Having Feedback Circuitry Patents (Class 372/38.01)
  • Publication number: 20120275290
    Abstract: A laser diode write driver is described.
    Type: Application
    Filed: April 29, 2011
    Publication date: November 1, 2012
    Inventor: Douglas Warren Dean
  • Patent number: 8274416
    Abstract: A digital-to-analog (DA) converter includes: an analog output section that generates an output current corresponding to a value of a digital signal in response to a bias voltage and outputs an analog signal which is obtained from the output current by current-to-voltage conversion; a current source; a current control section that converts a current from the current source to a voltage signal and outputs the voltage signal as the bias voltage; and a sample and hold circuit section that samples and holds the bias voltage from the current control section and supplies the held bias voltage to the analog output section.
    Type: Grant
    Filed: April 16, 2010
    Date of Patent: September 25, 2012
    Assignee: Sony Corporation
    Inventors: Takashi Kawaguchi, Ryugi Yoshimura
  • Patent number: 8254420
    Abstract: Laser light wavelength control is provided by periodically predicting a next position of a light controlling prism using a model of the prism's motion characteristics. The prediction is then updated if a measurement of laser output wavelength is obtained. However, because the predictions are made without waiting for a measurement, they can be made more frequently than the laser firing repetition rate and the prism can be repositioned at discrete points in time which can occur more frequently than the laser firing events. This also reduces performance degradation which may be caused by being one pulse behind a laser measurement and the resultant laser control signal being applied.
    Type: Grant
    Filed: November 18, 2009
    Date of Patent: August 28, 2012
    Assignee: Cymer, Inc.
    Inventors: Daniel J. Riggs, Olav Haugan
  • Patent number: 8238395
    Abstract: A automatic power control loop comprises a photo diode used for sensing a light intensity of a laser diode to generate a feedback current, a switch selector used for selecting one among a plurality of predetermined currents according to a control signal generated by a controller, a transducer used for transferring a current different between the feedback current and the selected predetermined current into a load voltage, a comparator used for comparing the load voltage with a reference voltage to generate a comparison signal, a counter used for counting a count value according to the comparison signal and the control signal, and a laser diode driver used for generating a corresponding bias current in response to the count value to drive the laser diode. Thereby, the bias current will be adjusted within an allowable range, so that the light source of the laser diode can maintain a constant light intensity.
    Type: Grant
    Filed: July 19, 2011
    Date of Patent: August 7, 2012
    Assignee: TM Technology, Inc.
    Inventors: Chih-yang Wang, Chi-Ping Wang
  • Patent number: 8238393
    Abstract: A multi-beam laser light-intensity control circuit includes laser diodes; a light-receiving element for receiving a laser beam emitted from each laser diode and outputting a current corresponding to the light intensity of the received laser beam; and an automatic power control circuit for automatically controlling output power of each laser diode based on the current output from the light-receiving element.
    Type: Grant
    Filed: July 19, 2010
    Date of Patent: August 7, 2012
    Assignee: Ricoh Company, Ltd.
    Inventor: Mitsutaka Iwasaki
  • Patent number: 8238394
    Abstract: The present patent application provides a low power consumption pump driving circuit including a laser cooling chip, a PMOS transistor, a NMOS transistor, a LC filter circuit, a laser, and a voltage sampling circuit. The pulse width modulating signal generated by the laser cooling chip and the control terminal of the PMOS transistor are connected to the gate of the PMOS transistor. The source of the PMOS transistor is connected to a power supply. The drain of the PMOS transistor is connected to the LC filter circuit. The other terminal of the LC filter circuit is connected to the anode of the laser. The cathode of the laser is connected to the drain of the NMOS transistor. The source of the NMOS transistor is connected to the ground. One terminal of the voltage sampling circuit is connected to the laser. The other terminal of the voltage sampling circuit is connected to the laser cooling chip.
    Type: Grant
    Filed: March 1, 2010
    Date of Patent: August 7, 2012
    Assignee: O-Net Communications (Shenzhen) Limited
    Inventors: Jing Wei Wang, Ai Hua Yu
  • Patent number: 8232687
    Abstract: The present invention comprises, in various embodiments, systems and methods for shutting down a laser system in an intelligent and flexible manner. An intelligent laser interlock system includes both hardwired components, and intelligent components configured to execute computing instructions. The hardwired components and the intelligent components are configured to shutdown the laser system to one or more alternative shutdown states in response to one or more interlock signals.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: July 31, 2012
    Assignee: Raydiance, Inc.
    Inventors: Andrew D. Stadler, David Goldman, Mark Farley, Michael Mielke
  • Patent number: 8228961
    Abstract: 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: Grant
    Filed: May 27, 2010
    Date of Patent: July 24, 2012
    Assignee: Kansas State University Research Foundation
    Inventors: Zenghu Chang, Chenxia Yun, Shouyuan Chen, He Wang, Michael Chini
  • Patent number: 8223812
    Abstract: An optical scanning apparatus includes a light source configured to emit a plurality of laser beams from a plurality of light emitting parts, a beam shaping unit configured to shape the laser beams emitted from the light source, a detection unit provided outside the light source and configured to detect an amount of a laser beam that is not shaped by the beam shaping unit in the laser beams emitted from the light source in an area outside the beam shaping unit, and a light amount control unit configured to control amounts of the laser beams emitted from the light source based on a detection result detected by the detection unit. The detection unit includes a plurality of light-sensitive elements. The light amount control unit controls the light amounts of the laser beams emitted from the light source based on detection results of the light-sensitive elements.
    Type: Grant
    Filed: May 13, 2008
    Date of Patent: July 17, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventor: Shingo Kitamura
  • Patent number: 8204091
    Abstract: 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: Grant
    Filed: July 3, 2008
    Date of Patent: June 19, 2012
    Assignee: Corning Incorporated
    Inventors: Martin Hai Hu, Dragan Pikula, Daniel Ohen Ricketts
  • Publication number: 20120134378
    Abstract: A semiconductor laser driving device that drives a semiconductor laser with a driving current output from a driving current output terminal is disclosed. The semiconductor laser driving device includes a driving current monitoring terminal configured to output a driving current monitoring current having a value of 1/? of the driving current; a current-voltage conversion resistor connected to the driving current monitoring terminal and configured to convert the driving current monitoring current having the value of 1/? of the driving current into a corresponding driving current monitoring voltage; and a detector configured to generate a reference voltage and detect whether the corresponding driving current monitoring voltage has reached the reference voltage.
    Type: Application
    Filed: July 14, 2010
    Publication date: May 31, 2012
    Inventor: Tomohiko Kamatani
  • Patent number: 8189632
    Abstract: A laser emission device comprises a plurality of laser elements, a plurality of laser driving power supplies, optical elements which uniformize the laser light amount distributions of laser lights, plural light-receiving elements, a measurement unit which measures at least the relations between the operation current values of the laser elements and the output power values of the laser lights with respect to the operation current values, and the control unit operates the laser driving power supplies according to the operation current values and the output power values so as to make the light output powers of the laser elements different from each other.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: May 29, 2012
    Assignee: Panasonic Corporation
    Inventors: Tetsuro Mizushima, Akihiro Morikawa, Kazuhisa Yamamoto, Kenichi Kasazumi, Hiroyuki Furuya, Shinichi Kadowaki
  • Patent number: 8184670
    Abstract: In a pulsed laser diode driver an energy storage capacitor is continuously being charged to a supply voltage Vr. When a pulse is initiated, energy stored in the capacitor is delivered to the laser diode load. The capacitor voltage Vd at the end of a pulse is used to control Vr to ensure that Vd is maintained above a minimum voltage Vm required to ensure operation of a current control device (such as FET) just above saturation. Test pulses (such as with attenuated currents or reduced pulsewidth) may be fired to determine an initial optimum value for Vr. After a test pulse, a slightly high estimate for Vr may be used and may be iterated (incremented) down to an optimum value Vm during a firing burst. A digital processor may be used to calculate and store data to optimize the performance. Various embodiments are disclosed.
    Type: Grant
    Filed: October 7, 2010
    Date of Patent: May 22, 2012
    Assignee: Analog Modules, Inc.
    Inventors: Ian D. Crawford, John A. Harwick, Timothy M Ayres
  • Patent number: 8178826
    Abstract: A light source device including a semiconductor light emitting element and a control section for controlling the semiconductor light emitting element in accordance with an input value. The control section includes a supply section that supplies the semiconductor light emitting element with a drive current based on the input value and an estimated threshold current of the semiconductor light emitting element, and an estimation section that obtains the estimation of the threshold current using the drive current and the amount of light detected to be emitted from the semiconductor light emitting element.
    Type: Grant
    Filed: October 9, 2008
    Date of Patent: May 15, 2012
    Assignee: Seiko Epson Corporation
    Inventor: Tomio Ikegami
  • Patent number: 8175126
    Abstract: This invention relates to opto-electronic systems using semiconductor lasers driven by optical phase-locked loops that control the laser's optical phase and frequency. Feedback control provides a means for precise, wideband control of optical frequency and phase, augmented further by four wave mixing stages and digitally stitched independent optical waveforms for enhanced tunability.
    Type: Grant
    Filed: August 13, 2009
    Date of Patent: May 8, 2012
    Assignees: Telaris, Inc., California Institute of Technology
    Inventors: George Rakuljic, Naresh Satyan, Arseny Vasilyev, Ammon Yariv
  • Patent number: 8170077
    Abstract: A transistor outline (TO) package includes a housing having a window and a substrate. Circuitry is coupled to the substrate within the housing. The circuitry comprises a laser diode and memory configured to store information related to the TO package. Electrical connectors are coupled to the substrate at the opposite side to the circuitry. At least one of the electrical connectors is electrically connected to the memory. A disclosed method includes assembling a TO package, testing the TO package, storing results of the testing in memory, and making the information stored in the memory, including the results of the testing, available to a device external to the TO package. The TO package includes a laser diode and memory configured to store information related to the TO package.
    Type: Grant
    Filed: June 4, 2008
    Date of Patent: May 1, 2012
    Assignee: Finisar Corporation
    Inventor: Radek Sedlacik
  • Patent number: 8169164
    Abstract: A light output control device for laser light sources for respective RGB colors includes, for each of RGB, three sets, each including: a semiconductor laser for one of the colors; light output detection unit for detecting a light output from the semiconductor laser; light output adjustment unit for updating a light output target value; light output control unit for controlling the semiconductor laser based on the updated light output target value; and division unit for dividing the light output by an output from the light output adjustment unit to obtain a ratio of the rising of the light output, and includes rising determination unit for determining, based on results obtained by the respective division unit, a semiconductor laser with a slowest rising and outputs light output adjustment values for the respective colors. The light output adjustment unit update their respective light output target values based on the light output adjustment values.
    Type: Grant
    Filed: June 6, 2008
    Date of Patent: May 1, 2012
    Assignee: Panasonic Corporation
    Inventors: Shuji Inoue, Takahiro Kobayashi, Hiroshi Mitani, Toshiki Onishi, Yuichi Nishikoji
  • Patent number: 8170074
    Abstract: A method of estimating an injection power of seed light injected into an injection-seeded transmitter. A back face monitoring (BFM) response of the injection-seeded transmitter is determined, and data representative of the BFM response stored in a memory. During run-time, a controller of the injection-seeded transmitter, detects a temperature of the injection-seeded transmitter and an instantaneous BFM current. BFM response data is obtained from the memory based on the detected temperature, and the seed light injection power estimated based on the obtained data and the detected instantaneous BFM current.
    Type: Grant
    Filed: April 8, 2011
    Date of Patent: May 1, 2012
    Assignee: Nortel Networks Limited
    Inventors: Bin Cao, Douglas James Beckett, Tom Luk, Rong Chen
  • Patent number: 8155159
    Abstract: 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: Grant
    Filed: June 13, 2008
    Date of Patent: April 10, 2012
    Assignee: General Instruments Corporation
    Inventors: David Bowler, Jim Aufiero, Frank Calabresi, Christopher Pekalsky, Jason G. Luk
  • Publication number: 20120057611
    Abstract: 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: Application
    Filed: May 27, 2010
    Publication date: March 8, 2012
    Applicant: KANSAS STATE UNIVERSITY RESEARCH FOUNDATION
    Inventors: Zenghu Chang, Chenxia Yun, Shouyuan Chen, He Wang, Michael Chini
  • Publication number: 20120051378
    Abstract: Embodiments of the present disclosure provide systems, devices, and methods for photodetection. For example, briefly described, in one embodiment among others, a sensor comprises an array of photodetectors, wherein the reflectance of each of the photodectors is a function of the number of photons incident on the respective photodetector; and an electrical insulator positioned between one of the photodetectors and another one of the photodetectors to reduce diffusion of electrons therebetween.
    Type: Application
    Filed: December 9, 2010
    Publication date: March 1, 2012
    Inventors: Aravinda Kar, Tariq Manzur
  • Publication number: 20120051379
    Abstract: A automatic power control loop comprises a photo diode used for sensing a light intensity of a laser diode to generate a feedback current, a switch selector used for selecting one among a plurality of predetermined currents according to a control signal generated by a controller, a transducer used for transferring a current different between the feedback current and the selected predetermined current into a load voltage, a comparator used for comparing the load voltage with a reference voltage to generate a comparison signal, a counter used for counting a count value according to the comparison signal and the control signal, and a laser diode driver used for generating a corresponding bias current in response to the count value to drive the laser diode. Thereby, the bias current will be adjusted within an allowable range, so that the light source of the laser diode can maintain a constant light intensity.
    Type: Application
    Filed: July 19, 2011
    Publication date: March 1, 2012
    Inventors: Chih-yang Wang, Chi-Ping Wang
  • Patent number: 8121160
    Abstract: A driver circuit for a semiconductor laser diode (LD) is disclosed, in which the driver circuit drives the LD in the differential mode and lowers the power consumption thereof. The driver circuit includes a differential unit to provide the modulation current to the LD, a voltage converter to provide a positive power supply to the differential unit, a detector to detect the common mode voltage of the differential outputs of the unit, and a comparing unit to control the voltage converter dynamically such that the output common mode voltage is set in a preset reference level.
    Type: Grant
    Filed: March 12, 2009
    Date of Patent: February 21, 2012
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Akihiro Moto, Katsumi Uesaka
  • Publication number: 20120039349
    Abstract: An assembly (10) that generates a laser beam (12) includes a voltage source (14), a gain medium (24A), a closed loop current regulator (22), and a controller (18). The gain medium (24A) generates the laser beam (12) when medium current flows through the gain medium (24A). The current regulator (22) regulates the medium current that flows through gain medium (24A) from the voltage source (14) independent of a voltage of the voltage source (14). The controller (18) directs a command input (20) to the current regulator (22) that is used to control the current regulator (22).
    Type: Application
    Filed: August 16, 2011
    Publication date: February 16, 2012
    Inventors: Allen Priest, David Boyden
  • Patent number: 8102889
    Abstract: A method and apparatus are disclosed for controlling bandwidth in a multi-portion laser system comprising a first line narrowed oscillator laser system portion providing a line narrowed seed pulse to an amplifier laser system portion, may comprise utilizing a timing difference curve defining a relationship between a first laser system operating parameter other than bandwidth and the timing difference and also a desired point on the curve defining a desired timing difference, wherein each unique operating point on the curve corresponds to a respective bandwidth value; determining an actual offset from the timing difference at the desired point on the curve to an actual operating point on the curve; determining an error between the actual offset and a desired offset corresponding to a desired bandwidth; modifying the firing differential timing to remove the error between the actual offset and the desired offset.
    Type: Grant
    Filed: August 10, 2010
    Date of Patent: January 24, 2012
    Assignee: Cymer, Inc.
    Inventors: Robert N. Jacques, William N. Partlo, Daniel J. W. Brown
  • Patent number: 8098698
    Abstract: 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: Grant
    Filed: November 1, 2010
    Date of Patent: January 17, 2012
    Assignee: Cymer, Inc.
    Inventors: Wayne J. Dunstan, Robert N. Jacques
  • Publication number: 20120008652
    Abstract: One embodiment of the invention includes an optical system. The optical system includes an optical cavity comprising a plurality of reflectors. The optical system also includes optics configured to provide a first optical signal and a second optical signal into respective inputs of the optical cavity to be substantially concurrently resonated within the optical cavity. The first and second optical signals can have distinct wavelengths.
    Type: Application
    Filed: July 9, 2010
    Publication date: January 12, 2012
    Inventors: George Gigioli, Edward Y. Luzhansky
  • Patent number: 8094693
    Abstract: A laser control method includes the steps of: using a laser control circuit which includes a constant current circuit that maintains a constant current flowing through a semiconductor laser element, and which includes an adder and a multiplier connected to a stage preceding the constant current circuit, and using detection means for calibration for detecting an applied laser output; calculating, on the basis of a detection signal output from the detection means, a reference bias value and a reference gain value for obtaining a specified laser output with respect to a specified input to the multiplier; inputting the reference bias value and the reference gain value to the adder and the multiplier, respectively; and controlling the applied laser output from the semiconductor laser element by performing calibration.
    Type: Grant
    Filed: November 25, 2009
    Date of Patent: January 10, 2012
    Assignee: Sony Disc & Digital Solutions Inc.
    Inventors: Kunio Nakayama, Koji Ishiwata, Cheonseok Park
  • Patent number: 8080773
    Abstract: The present invention relates to a method of measuring backward light, which is constructed for checking, prior to laser processing, backward light that propagates backward through an isolator included in a laser processing apparatus. The present invention also relates to a laser processing method and the like. A laser processing apparatus has an optical head provided with a laser light source part, light guide, and isolator. The optical head has an emitting optical system, irradiation optical system, and light collecting optical system. The method of measuring backward light uses a photodetector to detect, from reference light introduced from a measurement light source into the optical head, the power of an optical component that has passed through the isolator, while changing the position of the measurement light source.
    Type: Grant
    Filed: February 25, 2009
    Date of Patent: December 20, 2011
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Shinobu Tamaoki, Motoki Kakui, Kazuo Nakamae
  • Publication number: 20110305253
    Abstract: A semiconductor laser module includes a semiconductor laser section, a light selecting section, and an optical converting section. The semiconductor laser section includes a semiconductor laser substrate, a plurality of semiconductor laser elements mounted on the semiconductor laser substrate, and a first temperature adjusting element for adjusting temperature of the semiconductor laser elements. The light selecting section includes a light selecting element substrate and a light selecting element mounted on the light selecting element substrate and optically connected to the semiconductor laser elements, which selects laser light output from at least one of the semiconductor laser elements.
    Type: Application
    Filed: June 8, 2011
    Publication date: December 15, 2011
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Go KOBAYASHI, Tatsuya KIMOTO, Toshio KIMURA, Takeshi AKUTSU, Kazutaka NARA
  • Patent number: 8073029
    Abstract: To provide a semiconductor optical device which can restrain laser characteristics from being deteriorated by excitation in a substrate mode and can reduce the number of manufacturing steps. A semiconductor optical device comprises a first DBR layer, provided on a semiconductor substrate, having first and second semiconductor layers stacked alternately, a first cladding layer, an active layer, and a second cladding layer. The semiconductor substrate has a bandgap higher than that of the active layer. The first DBR layer is transparent to light having an emission wavelength, while the first and second semiconductor layers have respective refractive indices different from each other. Since the first DBR layer is thus provided between the semiconductor substrate and first cladding layer, the guided light reaching the lower end of the first cladding layer, if any, is reflected by the first DBR layer, whereby light can be restrained from leaking to the semiconductor substrate.
    Type: Grant
    Filed: January 26, 2009
    Date of Patent: December 6, 2011
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Jun-ichi Hashimoto
  • Publication number: 20110274127
    Abstract: The object is to measure the carrier envelope offset frequency of a mode-locked laser.
    Type: Application
    Filed: January 31, 2011
    Publication date: November 10, 2011
    Applicants: National Institute of Advanced Industrial Science and Technology, ADVANTEST CORPORATION
    Inventors: Shin MASUDA, Hajime INABA
  • Patent number: 8054324
    Abstract: An optical head includes a plurality of unit regions repeatedly arrayed in one direction. Each region is constituted by a light-emitting element which is driven by a current to emit light, a control transistor which is connected in parallel with the light-emitting element, and which receives gray-scale data that specifies a high gray-scale level for the light-emitting element so as to be turned off and which receives gray-scale data that specifies a low gray-scale level for the light-emitting element so as to be turned on, and a driving transistor which is connected in series with the light-emitting element to generate a current. In each of the plurality of unit regions, a thermal resistance between the light-emitting element formed in the unit region and the control transistor formed in the unit region is smaller than a thermal resistance between the light-emitting element and a control transistor formed in a unit region adjacent to the unit region.
    Type: Grant
    Filed: January 23, 2007
    Date of Patent: November 8, 2011
    Assignee: Seiko Epson Corporation
    Inventor: Hideto Ishiguro
  • Publication number: 20110255565
    Abstract: The invention provides a laser light detection circuit that prevents a peak output occurring when the circuit switches between the operation stop mode and the operation mode so as to prevent the breakdown or malfunction of the next-connected circuit. A laser light detection circuit has a differential amplifier that amplifies and outputs a signal corresponding to the intensity of laser light, a drive transistor having a base to which the output of the differential amplifier is applied, a second constant-current source connected to the emitter of the drive transistor, an output transistor having a base connected to the emitter of the drive transistor, a bypass transistor connected between the emitter of the drive transistor and the ground, and a control circuit. The control circuit forms a bypass current route from the second constant-current source to the ground through the bypass transistor by turning on the bypass transistor when the circuit switches from the operation stop mode to the operation mode.
    Type: Application
    Filed: April 14, 2011
    Publication date: October 20, 2011
    Applicant: ON Semiconductor Trading, Ltd.
    Inventors: Rui KURIHARA, Takahiro KAWASHIMA
  • Patent number: 8036254
    Abstract: The output voltage of a cathode drive-type semiconductor laser driving circuit is set to a minimum, power consumption by a driving circuit portion is suppressed, and the heat that is generated by the optical head or the optical disc device is reduced. In addition to a conventional configuration, the semiconductor laser driving circuit of the invention measures the cathode voltage (Vout) of a semiconductor laser (1) and controls the anode voltage (Vld) such that the cathode voltage (Vout) becomes a predetermined level, and by doing so sets the output voltage of the semiconductor laser driving circuit to a predetermined level in order to curtail power consumption by the driving circuit and minimize the rise in temperature of the optical head or the optical disc device.
    Type: Grant
    Filed: June 14, 2006
    Date of Patent: October 11, 2011
    Assignee: Panasonic Corporation
    Inventors: Kenzo Ishibashi, Hisashi Senga, Takeharu Yamamoto
  • Patent number: 8036540
    Abstract: An optical transmitter is disclosed in which the wavelength deviation occurred at the turning on from the disabled state to the enabled state by the negating of the Tx_Disable command is suppressed. The optical transmitter includes a semiconductor laser diode (LD) and an automatic temperature controller (ATC) circuit to drive the thermo-electric cooler (TEC). When the transmitter receives the Tx_Disable to start up the operation of the LD, a pulsed signal is generated in synchronizing with the transition of the Tx_Disable signal to momentarily enhance the cooling capacity of the TEC in order to compensate the increase of the temperature of the LD by the self heating, which prevents the output wavelength of the transmitter from deviating.
    Type: Grant
    Filed: March 10, 2008
    Date of Patent: October 11, 2011
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Moriyasu Ichino
  • Patent number: 8036539
    Abstract: An optical transceiver module configured for longwave optical transmission is disclosed. Significantly, the transceiver module utilizes components formerly used only for shortwave optical transmission, thereby reducing new component production and device complexity. In one embodiment, the transceiver module includes a transmitter optical subassembly including a laser capable of producing an optical signal. A consolidated laser driver/post amplifier including a first bias current source provides a bias current to the laser for producing the optical signal. A means for amplifying the bias current provided to the laser by the first bias current source is also included as a separate component from the laser driver/post amplifier. The means for amplifying in one embodiment is a field-effect transistor that is operably connected to the laser driver/post amplifier and configured to provide an additional bias current to the laser diode such that sufficient lasing operation of the laser is realized.
    Type: Grant
    Filed: June 27, 2006
    Date of Patent: October 11, 2011
    Assignee: Finisar Corporation
    Inventors: Philip Kiely, Minja Trklja, Tim Moran
  • Publication number: 20110235663
    Abstract: A laser light source experiencing an EOL condition, which might otherwise cause an unscheduled shutdown, is instead operated in a diminished capacity in one or more predetermined or calculated increments. Operating in such diminished capacity continues until the laser system can undergo appropriate maintenance either during a regularly scheduled shutdown or a newly scheduled shutdown. In the meantime, the diminished capacity of the laser system is accommodated by the utilization tool, as appropriate.
    Type: Application
    Filed: March 24, 2010
    Publication date: September 29, 2011
    Inventors: Robert P. Akins, Richard L. Sandstrom, Daniel J.W. Brown, Matthew R. Graham, Kevin W. Zhang, Patrick L. Nelissen
  • Publication number: 20110216295
    Abstract: A semiconductor laser driver includes a light detection circuit to detect a quantity of light as a detected light emission intensity and output the detected light emission intensity to the control circuit, and a control circuit to control a light emission intensity for the semiconductor laser based on the detected light emission intensity and on a predetermined light emission intensity setting value. The light detection circuit includes a photoelectric conversion element to convert the quantity of light emitted from the semiconductor laser into an electrical current and output the converted electrical current, a current magnification setting circuit to amplify the electrical current output from the photoelectric conversion element to a predetermined amplified current at one of multiple different predetermined magnifications, a detection resistor to convert the amplified current output from the current magnification setting circuit into a voltage and output the voltage as the detected light emission intensity.
    Type: Application
    Filed: March 4, 2011
    Publication date: September 8, 2011
    Applicant: RICOH COMPANY, LTD.
    Inventor: Hiroaki KYOGOKU
  • Publication number: 20110216794
    Abstract: A laser system is proposed that is configured to provide a pseudo-CW signal at room temperature. The system utilizes an array of pulsed lasers that are controlled (in terms of turning “on” and “off”) to provide, in combination, a quasi-CW output signal. The activation of each individual laser is controlled to turn “on” and “off” in a predefined sequence, where at least one laser is “on” at any given point in time. Thus, by combining the outputs from the plurality of pulsed lasers onto a single output signal path, the resultant output signal from the system will be a pseudo-CW signal (the amount of “ripple” present in the signal controlled by factors such as the number of individual lasers in the plurality of lasers, the duty cycle of each individual laser, etc.). The duty cycle of the individual lasers can be controlled to provide a high power output signal (higher duty cycle), or provide a high wall-plug efficiency of the system (lower duty cycle).
    Type: Application
    Filed: February 22, 2011
    Publication date: September 8, 2011
    Applicant: GK TECHCOM LLC
    Inventors: Scott Howard, Anthony Hoffman
  • Publication number: 20110211605
    Abstract: The present patent application provides a low power consumption pump driving circuit including a laser cooling chip, a PMOS transistor, a NMOS transistor, a LC filter circuit, a laser, and a voltage sampling circuit. The pulse width modulating signal generated by the laser cooling chip and the control terminal of the PMOS transistor are connected to the gate of the PMOS transistor. The source of the PMOS transistor is connected to a power supply. The drain of the PMOS transistor is connected to the LC filter circuit. The other terminal of the LC filter circuit is connected to the anode of the laser. The cathode of the laser is connected to the drain of the NMOS transistor. The source of the NMOS transistor is connected to the ground. One terminal of the voltage sampling circuit is connected to the laser. The other terminal of the voltage sampling circuit is connected to the laser cooling chip.
    Type: Application
    Filed: March 1, 2010
    Publication date: September 1, 2011
    Inventors: Jing Wei Wang, Ai Hua Yu
  • Patent number: 8009710
    Abstract: A laser driver circuit comprising an amplifier device with a plurality of switchable subamplifiers, which can be or are connected to an output for connection of a laser, ith an analog switching device for switching of analog input signals, a plurality of analog inputs for the analog input signals, a plurality of control inputs for receiving digital control signals, wherein each switchable subamplifier has a switching device for switching the amplification by one of the digital control signals, a digital switching device connected to an input of each switching device for the selectable connection of the input of the switching device of each switchable subamplifier to a control input. Whereby each switchable subamplifier has an analog input, which is connected to the analog switching device for the selectable switching of an analog input signal to the analog input.
    Type: Grant
    Filed: August 10, 2009
    Date of Patent: August 30, 2011
    Assignee: Atmel Corporation
    Inventors: Herbert Knotz, Holger Vogelmann, Peter Kolb, Michael Offenwanger, Stefan Schabel
  • Publication number: 20110199657
    Abstract: A laser driving device that drives a semiconductor laser based on a light-emitting signal includes an expansion circuit that expands a pulse width of the light-emitting signal based on a known difference between the pulse width of the light-emitting signal and a lighting pulse width of the semiconductor laser when the semiconductor laser emits light according to the light-emitting signal, and a driver that outputs a driving signal to the semiconductor laser according to an output signal of the expansion circuit.
    Type: Application
    Filed: February 10, 2011
    Publication date: August 18, 2011
    Inventors: Masaaki Ishida, Atsufumi Omori
  • Patent number: 8000359
    Abstract: A laser device capable of preventing deterioration of a light signal and a controlling method therefor are provided.
    Type: Grant
    Filed: December 11, 2008
    Date of Patent: August 16, 2011
    Assignee: Opnext Japan, Inc.
    Inventors: Hiroyasu Sasaki, Hideo Arimoto
  • Patent number: 8000368
    Abstract: Many approaches to tunable lasers use an array of DFBs, where each element of the array has a different wavelength. In some operations one element of the array is activated at a time depending on the desired wavelength. For modulated applications, an RF voltage is applied to a specific element of the DFB array, generally using an RF switch. In standard configurations, the demands on the switch are relatively difficult, generally requiring low RF insertion loss and good high frequency performance to 10 GHz. The DFB arrays are generally common cathode or common anode, depending on the type of the substrate used to fabricate the devices. Described herein is an array with a common cathode or anode configuration using a MEMS based switch that shorts the selected laser to RF ground. With this topology, preferably the off-state capacitance should be low with the MEMS switch.
    Type: Grant
    Filed: July 26, 2007
    Date of Patent: August 16, 2011
    Assignee: Santur Corporation
    Inventors: Bardia Pezeshki, Raghuram Narayan
  • Patent number: 7991032
    Abstract: Disclosed herein is a laser driver including a light emission controlling section configured to stop generation of a control voltage by a control voltage generating section, causing a given voltage corresponding to a magnitude of a reference current to be outputted to an input node of a first emitter follower to operate the first emitter follower for a first time period from start of a light emission time period, release stop of the generation of the control voltage by the control voltage generating section, causing the control voltage to be outputted to the input node of the first emitter follower to operate the first emitter follower until end of the light emission time period of the laser, and operate a second emitter follower to discharge electric charges accumulated in the laser for a second time period after the end of the light emission time period of the laser.
    Type: Grant
    Filed: March 4, 2010
    Date of Patent: August 2, 2011
    Assignee: Sony Corporation
    Inventors: Katsuhisa Daio, Takahiro Tsukada
  • Patent number: 7991031
    Abstract: In a method of controlling an injection-seeded laser, a response of the laser is sampled at a plurality of different laser current values. A threshold current and a slope efficiency of the sampled response are then estimated, and a bias current and a modulation current calculated based on the estimated threshold current and a slope efficiency.
    Type: Grant
    Filed: August 21, 2009
    Date of Patent: August 2, 2011
    Assignee: LG-Ericsson Co., Ltd.
    Inventor: John D. Bainbridge
  • Publication number: 20110181791
    Abstract: The luminance of a laser diode is a function of laser diode drive current. The luminance is also a function of other factors, such as age and temperature. A laser projection device includes laser diodes to generate light in response to a commanded luminance, and also includes photodiodes to provide a measured luminance. The commanded luminance and measured luminance are compared, and drive currents for the laser diodes are adjusted to compensate for changes in laser diode characteristics.
    Type: Application
    Filed: September 30, 2010
    Publication date: July 28, 2011
    Applicant: MICROVISION, INC.
    Inventors: Heng Huang, Mark Champion
  • Patent number: 7986720
    Abstract: A circuit for driving a light-emitting element such as a laser diode LD has a boost circuit for boosting an input voltage to supply it to the light-emitting element, a photoreceptor such as a photodiode PD for monitoring light from the light-emitting element; and a boost control circuit for controlling a boost voltage of the boost circuit based on a monitored amount of the photoreceptor. In the method for driving a light-emitting element by boosting an input voltage to supply the voltage to the light-emitting element, light from the light-emitting element is monitored and its monitored amount is used as a basis to control a boost voltage to the light-emitting element. A control circuit may be provided to control a driving current that passes through the light-emitting element based on the monitored amount of the photoreceptor.
    Type: Grant
    Filed: June 25, 2009
    Date of Patent: July 26, 2011
    Assignee: NEC Corporation
    Inventor: Masashi Tachigori
  • Patent number: 7978741
    Abstract: The invention provides an optical transmitter that prevents the high frequency components in the driving signal from leaking to the external power supply in a wider frequency range. The transmitter provides a shun driving configuration with a switching transistor connected in parallel to the laser diode and a load transistor connected in serial to the parallel circuit of the switching transistor and the laser diode. The load transistor operates in the common base configuration, or the common gate configuration, by which the input impedance viewed from the laser diode becomes large, while, the output impedance viewed from the external power source becomes small. Thus, the high frequency components in the driving signal applied to the switching transistor can be suppresses to appear in the external power source.
    Type: Grant
    Filed: June 11, 2007
    Date of Patent: July 12, 2011
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Katsumi Uesaka