Having Feedback Circuitry Patents (Class 372/38.01)
  • Patent number: 10536217
    Abstract: An optical transmission module includes: a bias current drive circuit to drive a bias current of a light-emitting element, on a basis of an input bias current setting value; a modulation current drive circuit to drive a modulation current of the light-emitting element, on a basis of an input modulation current setting value; a light-receiving element to measure an optical output power of the light-emitting element; a determiner to determine whether a difference between a target value of the optical output power and the optical output power measured by the light-receiving element is equal to or more than a threshold; and a controller configured to perform a correction control to the bias current drive circuit so that the bias current is reduced in accordance with the difference, when it is determined that the difference is equal to or more than the threshold by the determiner.
    Type: Grant
    Filed: May 23, 2017
    Date of Patent: January 14, 2020
    Inventor: Tetsuo Ishizaka
  • Patent number: 10535978
    Abstract: A system for controlling an optical intensity and modulation of an optical data transmitter which includes current driver circuitry configured to provide a drive current to a laser diode wherein said current comprises a fixed component and a modulated component, said modulated component having a magnitude related to an input data stream. The monitor circuitry contains a photodiode and a first transimpedance amplifier coupled to said photodiode, said monitor circuitry configured to provide an output signal related to an optical intensity of said laser diode. The system further includes replica monitor circuitry containing a replica capacitor with a replica capacitance and a second transimpedance amplifier configured to be substantially identical in construction to said first transimpedance amplifier, said second transimpedance amplifier coupled to said replica capacitor.
    Type: Grant
    Filed: January 30, 2018
    Date of Patent: January 14, 2020
    Inventors: William Redman-White, Dominique Coue, Colin Whitfield, Christian Rookes, Derek Hutchins, George Brocklehurst
  • Patent number: 10431954
    Abstract: A laser component includes a housing, a laser chip arranged in the housing, and a conversion element for radiation conversion arranged in the housing wherein the conversion element is irradiatable with laser radiation of the laser chip. A method of producing such a laser component includes providing component parts of the laser component including a laser chip, a conversion element for radiation conversion and housing parts, and assembling the component parts of the laser component such that a housing is provided within which the laser chip and the conversion element are arranged, wherein the conversion element is irradiatable with laser radiation of the laser chip.
    Type: Grant
    Filed: July 19, 2017
    Date of Patent: October 1, 2019
    Assignee: OSRAM Opto Semiconductors GmbH
    Inventors: Jan Seidenfaden, Jan Marfeld, Hubert Schmid, Soenke Tautz, Roland Enzmann
  • Patent number: 10353417
    Abstract: A ripple pre-amplification based fully integrated LDO pertains to the technical field of power management. The positive input terminal of a transconductance amplifier is connected to a reference voltage Vref, and the negative input terminal of the transconductance amplifier is connected to the feedback voltage Vfb. The output terminal of the transconductance amplifier is connected to the negative input terminal of a transimpedance amplifier and the negative input terminal of an error amplifier. The positive input terminal of the transimpedance amplifier is connected to the ground GND, and the output terminal of the transimpedance amplifier is connected to the positive input terminal of the error amplifier. The gate terminal of the power transistor MP is connected to the output terminal of the error amplifier, the source terminal of the power transistor MP is connected to an input voltage VIN, and the drain terminal of the power transistor MP is grounded.
    Type: Grant
    Filed: July 3, 2018
    Date of Patent: July 16, 2019
    Assignee: University of Electronic Science and Technology of China
    Inventors: Xin Ming, Jiahao Zhang, Wenlin Zhang, Di Gao, Xuan Zhang, Zhuo Wang, Bo Zhang
  • Patent number: 10341150
    Abstract: The method of phase modulating a carrier wave involves creating a set of signals sh(t) constituted by a carrier wave of frequency fC and of phase ?(t)=h?0(t) that is modulated in time t in such a manner that sh(t)=cos(2?fCt+h?0(t)), where h is an integer and where ?0(t)=2 arctan((t?t0)/w0). The modulation corresponds to a single phase pulse centered on a time t0 of characteristic duration w0 that is positive, and incrementing the phase of the signal sh(t) by the quantity h2?, in such a manner as to generate a single sideband frequency spectrum directly. The carrier wave may be of electromagnetic type or of acoustic type. The method applies in particular to transporting binary information by single sideband phase coding, to generating single sideband orthogonal signals, to detecting single sideband phase coded multiple-level digital signals, to transmitting single sideband phase coded binary signals in-phase and out-of-phase, and to single sideband combined amplitude-and-phase modulation.
    Type: Grant
    Filed: January 29, 2016
    Date of Patent: July 2, 2019
    Assignee: Commissariat A L'Energie Atomique Et Aux Energies Alternatives
    Inventors: Denis Christian Glattli, Séverin Preden Roulleau
  • Patent number: 10281320
    Abstract: System, including methods and apparatus, for optical detection. The system may comprise a light source to generate a beam of light, an optical element, and a detector. The optical element may include a light guide having a shaft and a tip, with the tip forming a beveled end of the light guide. The optical element may extend into the beam, such that the tip and at least a portion of the shaft are located inside the beam, and a window of the optical element is located outside the beam. Light of the beam incident on the tip may be transmitted longitudinally through the light guide and out the window, while light of the beam incident on the shaft may be transmitted transversely through the shaft and remains in the beam downstream. The detector may be configured to detect light received from the window.
    Type: Grant
    Filed: December 29, 2016
    Date of Patent: May 7, 2019
    Assignee: Bio-Rad Laboratories, Inc.
    Inventor: Denis Pristinski
  • Patent number: 10279598
    Abstract: The invention describes a laser printing system (100) for illuminating an object (70) in a working plane (80). The object (70) moves relative to a print head (50) of the laser printing system (100). The print head (50) comprises a total number of laser modules (150), each laser module (150) comprises at least one laser array (110) of lasers (115). At least two of the laser modules (150) share an electrical power supply (20). The laser printing system (100) further comprises a controller (10) being adapted such that at maximum processing speed of the print head (50) only a predefined number of laser modules (150) can be driven at nominal electrical power, wherein the predefined number of laser modules (150) is smaller than the total number of laser modules. The invention further relates to a corresponding method of laser printing.
    Type: Grant
    Filed: July 22, 2016
    Date of Patent: May 7, 2019
    Inventor: Carsten Deppe
  • Patent number: 10264653
    Abstract: An apparatus includes an illumination source configured to emit light when driven with a current greater than a threshold current and driver circuitry configured to drive the illumination source with a controllable current. The driver circuit controlled by at least a first input value. At least one illumination detector is configured to detect light emitted by the illumination source and monitor circuitry is configured to receive an output from the illumination detector and provide the first input value.
    Type: Grant
    Filed: May 31, 2017
    Date of Patent: April 16, 2019
    Inventor: John Kevin Moore
  • Patent number: 10097908
    Abstract: An optical signal module including a driver and an optical signal module. The driver includes a differential pair configured to receive and process an input signal to create a drive signal. A modulation current source provides a modulation current to the differential pair. One or more termination resistors connected to the differential pair for impedance matching. A first switch, responsive to a first control signal, maintains charge on a charge storage device. The optical signal module includes an optical signal generator arranged between a supply voltage node and a bias current node. The optical signal generator receives the drive signal and generates an optical signal representing the input signal. A second switch is between a supply voltage node the bias current node. The second switch, responsive to second control signal, selectively establishes a short between the supply voltage node the bias current node.
    Type: Grant
    Filed: December 31, 2014
    Date of Patent: October 9, 2018
    Assignee: MACOM Technology Solutions Holdings, Inc.
    Inventors: Matteo Troiani, Cristiano Bazzani, Yanxin Will Wang, Kevin McDonald, Atul Gupta
  • Patent number: 10096969
    Abstract: A method and apparatus for controlling a dose of radiation generated by a laser light source is disclosed. In one embodiment, a dose controller receives measurements of the deviation of output energy from an expected output energy, or “energy sigma,” and the standard deviation of the error in the dose received by the item being processed from the desired dose. The ratio of the energy sigma to the standard deviation of dose error is calculated, and the laser controller adjusts the controller gain based upon the calculated ratio so as to adjust the voltage determined by the controller, and consequently the output energy and thus the dose to the item. This is an improvement over the prior art, in which the controller gain is adjusted based upon sending a voltage dither to the laser and correlating it to its response in energy at only one frequency.
    Type: Grant
    Filed: September 14, 2017
    Date of Patent: October 9, 2018
    Assignee: Cymer, LLC
    Inventor: Tanuj Aggarwal
  • Patent number: 9980789
    Abstract: A dental laser treatment system includes a treatment laser beam and a pilot (e.g., aiming/marking) laser beam sharing a collinear beam path, where the beam path is guided by a guidance system through a handpiece/main chamber assembly having a beam exit. A laser beam presence detector is removably affixed to or within the handpiece/main chamber assembly. The laser beam presence detector provides feedback to a computer which can control actuation of the treatment laser beam and the pilot laser beam, and the beam guidance system. The computer performs a search for determining the center location of the beam exit based on the feedback and controls the beam guidance system to guide the beam path approximately to the center of the beam exit, thereby providing automatic alignment of the laser beam with the beam exit or an optional hollow waveguide.
    Type: Grant
    Filed: December 4, 2015
    Date of Patent: May 29, 2018
    Assignee: Convergent Dental, Inc.
    Inventors: Christopher B. Courtin, William H. Groves, Jr.
  • Patent number: 9722708
    Abstract: An optical signal generation section and a transmitter control section are provided. The optical signal generation section includes a light source, a temperature adjuster that adjusts a temperature of the light source, and a light amplifier that amplifies light generated by the light source and generates burst signals. The transmitter control section includes a temperature change suppresser that sends a temperature suppression signal to the temperature adjuster, the temperature suppression signal reporting a temperature suppression amount that is to suppress a temperature change of the light source caused by burst signal generation at the light amplifier. The temperature adjuster receives the temperature suppression signal at least a duration that the temperature adjuster requires for temperature adjustment before a timing at which the light amplifier is to generate a burst signal.
    Type: Grant
    Filed: January 15, 2016
    Date of Patent: August 1, 2017
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Masahiro Sarashina
  • Patent number: 9685758
    Abstract: A laser system having an automatic diagnosis function enabling a plurality of laser diodes to be diagnosed for faults in a short time. The laser system includes a judging part judging the presence of a fault or deterioration of a component of the laser system. The judging part is configured to judge the presence of a fault or deterioration of a component of the laser system based on the results of detection of a first photodetection part and second photodetection part when successively driving a plurality of laser diode module groups included in an individual laser oscillation unit so that the mutual drive times do not overlap simultaneously for at least two laser oscillation units among a plurality of laser oscillation units.
    Type: Grant
    Filed: November 8, 2016
    Date of Patent: June 20, 2017
    Assignee: Fanuc Corporation
    Inventors: Hiroshi Takigawa, Hisatada Machida
  • Patent number: 9680289
    Abstract: A laser apparatus includes laser diode module groups (LDMGs) and power supply units and provides a laser light source by collecting laser beam from the LDMGs, and comprises: a driving current supply circuit network for injecting the driving currents into the respective LDMGs, independently; a control unit which controls the driving currents independently; a first recording unit in which are recorded data representing a relationship between the driving current and optical output power, and data representing a relationship between the driving current and drive voltage; and a first calculating unit which calculates the driving currents to be allocated to the LDMGs so as to achieve maximum electrical to optical conversion efficiency, wherein the control unit allocates the driving currents to the LDMGs in accordance with the results calculated by the first calculating unit so that the LDMGs as a whole can achieve maximum electrical to optical conversion efficiency under conditions.
    Type: Grant
    Filed: September 7, 2016
    Date of Patent: June 13, 2017
    Inventors: Hiroshi Takigawa, Hisatada Machida
  • Patent number: 9472921
    Abstract: An optical transmitter driver is disclosed to drive a load with a drive signal responsive to a first and second input signal. The differential pair includes a first path having a first resistor connected to a first voltage supply and to a first transistor that receives the first input signal. A second path includes a second resistor connected to a second voltage supply and a second transistor. The first voltage supply is less than the second voltage supply. The second transistor has an input configured to receive the second input signal and the first and second input signals define a differential signal. Also part of this embodiment is a load connection node that presents the drive signal to the load. The first voltage supply is less than the second voltage supply. In one configuration cross coupled capacitor are connect between each input and the first path and second path.
    Type: Grant
    Filed: January 16, 2015
    Date of Patent: October 18, 2016
    Assignee: Macom Technology Solutions Holdings, Inc.
    Inventors: Merrick Brownlee, Atul Gupta, Vasilis Papanikolaou
  • Patent number: 9397475
    Abstract: Light with a short pulse width is emitted using a simple structure. A light source 101, a differentiation circuit 102, and a switch 103 are connected in series. When the switch 103 is switched on, inrush current flows in a capacitor 102b forming the differentiation circuit 102, and accordingly the light source 101 is supplied with electric current and thereby emits light. When the capacitor 102b is charged, electric current flows in a resistor 102a, and voltage drops at the resistor 102a. Then, the voltage applied to the light source 101 is decreased, whereby the light source 101 stops emitting light. The values of the resistor 102a and the capacitor 102b are adjusted so that the above phenomenon occurs.
    Type: Grant
    Filed: July 31, 2015
    Date of Patent: July 19, 2016
    Inventors: Yoshiaki Goto, Yoshikatsu Tokuda
  • Patent number: 9380691
    Abstract: A system for an extreme ultraviolet (EUV) light source includes an optical amplifier including a gain medium positioned on a beam path, the optical amplifier configured to receive a light beam at an input and to emit an output light beam for an EUV light source at an output; a feedback system that measures a property of the output light beam and produces a feedback signal based on the measured property; and an adaptive optic positioned in the beam path and configured to receive the feedback signal and to adjust a property of the output light beam in response to the feedback signal.
    Type: Grant
    Filed: February 28, 2014
    Date of Patent: June 28, 2016
    Assignee: ASML Netherlands B.V.
    Inventors: Yezheng Tao, Daniel J. W. Brown, Alexander Schafgans, Michael David Caudill, Daniel J. Golich, Richard L. Sandstrom, Yoshiho Amada
  • Patent number: 9256154
    Abstract: An image forming apparatus, including: a laser light source supplied with a bias current and a superimposed current to emit laser light; a splitting unit configured to split the laser light into first and second laser lights; a photoelectric conversion unit configured to output a voltage corresponding to a light intensity of the second laser light; a voltage holding unit configured to hold a voltage output from the photoelectric conversion unit with not the superimposed current but the bias current being supplied to the laser light source; a voltage conversion unit configured to remove the voltage held by the voltage holding unit from the voltage from the photoelectric conversion unit which receives the second laser light; and a current control unit configured to control, based on a voltage from the voltage conversion unit, a value of the superimposed current supplied to the laser light source based on image data.
    Type: Grant
    Filed: August 25, 2014
    Date of Patent: February 9, 2016
    Inventor: Daisuke Akagi
  • Patent number: 9215770
    Abstract: A controller may be configured to: (i) predict based on an electronic transformer secondary signal an estimated occurrence of a high-resistance state of a trailing-edge dimmer coupled to a primary winding of an electronic transformer, wherein the high-resistance state occurs when the trailing-edge dimmer begins phase-cutting an alternating current voltage signal; (ii) operate a power converter in a trailing-edge exposure mode for a first period of time immediately prior to the estimated occurrence of the high-resistance state, such that the power converter is enabled to transfer energy from the secondary winding to the load during the trailing-edge exposure mode; and (iii) operate the power converter in a power mode for a second period of time prior to and non-contiguous with the first period of time, such that the power converter is enabled to transfer energy from the secondary winding to the load during the power mode.
    Type: Grant
    Filed: September 27, 2013
    Date of Patent: December 15, 2015
    Assignee: Philips International, B.V.
    Inventors: Poornima Mazumdar, Michael A. Kost, Yanhui Xie, Sahil Singh
  • Patent number: 9178334
    Abstract: An arbitrary waveform generator modifies the input signal to a laser diode driver circuit in order to reduce the overshoot/undershoot and provide a “flat-top” signal to the laser diode driver circuit. The input signal is modified based on the original received signal and the feedback from the laser diode by measuring the actual current flowing in the laser diode after the original signal is applied to the laser diode.
    Type: Grant
    Filed: February 21, 2013
    Date of Patent: November 3, 2015
    Assignee: Lawrence Livermore National Security, LLC
    Inventor: Edward Steven Fulkerson, Jr.
  • Patent number: 9118328
    Abstract: An electronic circuit contains a flip-flop, a switch, a photodiode and a mode-locked laser. The mode-locked laser generates light pulses, which generate a photocurrent in the photodiode the switch transfers the photocurrent to one of two inputs of the flip-flop. The flip-flop outputs its status to at least one output.
    Type: Grant
    Filed: May 18, 2011
    Date of Patent: August 25, 2015
    Assignee: Rohde & Schwarz GmbH & Co. KG
    Inventor: Oliver Landolt
  • Patent number: 9065248
    Abstract: In master oscillator-power amplifier (MOPA) systems for generating laser light, a fluorine concentration in each of the master oscillator and power amplifier chambers is maintained. While sensors at the chambers can measure certain values of some variables, the sensors do not directly measure fluorine concentration. As a further complication, the values received from the sensors are known to be affected by various specified variables. To estimate the effect on the received values, an RLS algorithm and covariance matrix are used. To ensure that the RLS algorithm is responsive to recent changes in a specified variable, portions of the covariance matrix are reset to more quickly and more heavily weight the more recent values.
    Type: Grant
    Filed: November 20, 2013
    Date of Patent: June 23, 2015
    Assignee: Cymer, LLC
    Inventor: Alicia Michelle Powers Russin
  • Publication number: 20150146751
    Abstract: A light source system that generates stable optical power over time and temperature in which a feedback control circuit is operative to receive a temperature signal and a sample signal and in response thereto generate a control signal to a driver circuit to maintain a power level of the light output substantially constant over an operative temperature range defined by Tmin and Tmax.
    Type: Application
    Filed: November 18, 2014
    Publication date: May 28, 2015
    Inventor: John P. Downing
  • Publication number: 20150146750
    Abstract: A system and method that can be employed to lock and scan the output of a laser cavity (2) is described. The system and method involves the use of a signal generator for generating an error signal between an output of the laser cavity (28) and the transmission (28) of the laser through a tunable external reference cavity (3). A dual piezo-actuated mirror (6b) permits processing of the error signal (26) with separate signal processing circuits (29a, 29b) used to provide an electrical feedback signal to the two piezo electric crystals (22, 23b). When incorporated within a laser cavity the described system and methodology can be used to lock and scan the output of the laser cavity while providing the laser output with a reduced linewidth.
    Type: Application
    Filed: May 22, 2013
    Publication date: May 28, 2015
    Applicant: M Squared Lasers Limited
    Inventor: William Miller
  • Publication number: 20150131425
    Abstract: Provided is a recording apparatus including a self-excited oscillation semiconductor laser that has a double quantum well separate confinement heterostructure and includes a saturable absorber section to which a negative bias voltage is applied and a gain section into which a gain current is injected, an optical separation unit, an objective lens, a light reception element, a pulse detection unit, a reference signal generation unit, a phase comparison unit, a recording signal generation unit, and a control unit.
    Type: Application
    Filed: July 10, 2012
    Publication date: May 14, 2015
    Inventors: Goro Fujita, Tsutomu Maruyama, Masaru Kuramoto, Hideki Watanabe
  • Patent number: 9031109
    Abstract: The invention relates to solid state light source, a use of a driver circuit for driving a light emitting element (150) of a solid state light source, a method for driving a light emitting element (150) of a solid state light source and a corresponding computer program. The invention provides that for a large amount of an AC period the light emitting element (150) is directly supplied with the AC input directly forwarded by the driver circuit, wherein nevertheless it is prevented that power exceeding a desired level reaches the light emitting element (150). The invention is aimed at a realization with simplified components and/or reduced costs in comparison to known techniques.
    Type: Grant
    Filed: February 20, 2013
    Date of Patent: May 12, 2015
    Inventor: Carsten Deppe
  • Patent number: 9025629
    Abstract: A laser driver circuit having a differential circuit and an output circuit includes a control circuit receiving a regulated supply voltage that also supplies the differential circuit as an input signal. The control circuit generates a feedback voltage across a first resistor to cause a first current to flow in the first resistor having a current value equal or proportional to the modulation current value. The laser driver circuit includes an operational amplifier receiving the feedback voltage and a reference voltage indicative of a desired modulation current value and to generate the regulated supply voltage. The control circuit and the operational amplifier form a feedback control loop to adjust the regulated supply voltage to regulate the feedback voltage to be equal to the reference voltage, thereby regulating the modulation current value to the desired modulation current value.
    Type: Grant
    Filed: December 3, 2012
    Date of Patent: May 5, 2015
    Assignee: Micrel, Inc.
    Inventors: Bernd Neumann, Dieter Kuehnel, Maik Pohland
  • Publication number: 20150116435
    Abstract: A light emission apparatus includes a detection unit, a first drive unit, and a second drive unit. The detection unit detects the state of a detection element. The first drive unit controls the light amount of a light beam to be emitted by a first light emitting element based on the state of the detection element detected by the detection unit. The second drive unit controls the light amount of a light beam to be emitted by a second light emitting element based on the state of the detection element detected by the detection unit.
    Type: Application
    Filed: April 22, 2013
    Publication date: April 30, 2015
    Inventors: Tomohiro Kawamoto, Yuta Nito
  • Publication number: 20150098481
    Abstract: A method of optical signal amplification. Incident photons are received at a photodetector including a doped semiconductor biased by a power source. The photons generate a change in a reflective property, refractive index, or electrical conductivity of the doped semiconductor. For the change in reflective property or refractive index, a first optical signal is reflected off the photodetector to provide a reflected beam, or the photodetector includes a reverse biased semiconductor junction including the doped semiconductor within a laser resonator including a laser medium, wherein a second optical signal is emitted. For the change in electrical conductivity the photodetector includes a reversed biased semiconductor junction that is within an electrical circuit along with an electrically driven light emitting device, where a drive current provided to the light emitting device increases as the electrical conductivity of the photodetector decreases, and the light emitting device emits a third optical signal.
    Type: Application
    Filed: June 17, 2014
    Publication date: April 9, 2015
  • Patent number: 8995486
    Abstract: There provided is a semiconductor laser control device which including plural light sources that are configured with eight or more semiconductor laser elements, a one detecting section that detects a light power of the light sources, a light power control unit that compares a signal according to a light power detected by the detecting section with a control signal corresponding to a predetermined light power to control a current supplied to the light sources, and a voltage clamp circuit that functions as an overvoltage preventing means for the detecting section when turning on each of the light sources to perform light power control.
    Type: Grant
    Filed: September 14, 2010
    Date of Patent: March 31, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsufumi Omori, Masaaki Ishida
  • Patent number: 8989227
    Abstract: In a VCSEL driver for automatic bias control and automatic modulation control, the VCSEL driver includes: a feedback module configured to receive an output of a VCSEL to provide a bias signal through a feedback loop; an automatic bias control block configured to adjust a bias current by switching on or off a plurality of power sources, which are connected in parallel with each other; an automatic modulation control block configured to connect in parallel a plurality of bias transistors that are connected to each of the plurality of power sources, and to adjust modulation current by switching each of the plurality of bias transistors on or off; and a main driver configured to provide the VCSEL with a drive current including the bias current and the modulation current, which are adjusted by control of each of the control blocks.
    Type: Grant
    Filed: June 30, 2014
    Date of Patent: March 24, 2015
    Assignee: Electronics and Telecommunications Research Institute
    Inventor: Choong-Reol Yang
  • Patent number: 8989598
    Abstract: Methods and circuits for providing a minimum driving voltage to a current-driven load (such as a laser diode) are disclosed. The circuit and methods may be useful for efficiently providing a bias and/or driving current to the current-driven load with minimal energy loss. The circuit generally comprises (1) a driver or voltage source configured to provide the bias and/or driving current to the current-driven load, (2) a sense circuit configured to (i) sense the bias and/or driving current and (ii) convert the bias and/or driving current to a first voltage, and (3) a comparator configured to (i) receive the first voltage and first and second reference voltages and (ii) provide a feedback/error signal to the driver or voltage source, the feedback/error signal configured to maintain or adjust the bias and/or driving current at or towards a target value.
    Type: Grant
    Filed: October 11, 2012
    Date of Patent: March 24, 2015
    Assignee: Source Photonics, Inc.
    Inventor: Mohammad Azadeh
  • Patent number: 8982918
    Abstract: A light source system for delivery of light including a light source having an output arranged to emit light in an output path, the output path including an unguided section and an at least partially transmissive optical component wherein the optical component provides at least one residual reflection when the system is in use and a detector system is arranged to detect said residual reflection. The detector is in one embodiment arranged to produce at least one feedback response arranged to stabilize the optical output of the light source system. Hereby a feedback may be implemented with little or no reduction of performance.
    Type: Grant
    Filed: July 30, 2010
    Date of Patent: March 17, 2015
    Assignee: NKT Photonics A/S
    Inventor: Morten Ostergaard Pedersen
  • Publication number: 20150070698
    Abstract: A quantum cascade laser (QCL) may include a QCL crystal having an emitting facet, and an active region adjacent the emitting facet, the emitting facet for providing an electromagnetic beam. The QCL may include an optical cavity comprising a mirror being external to the QCL crystal, and for redirecting the electromagnetic beam into the active region of the QCL crystal to provide optical feedback, and a driver circuit for driving the QCL crystal with a constant current. The QCL may include a controller coupled to the optical cavity and for dynamically and autonomously aligning the optical cavity based upon an error signal from the QCL crystal to maintain stable the optical feedback into the active region of the QCL crystal.
    Type: Application
    Filed: September 11, 2014
    Publication date: March 12, 2015
    Inventors: Andrey V. MURAVIEV, Douglas MAUKONEN, Christopher J. FREDRICKSEN, Robert E. PEALE
  • Patent number: 8971364
    Abstract: A diode-laser is driven by a modulated voltage through a voltage-to-current converter. The modulated voltage has a fixed level determined by an applied fixed bias voltage and a variable level determined by a modulation voltage signal varying between minimum and maximum values. The fixed voltage level corresponds to a threshold level above which the diode-laser would provide laser-output. The modulation voltage signal is monitored and compared with a predetermined set value. If the monitored voltage signal falls below the set value, the modulated voltage is disconnected from the voltage-to-current converter and the output of the diode-laser falls to zero.
    Type: Grant
    Filed: January 19, 2011
    Date of Patent: March 3, 2015
    Assignee: Coherent, Inc.
    Inventors: Gilbert A. Hoffman, Richard J. Farmer
  • Patent number: 8958445
    Abstract: A DC-coupled laser drive circuit (1) includes (i) a voltage drop section (14) provided between a power source and a pre-driver (12) and (ii) a voltage drop amount controlling section (16) for controlling, according to an output of the pre-driver (12), an amount of a voltage drop in the voltage drop section (14).
    Type: Grant
    Filed: April 2, 2013
    Date of Patent: February 17, 2015
    Assignee: Fujikura Ltd.
    Inventor: Tatsuo Kubo
  • Publication number: 20150036707
    Abstract: An arbitrary waveform generator modifies the input signal to a laser diode driver circuit in order to reduce the overshoot/undershoot and provide a “flat-top” signal to the laser diode driver circuit. The input signal is modified based on the original received signal and the feedback from the laser diode by measuring the actual current flowing in the laser diode after the original signal is applied to the laser diode.
    Type: Application
    Filed: February 21, 2013
    Publication date: February 5, 2015
    Inventor: Edward Steven Fulkerson, JR.
  • Patent number: 8948222
    Abstract: A light source including a laser diode, and a method of operating a light source including a laser diode are disclosed. A driving current of the laser diode is dithered to cause a near-field light intensity distribution at an end facet to be perturbed, thereby reducing a time-averaged local intensity of the laser light at the end facet of the laser diode. The reduced time-averaged intensity reduces a possibility of a damage of the end facet.
    Type: Grant
    Filed: September 30, 2013
    Date of Patent: February 3, 2015
    Assignee: JDS Uniphase Corporation
    Inventors: David Venables, Erik Paul Zucker, Victor Rossin, Justin L. Franke, Boris Kharlamov
  • Patent number: 8934511
    Abstract: A method and device for providing a laser interlock having a first optical source, a first beam splitter, a second optical source, a detector, an interlock control system, and a means for producing dangerous optical energy. The first beam splitter is optically connected to the first optical source, the first detector and the second optical source. The detector is connected to the interlock control system. The interlock control system is connected to the means for producing dangerous optical energy and configured to terminate its optical energy production upon the detection of optical energy at the detector from the second optical source below a predetermined detector threshold. The second optical source produces an optical energy in response to optical energy from the first optical source. The optical energy from the second optical source has a different wavelength, polarization, modulation or combination thereof from the optical energy of the first optical source.
    Type: Grant
    Filed: September 11, 2013
    Date of Patent: January 13, 2015
    Assignee: U.S. Department of Energy
    Inventors: Steven D. Woodruff, Dustin L. Mcintyre
  • Patent number: 8923353
    Abstract: Systems and methods are provided for generating an accurate, stable measurement for a laser bias current. The average current and the extinction ratio are controlled using a dual control loop. The transfer function between the laser and a monitor photo diode (MPD) is characterized. A laser driver control module predicts the average power that will be measured using the MPD relative to the data being transmitted, and this information is used to control a laser driver.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: December 30, 2014
    Assignee: Broadcom Corporation
    Inventors: Amiad Dvir, Asaf Koren
  • Patent number: 8923351
    Abstract: In the field of the production of very high frequencies, for example from 1 gigahertz to several terahertz, by beating the frequencies of two laser beams together, a device includes a resonant optical cavity having very stable dimensions receiving the beams, with for each beam, an interrogation device of the resonant cavity supplying an electrical signal representing the difference in frequency between the light frequency of the beam and a resonance frequency of the resonant cavity. The frequency of each beam is servo controlled to minimize the frequency difference observed. The laser beams are produced by a dual-frequency laser producing two beams of different frequencies and orthogonal polarizations. A polarization separator is used for separate servo control of the beams according to polarization, and a polarizer is placed behind a main output of the resonant cavity producing an electromagnetic beam mixing the two polarizations and amplitude-modulated at the beat frequency.
    Type: Grant
    Filed: May 9, 2011
    Date of Patent: December 30, 2014
    Assignee: Centre National de la Recherche Scientifique
    Inventors: François Bondu, Marc Brunel, Mehdi Alouini, Marc Vallet, Goulc'hen Loas, Marco Romanelli
  • Publication number: 20140376582
    Abstract: An optical transmitter is disclosed. In accordance with some embodiments of the present disclosure, an optical transmitter may comprise a vertical-cavity surface-emitting laser (VCSEL) and a VCSEL driver. The VCSEL driver may comprise an input stage configured to receive a voltage signal and a low-impedance output stage comprising an input coupled to the input stage and a low-impedance output coupled to the VCSEL and configured to provide a modulated output current to the VCSEL.
    Type: Application
    Filed: June 20, 2013
    Publication date: December 25, 2014
    Inventors: Tony Shuo-Chun Kao, Nikola Nedovic
  • Patent number: 8908730
    Abstract: A laser driver apparatus, system, and method include a single laser driver. One or more threshold levels and one or more undershoot levels can be digitally combined into a single output with respect to the single laser driver to reduce the output capacitance of the single laser driver and minimize circuit power, resulting in a faster and higher fidelity signal thereof. A decoder (e.g., thermometer decoding) can also be provided, wherein the threshold level(s) and the undershoot level(s) are thermometer decoded via the decoder.
    Type: Grant
    Filed: August 1, 2012
    Date of Patent: December 9, 2014
    Assignee: LSI Corporation
    Inventors: Cameron C. Rabe, Jason P. Brenden
  • Patent number: 8885678
    Abstract: Embodiments of the present invention use an external cavity laser source with dual input terminals, such as bias current for a gain section, and a voltage signal for a modulator section. An aspect of the present invention provides an ultra-low frequency noise external cavity frequency modulated (FM) semiconductor laser source frequency stabilized by a dual electronic feedback circuitry applied to semiconductor gain section and a modulation section. A further aspect of the present invention provides an optical frequency discriminator based on homodyne phase demodulation using an unbalanced Michelson interferometer with fiber optics delay and a symmetrical 3×3 optical coupler.
    Type: Grant
    Filed: May 24, 2013
    Date of Patent: November 11, 2014
    Assignee: Redfern Integrated Optics, Inc.
    Inventor: Vladimir Kupershmidt
  • Publication number: 20140321490
    Abstract: A laser drive device capable of easily reducing influence of bias light emission and thereby preventing variation in threshold current. A light amount of a laser beam emitted from a laser diode is detected by a photodiode. A drive current supplied to the laser diode is controlled according to the detected light amount to thereby control the amount of light emitted from the laser diode to a plurality of set light amounts. A threshold current is calculated according to the detected light amount and the drive current. The light amounts are changed and selected, and threshold currents calculated with respect to respective set light amounts are compared. A light amount corresponding to a difference in threshold current not less than a predetermined value is set as a set light amount for use in light amount control of the laser diode.
    Type: Application
    Filed: April 22, 2014
    Publication date: October 30, 2014
    Inventor: Daisuke Akagi
  • Patent number: 8861559
    Abstract: A method or algorithm to control a driving current supplied to a semiconductor laser diode (LD) is disclosed. the method first prepares the look-up-table (LUT) that stores a set of parameters, ? and ?, for evaluating the modulation current Im by the equation of Im=?×Ib+?, where Ib is determined by the auto-power-control (APC) loop. In a practical operation of the LD, the APC loop determines Ib, while, Im is calculated according to the equation above by reading above two parameters corresponding to the current temperature of the LD from the LUT.
    Type: Grant
    Filed: March 29, 2012
    Date of Patent: October 14, 2014
    Assignee: Sumitomo Electric Device Innovations, Inc.
    Inventors: Fengliang Tang, Kentarou Kitagawa
  • Publication number: 20140301173
    Abstract: Apparatus and systems create differential drive signals suitable for HAMR data recording. A laser diode differential driver provides heating current pulses at a time ?1. The pulses energize a laser diode to pre-heat the magnetic medium to be written. Some embodiments duplicate portions of the laser diode circuit architecture to create a magnetic write head differential driver. The write head driver provides write current pulses to a magnetic write head in one direction with ?1 timing and in the opposite direction with ?2 timing. Both drivers utilize sets of reference voltages capable of being switched to one terminal or the other of the element to be driven. In the laser diode case, the common mode is split between the anode and cathode sections of the driver. A feedback element is added between the cathode and anode sections to provide current accuracy independent of the electrical characteristics of the selected laser diode.
    Type: Application
    Filed: April 3, 2013
    Publication date: October 9, 2014
    Inventor: Jeremy Robert Kuehlwein
  • Patent number: 8837539
    Abstract: An optical power stabilizing device is adapted to stabilize optical power of a light emitting device having a forward voltage, and includes a current generating circuit that generates a pulse-wave driving current to drive light emission of the light emitting device, an optical-type feedback circuit that outputs a first feedback voltage according to detected optical power of the light emitting device, an electrical-type feedback circuit that outputs a second feedback voltage according to the forward voltage, and a pulse wave generating circuit that generates a pulse-wave signal to control the current generating circuit according to one of the first feedback voltage and the second feedback voltage.
    Type: Grant
    Filed: November 22, 2013
    Date of Patent: September 16, 2014
    Assignee: National Chi Nan University
    Inventors: Tai-Ping Sun, Hsiu-Li Shieh, Kun-Shuan Huang, Ming-Chiao Shieh
  • Patent number: 8831056
    Abstract: Techniques and devices based on optical resonators made of nonlinear optical materials and nonlinear wave mixing to generate optical combs that are stabilized relative to an atomic reference.
    Type: Grant
    Filed: July 2, 2012
    Date of Patent: September 9, 2014
    Assignee: OEwaves, Inc.
    Inventors: Anatoliy A. Savchenkov, Lute Maleki, Andrey B. Matsko, David Seidel
  • Publication number: 20140247847
    Abstract: A laser system comprising a laser configured to generate a laser beam, a power supply arranged to provide a drive power to the laser, a photodetector arranged to detect the power of the laser beam and provide a detection signal from the power of the laser beam and a feedback loop arranged to form a feedback signal by subtracting a target signal from the detection signal wherein the feedback signal has a high bandwidth, amplify the feedback signal and adjust the drive power according to the amplified feedback signal, thereby reducing noise in the laser beam.
    Type: Application
    Filed: December 16, 2013
    Publication date: September 4, 2014
    Inventor: Alan Cox