrum of the measuring beam (5) is analyzed in conjunction with the modulated laser current in order to determine the direction of movement of the object (4).Type: ApplicationFiled: March 24, 2010Publication date: April 19, 2012Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.Inventors: Marcel Schemmann, Cristian Presura, Carsten Heinks, Atanas Pentchev
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Patent number: 8160114Abstract: A single-mode, etched facet distributed Bragg reflector laser includes an AlGaInAs/InP laser cavity, a front mirror stack with multiple Fabry-Perot elements, a rear DBR reflector, and a rear detector. The front mirror stack elements and the rear reflector elements include input and output etched facets, and the laser cavity is an etched ridge cavity, all formed from an epitaxial wafer by a two-step lithography and CAIBE process.Type: GrantFiled: October 20, 2010Date of Patent: April 17, 2012Assignee: BinOptics CorporationInventors: Alex A. Behfar, Kiyofumi Muro, Cristian B. Stagarescu, Alfred T. Schremer
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Patent number: 8155159Abstract: A method is provided to calibrate a monitor photodiode that measures the optical output power generated by an optoelectronic transceiver module that includes a burst mode laser diode. The method includes disabling the power control loop that controls an average optical output power generated by the laser diode during a laser burst. A series of logic zero signals is applied to a data input of the transceiver module and the logic zero level of the optical signal generated by the burst mode laser diode while applying the series of logic zero signals is measured. The logic zero bias level applied to the laser diode is adjusted until the measured logic zero level of the optical signal reaches a first desired value. While maintaining the optical signal at the first desired value, a first value of a current generated by the monitor photodiode in response to optical energy received from a back facet of the laser diode is stored.Type: GrantFiled: June 13, 2008Date of Patent: April 10, 2012Assignee: General Instruments CorporationInventors: David Bowler, Jim Aufiero, Frank Calabresi, Christopher Pekalsky, Jason G. Luk
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Publication number: 20120081694Abstract: The invention relates to scanning pulsed laser systems for optical imaging. Coherent dual scanning laser systems (CDSL) are disclosed and some applications thereof. Various alternatives for implementation are illustrated, including highly integrated configurations. In at least one embodiment a coherent dual scanning laser system (CDSL) includes two passively modelocked fiber oscillators. The oscillators are configured to operate at slightly different repetition rates, such that a difference ?fr in repetition rates is small compared to the values fr1 and fr2 of the repetition rates of the oscillators. The CDSL system also includes a non-linear frequency conversion section optically connected to each oscillator. The section includes a non-linear optical element generating a frequency converted spectral output having a spectral bandwidth and a frequency comb comprising harmonics of the oscillator repetition rates.Type: ApplicationFiled: December 12, 2011Publication date: April 5, 2012Applicant: IMRA AMERICA, INC.Inventors: Martin E. FERMANN, Ingmar HARTL
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Publication number: 20120076161Abstract: Adjustable chirp is achieved in injection-locked, 10-Gb/s directly modulated, multimode 1.55-?m VCSELs for the first time, leading to 90× increase in standard single-mode fiber transmission distance to 90 km.Type: ApplicationFiled: September 15, 2011Publication date: March 29, 2012Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Connie Chang-Hasnain, Devang Parekh, Xiaoxue Zhao, Peng Guo, Weijian Yang
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Publication number: 20120044962Abstract: A laser oscillator control device includes a controller having a transmitter section and a receiver section; a laser oscillator having a transmitter section and a receiver section and communicating with the controller via a communication line; wherein the laser oscillator control device outputs a control signal from the controller to the laser oscillator, based on a status signal indicating operational state of the laser oscillator sent from the laser oscillator to the controller. The controller has an alternating signal transmitter circuit that generates an alternating signal that changes at a predetermined period, and sends this alternating signal to the laser oscillator, and the laser oscillator has a return signal transmitter circuit which generates a return signal that changes periodically in correspondence to the alternating signal from the controller, and sends this return signal to the controller.Type: ApplicationFiled: August 12, 2011Publication date: February 23, 2012Applicant: FANUC CorporationInventors: Eiji KOBAYASHI, Takeshi Watanabe
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Patent number: 8101929Abstract: Methods and systems for Airy waves and Airy wavepackets or Airy beam generation from an input beam or pulse. Airy wavefronts and Airy wavepackets can be generated using Airy beam generation through Fourier synthesis using phase masks or filters in the spatial domain; Airy beam generation using amplitude and phase filters in the spatial domain; and Airy pulse generation through Fourier synthesis using phase and/or amplitude filters in the temporal frequency domain. The Airy waves are highly asymmetric and as a result their energy is more tightly confined in one quadrant thus increasing the energy density in the main lobes. These wavepackets can be one, two, and three-dimensional waves. In addition they tend to self-heal themselves which is important in adverse environments.Type: GrantFiled: April 22, 2009Date of Patent: January 24, 2012Assignee: University of Central Florida Research Foundation, Inc.Inventors: Demetrios N. Christodoulides, Aristide Dogariu, Georgios Siviloglou
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Publication number: 20120014400Abstract: It is an object of the invention to simplify the power stabilization of laser diodes. For this purpose, a laser device comprising a die and thereon a first laser diode and a second laser diode is provided. The second laser diode has a structure or element that avoids lasing if a supply voltage is applied that is sufficient for the first semiconductor laser cavity to emit laser light.Type: ApplicationFiled: February 23, 2010Publication date: January 19, 2012Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.Inventor: Philipp Henning Gerlach
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Patent number: 8098698Abstract: According to aspects of an embodiment of the disclosed subject matter, a line narrowed high average power high pulse repetition laser micro-photolithography light source bandwidth control method and apparatus are disclosed which may comprise a bandwidth metrology module measuring the bandwidth of a laser output light pulse beam pulse produced by the light source and providing a bandwidth measurement; a bandwidth error signal generator receiving the bandwidth measurement and a bandwidth setpoint and providing a bandwidth error signal; an active bandwidth controller providing a fine bandwidth correction actuator signal and a coarse bandwidth correction actuator signal responsive to the bandwidth error. The fine bandwidth correction actuator and the coarse bandwidth correction actuator each may induce a respective modification of the light source behavior that reduces bandwidth error. The coarse and fine bandwidth correction actuators each may comprise a plurality of bandwidth correction actuators.Type: GrantFiled: November 1, 2010Date of Patent: January 17, 2012Assignee: Cymer, Inc.Inventors: Wayne J. Dunstan, Robert N. Jacques
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Patent number: 8085824Abstract: One example disclosed herein relates to a method of at least partially optimizing one or more output performance parameters of a laser die. The method includes an act of identifying one or more output performance parameters to be at least partially optimized, an act of identifying one or more design parameters associated with the one or more output performance parameters, an act of determining a subset of the one or more design parameters that should be varied so as to at least partially effect the one or more output performance parameters, an act of varying the subset of design parameters to produce one or more intermediate results, and an act of using the intermediate results to determine values for the one or more design parameters such that the one or more performance parameters are at least partially optimized.Type: GrantFiled: May 29, 2008Date of Patent: December 27, 2011Assignee: Finisar CorporationInventors: Sumesh Mani K. Thiyagarajan, Ashish K. Verma
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Publication number: 20110255562Abstract: A plane waveguide type laser according to the present invention includes: a plate-shaped laser medium (5); a semiconductor laser (1) which causes excitation light to enter an end surface (5a) of the laser medium (5); first and second claddings (4a and 4b) which are bonded to lower and upper surfaces of the laser medium (5), respectively, to form a waveguide in a vertical direction; a comb heat sink (2) bonded to a lower surface of the first cladding (4a); and thermal lens producing means (20) bonded to an upper surface of the second cladding (4b). In this structure, laser oscillation in the vertical direction is performed in a waveguide mode of the laser medium (5), and the thermal lens producing means (20) forms a periodic lens effect in the laser medium (5) to perform laser oscillation in a lateral direction in a plurality of resonant modes.Type: ApplicationFiled: February 5, 2009Publication date: October 20, 2011Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Shuhei Yamamoto, Yosuke Akino, Takayuki Yanagisawa, Yoshihito Hirano
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Patent number: 8014428Abstract: The present disclosure provides in a first aspect a mode-locked laser for generating laser pulses. The mode-locked laser comprises an optical coupler and a first optical path capable of carrying optical signals from and to the optical coupler. The first optical path includes an optical amplifier that is arranged so that saturation of optical amplification causes amplitude modulation of the light. The optical amplifier has a saturation time that is shorter than a pulse transition period of the mode-locked laser and is arranged for recovery of amplifying properties after the saturation within a period of time that is shorter than the pulse transition period of the mode-locked laser. The laser further comprises a second optical path capable of carrying optical signals from and to the optical coupler. The second optical path includes an optical isolator.Type: GrantFiled: May 30, 2008Date of Patent: September 6, 2011Assignee: University of SydneyInventors: Simon Fleming, Seong-Sik Min, Yucheng Zhao
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Patent number: 8000373Abstract: A dual-cavity single longitudinal mode (SLM) laser oscillator generates a pulsed laser signal having a long pulsewidth, long coherence length, and good shot-to-shot energy stability. The laser oscillator has a first cavity between an output coupler and a rear mirror and a second cavity between the output coupler and an intra-cavity mirror disposed between the output coupler and rear mirror. High-loss cavity optics and a passive Q-switch achieve a very high number of round trips that reduce the number of cavity modes down to two or three. The dual cavity design further discriminates between the remaining modes and allows SLM operation. The laser oscillator and an amplifier can be used as a pump laser for a laser system that generates red, green, and blue pulses for holographic recording. A wavelength conversion stage uses optical parametric amplifier(s), doubling crystals, and sum-frequency mixers to produce RGB light from the pump pulses.Type: GrantFiled: March 31, 2008Date of Patent: August 16, 2011Assignee: ITT Manufacturing Enterprises, Inc.Inventor: Dale A. Richter
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Publication number: 20110188523Abstract: Apparatus and methods of controlling a frequency-converted diode laser system are disclosed. The diode laser systems can include embodiments of thermally coupled elements facilitating temperature stabilization. Aspects of some methods include monitoring the output of a stabilized diode laser system to reduce noise of the output laser beam. Other aspects of some methods include adjusting the temperature of a frequency converter based on noise in the output beam, and/or the current provided to drive the diode laser. Systems incorporating such control aspects, and others, are also disclosed.Type: ApplicationFiled: February 25, 2011Publication date: August 4, 2011Inventors: DAVID E. HARGIS, Neil E. Vadnais, John O'Shaughnessy, Eric B. Takeuchi, Scott Paterson
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Patent number: 7991029Abstract: A cut-out portion of a ground conductor is located in a region where a header faces a flexible board from the junction of a signal pin and a signal line and faces the signal line. The size of the cut-out portion is determined so that the impedance of the signal pin is matched to the impedance of the signal line.Type: GrantFiled: August 12, 2008Date of Patent: August 2, 2011Assignee: Mitsubishi Electric CorporationInventor: Hiroshi Aruga
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Patent number: 7983314Abstract: Techniques, devices and applications of polarization stable lasers to provide laser operations against changes, variations or fluctuations in optical polarization in a laser cavity.Type: GrantFiled: January 27, 2009Date of Patent: July 19, 2011Assignee: General Photonics CorporationInventor: Xiaotian Steve Yao
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Patent number: 7978740Abstract: Systems, devices and methods of generating both a precision electrical timing signal as well as a precision optical timing signal. A novel, modified opto-electronic loop oscillator is used to drive a harmonic mode-locked laser. A novel opto-electronic loop has a larger “Q” factor by increasing the electrical loop oscillating frequency ?0 by using a beat note created by the selection of two optical longitudinal modes from the mode-locked laser. The beat note is detected and divided down to drive a modulator that mode-locks the laser. The frequency division stage also reduces the noise.Type: GrantFiled: October 5, 2007Date of Patent: July 12, 2011Assignee: University of Central Florida Research Foundation, Inc.Inventors: Peter J. Delfyett, Sangyoun Gee, Myoun-Taek Choi
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Publication number: 20110158269Abstract: A laser module includes a semiconductor laser, an output optical system provided on an optical output side of the semiconductor laser, a temperature detecting element that detects a temperature of the output optical system; and an output controller that calculates a drive current to set an optical output intensity of the laser module at a desired value on the basis of temperature information obtained by the temperature detecting element, and outputs the drive current to the semiconductor laser.Type: ApplicationFiled: February 8, 2011Publication date: June 30, 2011Applicant: EUDYNA DEVICES INC.Inventors: Haruyoshi Ono, Isao Baba
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Patent number: 7967452Abstract: A projection type display apparatus is provided that is safe even when a person looks directly into a laser beam. A laser operation control unit sets the output power of at least one laser source so that intensity A (mW/mm2) of the laser beam on at least one spatial light modulation element satisfies relationship of A<686×B2 when numerical aperture B on image side of an illumination optics system is set.Type: GrantFiled: August 24, 2006Date of Patent: June 28, 2011Assignee: Panasonic CorporationInventors: Tatsuo Itoh, Kazuhisa Yamamoto, Kenichi Kasazumi, Kiminori Mizuuchi
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Patent number: 7970028Abstract: A method of operating a laser source comprising is provided. The method reduces speckle contrast in a projected image by creating a plurality of statistically independent speckle patterns. The method comprises generating a plurality of sub-beams that define an optical mode. The method further comprises controlling the phase of selected sub-beams to continuously sequence the laser source through a plurality of orthogonal optical modes. The plurality of orthogonal modes create a corresponding number of statistically independent speckle patterns, thus reducing speckle contrast in a image projected using the laser source by time averaging.Type: GrantFiled: August 29, 2008Date of Patent: June 28, 2011Assignee: Corning IncorporatedInventors: Dmitri Vladislavovich Kuksenkov, Martin Hempstead
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Patent number: 7970026Abstract: A continuously pumped, mode-locked laser is disclosed, which includes a cavity dumper that can remove a constant fraction of the light from the cavity at every 1/f period of time, independent of the time at which the first pulse in a train is initiated. The cavity dumper includes a modulator and two output arms, denoted as a primary output arm and a secondary output arm. When a user desires a train of pulses, the pulses are directed to the primary output arm. Between trains of pulses, when no pulse is desired by the user, the pulses are directed to the secondary output arm, which terminates in an absorber or at a secondary optical system. In this manner, the energy contained in each output pulse is essentially constant, from pulse-to-pulse and from train-to-train. This may overcome the disadvantage of many lasers that have a single output arm, in which the first pulse in a train may have an energy that depends on the length of the inactive period that immediately precedes the train.Type: GrantFiled: December 30, 2009Date of Patent: June 28, 2011Assignee: Ekspla Ltd.Inventors: Mikhail Grishin, Andrejus Michailovas
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Patent number: 7970039Abstract: In a first embodiment, the invention makes use of a Neodymium doped YAG (Nd:YAG) gain medium placed in an optical resonant cavity formed by two mirrors. Power extraction is maximized for a specific laser cavity. In particular the concave curvature on the rod ends contributes a negative lensing component to modify the strength of the thermal lens. In a second embodiment the present invention uses an amplifier rod medium with curved ends to act as lensing elements to collect emission from the laser gain medium and/or oscillator described in the first embodiment of the invention. The combination of thermal lens and curved rod ends produces a lensing effect which allows light to be directly coupled from a laser. In addition, variation of the input pump power allows for control of the thermal lens formed within the amplifier rod.Type: GrantFiled: February 23, 2005Date of Patent: June 28, 2011Assignee: Powerlase Ltd.Inventors: Michael Mason, Duncan Parsons-Karavassilis, Nicolas Hay, Matthew Kelly, Andrew Comley, Burly Cumberland, Michael Poulter
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Patent number: 7961766Abstract: A method for controlling wavelengths of a multi-path laser is provided. The method includes: obtaining a difference between an actual output wavelength and a target output wavelength of each laser (S601); obtaining a corrected control amount of a temperature controller of each laser by decoupling calculation according to the difference (S602); and determining a die temperature of each laser according to the corrected control amount of the temperature controller (S603). A system for controlling wavelengths of a multi-path laser includes a multi-path laser (10), a difference module (12), a decoupling module (14), and a temperature control module (16).Type: GrantFiled: January 7, 2010Date of Patent: June 14, 2011Assignee: Huawei Technologies Co., Ltd.Inventors: Haiqing Chen, Qichao Ding, Hongpin Zhang
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Patent number: 7961772Abstract: A laser system according to the invention comprises pump generating means (x02, x03) for generating at least a first and a second, preferably focused, pump beam, and lasing means (x06, x07) for emitting radiation by being appropriately pumped. The lasing means (x06, x07) is disposed in a first resonator so as to receive the first pump beam in order to generate a first beam (x21) having a first frequency, and the lasing means (x06, x07) is disposed in a second resonator so as to receive the second pump beam in order to generate a second beam (x22) having a second frequency. At least one Q-switch (x08; x17, x18) is disposed in the first and the second resonator, so that the first beam and the second beam both pass a Q-switch (x08; x17, x18). The laser system (x01) has an output (x13) generated from said first beam (x21) and said second beam (x22), and at least a part of said output (x13) is fed back to a regulation system (x14), said regulation system (x14) controlling said pump generating means (x02, x03).Type: GrantFiled: July 10, 2007Date of Patent: June 14, 2011Assignee: AdvalightInventors: Peter Tidemand-Lichtenberg, Morten Thorhauge, Jesper Liltorp Mortensen
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Patent number: 7957438Abstract: A method for monitoring laser light launched into a core of a single mode fiber includes launching a portion of light directly into the cladding about the core. The cladding launched light is a known fraction of the core launched light and can be monitored by placing a detector about the cladding. Detected light including light that was launched into the cladding and has leaked through the cladding is used as a known fraction of light in the core and can be used to control the laser light source. This can be done with a straight section of single mode optical fiber and does not require bending the fiber. Advantageously, most of the core launched light remains in the core as guided light.Type: GrantFiled: December 16, 2008Date of Patent: June 7, 2011Assignee: JDS Uniphase CorporationInventors: David Simons, Boris Kharlamov, James Wong, Vincent Issier, Andy Miller, James Nunley
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Patent number: 7948669Abstract: Exemplary methods of maximizing a spur-free dynamic range (SFDR) or a gain of an electro-absorption modulator (EAM) are disclosed. At least one parameter in a set of design parameters for an EAM is varied. An SFDR of the EAM is determined in part by a first set of design parameters. A gain of the EAM is determined in part by a second set of design parameters. An output versus bias voltage transfer curve of the EAM is generated. An optimal SFDR bias voltage at which a maximum SFDR occurs for a given optical input power or an optimal gain bias voltage at which a maximum gain occurs for a given optical input power is programmatically determined based at least in part on the transfer curve.Type: GrantFiled: April 29, 2009Date of Patent: May 24, 2011Assignee: Lockheed Martin CorporationInventors: Thomas W. Karras, David L. Enlow, Paul Kit Lai Yu
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Publication number: 20110116520Abstract: The invention relates to a laser-based light source comprising a laser device (1) adapted for generating laser light of a predetermined laser wavelength and emitting this laser light as a laser beam; a light-conversion device (2) for converting at least part of the laser light into converted light; a laser-output sensor (7) for determining a laser-output signal proportional to the output of laser light emitted by the laser device (1); a converted-light sensor (6) for determining a converted-light signal proportional to the output of converted light emitted by the light-conversion device (7); and a controller (9) which is adapted for receiving the laser-output signal and the converted-light signal, for determining a safe-to-operate parameter, based on the laser-output signal and the converted-light signal, and for controlling the operation of the laser-based light source, based on a comparison of the safe-to-operate parameter with a at least one predefined threshold.Type: ApplicationFiled: July 7, 2008Publication date: May 19, 2011Applicant: Koninklijke Philips Electronics N.V.Inventors: Marcellinus Petrus Carolus Michael Krijn, Martin Jacobus Johan Jak
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Patent number: 7940819Abstract: A tunable laser module includes a tunable laser section including a gain medium and a wavelength filter having a periodic characteristic which brings about a discontinuous variation of an oscillation wavelength, and a monitoring section adapted to output a monitoring signal which periodically varies in response to the oscillation wavelength of the tunable laser section. The monitoring section includes a monitoring wavelength filter having a periodic characteristic which defines the monitoring signal. The relationship between the period of the wavelength filter and the period of the monitoring wavelength filter is set such that the monitoring signal varies when the oscillation wavelength varies discontinuously.Type: GrantFiled: August 4, 2009Date of Patent: May 10, 2011Assignees: Fujitsu Limited, Eudyna Devices Inc.Inventors: Kazumasa Takabayashi, Tsutomu Ishikawa, Hirokazu Tanaka
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Publication number: 20110090558Abstract: The present invention generally relates to the operation of optical network equipment such as optical amplifiers. In one aspect, a method of operating an optical amplifier is provided such that output of the optical amplifier avoids the effects of operating an optical gain medium in a non-linear (kink) region of an L-I curve. The method generally includes operating an optical gain medium in a fully off state or fully on state above the kink region with a PWM signal. In another aspect, the effects of the kink region may be compensated for by utilizing a lookup table. A sample of the optical power of an amplified optical signal may be used to select an entry in the lookup table that compensates for non-linearities in the kink region. In yet a further aspect, a lookup table may be used to control a pulse modulator to compensate for non-linearites in the kink region of the L-I curve.Type: ApplicationFiled: December 16, 2010Publication date: April 21, 2011Inventors: Aravanan Gurusami, Douglas Llewellyn Butler, Timothy K. Zahnley, Scott R. Dahl, Peter G. Wigley
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Patent number: 7929585Abstract: Systems and methods for high brightness, improved phase characteristics laser diodes.Type: GrantFiled: November 15, 2007Date of Patent: April 19, 2011Inventor: Michael M. Tilleman
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Patent number: 7929581Abstract: A testing method of a wavelength-tunable laser having a resonator including wavelength selection portions having wavelength property different from each other includes a first step of controlling the wavelength-tunable laser so as to oscillate at a given wavelength according to an initial setting value, a second step of tuning the wavelength property of the wavelength selection portions and detecting discontinuity point of gain-condition-changing of the wavelength-tunable laser, and a third step of obtaining a stable operating point of the wavelength selection portion according to a limiting point of an oscillation condition at the given wavelength, the limiting point being a point when the discontinuity point is detected.Type: GrantFiled: December 23, 2008Date of Patent: April 19, 2011Assignee: Eudyna Devices Inc.Inventors: Tsutomu Ishikawa, Toyotoshi Machida, Hirokazu Tanaka
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Patent number: 7924893Abstract: The invention provides a method and laser system for switching from a current operating point to a new operating point of the laser, the laser operating at a particular wavelength and includes a source channel and destination channel. The system switches and locks the output wavelength of a laser at ultra fast time scales (<50 ns) and compensate for degradation in the laser, and thermal transients in the device during the switching to ensure that within a certain time the laser has switched its wavelength to another wavelength within a specific accuracy and is not dependent on the previous wavelength of the laser.Type: GrantFiled: August 29, 2008Date of Patent: April 12, 2011Inventor: Thomas Farrell
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Patent number: 7920611Abstract: It is an object to provide a laser apparatus, a laser irradiating method and a manufacturing method of a semiconductor device that make laser energy more stable. To attain the object, a part of laser beam emitted from an oscillator is sampled to generate an electric signal that contains as data energy fluctuation of a laser beam. The electric signal is subjected to signal processing to calculate the frequency, amplitude, and phase of the energy fluctuation of the laser beam.Type: GrantFiled: December 18, 2007Date of Patent: April 5, 2011Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Hidekazu Miyairi, Akihisa Shimomura, Tamae Takano, Masaki Koyama, Koichiro Tanaka
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Patent number: 7907656Abstract: A harmonic frequency conversion module is disclosed including a polarization maintaining (PM) fiber optical link for providing an output stabilized from power fluctuation by the inclusion of one or more polarizers in the PM fiber optical link. Removing polarization distortions removes noise which has a significant negative effect on the output of harmonic frequency conversion elements. It has been found that the noise in frequency converted light has additional components, caused by mode interaction during conversion. In accordance with the present invention, we are able to remove the spikes in this noise, making it more stable and less dependent on external conditions. If the PM optical fiber route consists of multiple elements creating polarization distortions, a polarizer should be inserted between the most distorting element and the output of the fiber system. If many elements contribute to polarization distortions, several polarizers can be inserted into the system.Type: GrantFiled: November 26, 2007Date of Patent: March 15, 2011Assignee: JDS Uniphase CorporationInventors: Boris Kharlamov, Vincent Issier, Andy Miller
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Patent number: 7899097Abstract: A synchronized delay-coupled laser system includes at least two lasers. Each laser includes a laser fiber with a coupling means for coupling to a laser pump. The lasers are coupled to each other by way of two optical fibers. Each laser also includes a self-feedback section. The optical fibers interconnecting the lasers and the self-feedback sections are configured to provide a substantially identical delay time. The lasers may be ring lasers, may be semi-conductor or solid state, and may include components such as a fiber amplifier, a polarization controller, and a nonlinear oscillator. The system includes multiple interconnected lasers and also employ cross-coupling connections.Type: GrantFiled: December 4, 2008Date of Patent: March 1, 2011Assignee: The United States of America as represented by the Secretary of the NavyInventors: Leah B Shaw, Ira B Schwartz
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Patent number: 7899096Abstract: A method for aligning an optical package includes applying a dither waveform and an advancement waveform to a drive mechanism. The optical package includes a semiconductor laser operable to emit an output beam with a first wavelength, a wavelength conversion device operable to convert the output beam to a second wavelength, adaptive optics configured to optically couple the output beam into a waveguide portion of an input facet of the wavelength conversion device, and a drive mechanism coupled to the adaptive optics and configured to adjust a position of the output beam. The dither waveform oscillates the adaptive optics back and forth in first and second directions to oscillate the output beam on the input facet. The advancement waveform advances the adaptive optics in an adjustment direction. Rising and falling edge times of the dither waveform are greater than rising and falling edge times of the advancement waveform.Type: GrantFiled: October 30, 2009Date of Patent: March 1, 2011Assignee: Corning IncorporatedInventors: Vikram Bhatia, David Gustave Ehrenberg, Dragan Pikula
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Patent number: 7894495Abstract: A system for controlling optical-power stability of emitting laser diodes (204), the laser diodes exhibiting temperature changes at the laser diode junctions (312), the temperature changes are predicted according to the laser diodes duty cycle. The system includes, a laser diodes arranged to emit light on a target (14); a data stream analyzer (408) configured to receive incoming data stream (324) analyze the data and produce an image data occurrence factor of larger than zero values (424) representing the data in the incoming data stream (324); and an optical power stabilizer (412) configured to control current intensity (428) applied on a laser diode according to the image data occurrence factor (424).Type: GrantFiled: March 9, 2009Date of Patent: February 22, 2011Assignee: Eastman Kodak CompanyInventors: Aurel Faibis, Tamir Segev
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Patent number: 7891818Abstract: A projection system that includes a singe light modulation device and a plurality of light sources of different wavelengths. Each wavelength of light is incident on the light modulation device at a spatially distinct location and a temporally distinct time. The use of a scanning mirror allows the projection system to sequentially form, in full-color, each of the columns or rows of an image. The projection system is characterized by the reduction of color separation or the rainbow effect due to the rendering of each column or row in full color.Type: GrantFiled: December 12, 2007Date of Patent: February 22, 2011Assignee: Evans & Sutherland Computer CorporationInventors: Robert R. Christensen, Bret D. Winkler, Dennis Elkins, Allen H. Tanner