Feedback Circuitry Patents (Class 372/29.011)
  • Patent number: 11862941
    Abstract: A multi-laser arrangement, in particular an RGB laser module, having a housing with a housing cap having at least one opening formed therein and a transparent element associated therewith for the passing of electromagnetic radiation. The housing cap coupled to a base plate. A first laser emitting in the red spectral range, a second laser emitting in the green spectral range, and a third laser emitting in the blue spectral range are arranged in the housing. An electrical connection line is routed through the housing to each respective laser. During operation of a laser, a majority of its emitted light passes through the transparent element. Each laser is arranged on a pedestal; spaced apart from the lower surface of the base plate; and is aligned with one another. The main direction of laser emission is substantially parallel to the base plate of the housing.
    Type: Grant
    Filed: April 20, 2021
    Date of Patent: January 2, 2024
    Assignee: Schott AG
    Inventors: Robert Hettler, Amy Soon Li Ping, Ong Wai Li, Artit Aowudomsuk
  • Patent number: 11509323
    Abstract: A circuit includes an amplifier having first and second inputs and an output, and a feedback circuit configured to generate a feedback voltage in response to a voltage at the output of the amplifier. The feedback circuit is coupled to the first input of the amplifier to provide the feedback voltage to the first input of the amplifier. An output circuit is configured to generate a variable bias current in response to the voltage at the output of the amplifier. A switch circuit is configured to switch the second input of the amplifier from receiving a first reference voltage during a first mode of operation to receiving a second reference voltage during a second mode of operation.
    Type: Grant
    Filed: April 30, 2021
    Date of Patent: November 22, 2022
    Assignee: STMicroelectronics International N.V.
    Inventors: Anand Kumar, Ramji Gupta
  • Patent number: 11431152
    Abstract: The present invention is directed to an ultra-compact dual quantum cascade laser assembly that nearly doubles the strength of a traditional laser in a in a single hermetically sealed micropackage. The device may comprise two quantum cascade lasers that meet at a combiner to create a single laser with a higher strength than traditional lasers. The current invention provides a path to an ultra-compact coherent beam combing arrangement that uses both dichroic beam combining and polarization beam combining techniques.
    Type: Grant
    Filed: June 28, 2021
    Date of Patent: August 30, 2022
    Assignee: PRANALYTICA, INC.
    Inventors: Rodolfo Barron-Jimenez, C. Kumar N. Patel
  • Patent number: 11336073
    Abstract: Disclosed herein is a method comprising injecting light of a first wavelength ?1 into a wavelength division multiplexer; injecting light of a second wavelength ?2 into the wavelength division multiplexer; combining the light of the first wavelength ?1 and the light of the second wavelength ?2 in the wavelength division multiplexer to produce light of a third wavelength ?3; and reflecting the light of the third wavelength ?3 in a dual-Brillouin peak optical fiber that is in communication with the wavelength divisional multiplexer; wherein the dual-Brillouin peak optical fiber has at least two Brillouin peaks, such that an amplitude A1 of at least one of said Brillouin peaks is within 50% to 150% of an amplitude A2 of another Brillouin peak 0.5A2?A1?1.5A2; wherein the dual-Brillouin peak optical fiber generates a Brillouin dynamic grating that reflects an improved back-reflected Brillouin signal of the combined light.
    Type: Grant
    Filed: November 29, 2019
    Date of Patent: May 17, 2022
    Assignee: OFS FITEL, LLC
    Inventors: Kyle R Bedard, Jie Li, Xiaoguang Sun, Man F Yan
  • Patent number: 11201448
    Abstract: The system and method of producing a first path comprising a pulse stretcher for a mid-wave infrared (MWIR) signal, an optical parametric chirped-pulse amplification (OPCPA) amplifier, and a MWIR compressor for producing a first beam in a MWIR portion of the spectrum and a second path comprising a pulse stretcher for a long wave infrared (LWIR) signal, an OPCPA amplifier, and a LWIR compressor for producing a second beam in a LWIR portion of the spectrum. Each beam, on its own, is configured to produce laser-matter interactions at long range (100s of meters), having nonlinear effects and favoring supercontinuum generation spanning multiple octaves, that is temporally and spatially overlapped with the fundamental laser beam.
    Type: Grant
    Filed: December 2, 2020
    Date of Patent: December 14, 2021
    Assignee: BAE Systems Information and Electronic Systems Integration Inc.
    Inventors: Yannick Morel, Peter Budni, Peter Ketteridge, Michael Lemons, Kevin T Werner
  • Patent number: 11050214
    Abstract: In an ultrastable laser, using a large mode-volume optical resonator, which suppresses the resonator's fast thermal fluctuations, together with the stimulated Brillouin scattering (SBS) optical nonlinearity presents a powerful combination that enables the ability to lase with an ultra-narrow linewidth of 20 Hz. The laser's long-term temperature drift is compensated by using the narrow Brillouin line to sense minute changes in the resonator's temperature (e.g., changes of 85 nK). The precision of this temperature measurement enables the stabilization of resonators against environmental perturbations.
    Type: Grant
    Filed: May 2, 2019
    Date of Patent: June 29, 2021
    Assignee: Massachusetts Institute of Technology
    Inventors: William Loh, Paul William Juodawlkis, Siva Yegnanarayanan
  • Patent number: 10884235
    Abstract: A drawing apparatus includes a laser light source unit configured to output laser light; a scanning mirror unit configured to reflect and scan the laser light; a drawing control unit configured to control an output value of the laser light of the laser light source unit based on display image data so that a display image is drawn by the laser light in a range scanned by the scanning mirror unit; and an output adjustment control unit configured to control the laser light source unit so that characteristic detection laser light for adjusting the output value of the laser light is output outside a range in which the display image is drawn inside the range scanned by the scanning mirror unit. The output adjustment control unit controls the characteristic detection laser light to be intermittently output in one frame period.
    Type: Grant
    Filed: March 9, 2018
    Date of Patent: January 5, 2021
    Assignee: JVCKENWOOD Corporation
    Inventor: Tatsuya Ohara
  • Patent number: 10739256
    Abstract: A light ranging and detection system achieving reconfigurable very wide field of view, high sampling of spatial points per second with high optical power handling by using architecture to efficiently combine different wavelengths, time and frequency coding, and spatial selectivity. The transmitter is capable of generating multiple narrow beams, encoding different beams and transmitting in different spatial directions. The receiver can differentiate and extract range and reflectivity information of reflected beams. Three dimensional imaging of the environment is achieved by scanning the field of view of the transmitter. Control and signal processing electronic circuitries fabricated in a chip are packaged together with a chip containing the photonic components of the ranging system. The light ranging and detection system generates a THz beam in addition to an optical beam, and both beams combined allow reconfigurable spectroscopy.
    Type: Grant
    Filed: March 29, 2019
    Date of Patent: August 11, 2020
    Assignee: ROCKLEY PHOTONICS LIMITED
    Inventors: Andrew George Rickman, Hooman Abediasl
  • Patent number: 10693276
    Abstract: An optical transmitter includes: a semiconductor laser unit that outputs laser light of first output power and outputs a monitor current; a casing of an optical module that holds optical fiber; a monitor current detection unit that generates a monitor voltage; a laser driving unit that controls a laser driving current; a storage unit that stores information based on a result of a measurement of a ratio of second output power with respect to the first output power; a target voltage determination unit that changes the target voltage based on a detected temperature of a temperature sensor and the information based on the result of the measurement; and a power monitor value determination unit that generates a power monitor value indicating the second output power to be transmitted to a host device using the detected temperature and the information based on the result of the measurement.
    Type: Grant
    Filed: March 31, 2017
    Date of Patent: June 23, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Eitetsu Igawa, Hiroyuki Ozaki, Satoshi Ishitobi
  • Patent number: 10684170
    Abstract: A terahertz spectrometer includes: a terahertz-wave emitter and a terahertz receiver elements. The terahertz wave generated by means of generating beat frequency corresponding to the difference between two rapidly tunable continuous wave lasers. Having a difference in time between the interrogating signal and the reference signal at the receiver end side, which corresponds to intermediate frequency (IF), not centered around the baseband, i.e. zero Hertz. The offset step size of the intermediate frequency from zero Hertz is linearly correlated to the position of the interrogated object position.
    Type: Grant
    Filed: May 1, 2018
    Date of Patent: June 16, 2020
    Assignee: NOVATRANS GROUP SA
    Inventors: John F. Roulston, Daniel Mandelik
  • Patent number: 10673209
    Abstract: A QCL may include a substrate, and a semiconductor layer adjacent the substrate and defining an active region. The active region may have an elongate shape extending laterally across the substrate and having a number of stages greater than 25, each stage having a thickness less than 40 nanometers. The active region may have a ridge width greater than 15 ?m.
    Type: Grant
    Filed: July 9, 2018
    Date of Patent: June 2, 2020
    Assignee: UNIVERSITY OF CENTRAL FLORIDA RESEARCH FOUNDATION, INC.
    Inventors: Arkadiy Lyakh, Matthew Suttinger
  • Patent number: 10630391
    Abstract: RF processing systems and methods. An RF processing system includes an optical storage module, a processing module, and an electro-optical modulation module. The electro-optical modulation module is configured to receive the first signal from the optical storage module, receive the modulation signal from the processing module, and electro-optically modulate the first signal based on the modulation signal.
    Type: Grant
    Filed: November 21, 2018
    Date of Patent: April 21, 2020
    Assignee: MagiQ Technologies, Inc.
    Inventors: Michael LaGasse, Alan Craig Beal, Mark David Lucas
  • Patent number: 10630046
    Abstract: A laser light adjusting method includes detecting a pair of mode hops and a comparison saturated absorption line group of the pair of mode hops based on an intensity of a light output signal in response to a change applied to an actuator, comparing a mode center voltage value with a comparison voltage value which is the voltage value at which the comparison saturated absorption line group was generated; a control temperature adjustment process that increases a control temperature when the comparison voltage value is lower than the mode center voltage value, and that decreases the control temperature of the temperature adjuster when the comparison voltage value is greater than the mode center voltage value; and a laser light stabilization step that stabilizes an emission frequency of the laser light to a specific saturated absorption line after the control temperature adjustment process.
    Type: Grant
    Filed: February 21, 2019
    Date of Patent: April 21, 2020
    Assignee: MITUTOYO CORPORATION
    Inventor: Yusuke Shirakawa
  • Patent number: 10520759
    Abstract: An opto-electronic oscillator (10) comprising: an optical source (12) to generate an optical carrier signal having a carrier wavelength; an optical phase modulator (14) to apply a sinusoidal phase modulation to the optical carrier signal to generate two first order sidebands having a ? phase difference between them; an optical phase shifter (16) comprising an optical resonator configured to apply a substantially ? phase-shift to one of the first order sidebands at a preselected wavelength within an optical spectrum of said first order sideband; and a photodetector (18) configured to perform optical heterodyne detection of the optical carrier signal with both: said one of the first order sidebands substantially it phase shifted by the optical resonator; and the other of the first order sidebands, to generate an electrical carrier signal (20), and wherein a first part of the electrical carrier signal (20a) is delivered to an electrical output (22) and a second part of the electrical carrier signal (20b) is deli
    Type: Grant
    Filed: January 7, 2016
    Date of Patent: December 31, 2019
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Marzio Puleri, Antonella Bogoni, Claudio Porzi, Antonio D'Errico, Paolo Ghelfi, Giovanni Serafino, Vito Sorianello
  • Patent number: 10476225
    Abstract: Disclosed is an injected laser including an optical amplifying medium arranged inside a triggered laser cavity, the optical amplifying medium having a spectral amplifying band. The injected laser includes an optical phase-modulation device, arranged between the injection source and the laser cavity, the optical phase-modulation device being configured to periodically modulate as a function of time a phase of the monochromatic continuous laser radiation at a modulation frequency equal to a natural integer multiple of the free spectral range of the laser cavity, so that the phase-modulated injection source generates a polychromatic injection radiation.
    Type: Grant
    Filed: July 6, 2016
    Date of Patent: November 12, 2019
    Assignee: COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
    Inventors: Denis Penninckx, Jacques Luce, Romain Diaz, Odile Bonville, Roger Courchinoux
  • Patent number: 10447008
    Abstract: A laser driver device is provided, which includes a control circuit, a driver circuit and a feedback circuit. The control circuit receives setup data and convert the setup data into a setup signal. The driver circuit receives the setup signal and generates a drive current according to the setup signal to drive a laser light source. The feedback circuit receives the setup data and the feedback signal of the laser light source and compares the setup data with the feedback signal to generate an adjust signal. The driver circuit receives the adjust signal and adjusts the drive current according to the adjust signal.
    Type: Grant
    Filed: October 10, 2018
    Date of Patent: October 15, 2019
    Assignee: INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE
    Inventors: Yu-Cheng Song, Chih-Chun Chen, Fu-Shun Ho, Chien-Hung Lu
  • Patent number: 10367597
    Abstract: A method for establishing an embedded optical communication channel in an optical WDM transmission system including: creating, at the central network device, a broad-band optical signal, supplying the broadband optical signal, transmitting the broadband optical signal and the plurality of second optical channel signals to an optical demultiplexer device, transmitting an optical signal consisting of a dedicated second optical channel signal and a filtered broadband optical signal; receiving the optical signal and creating a corresponding electrical receive signal and extracting the electrical signal corresponding to the filtered broadband optical signal from the electrical receive signal and detecting whether the electrical signal contains information intended for the respective first channel transceiver.
    Type: Grant
    Filed: June 29, 2017
    Date of Patent: July 30, 2019
    Assignee: ADVA Optical Networking SE
    Inventor: Stephan Pachnicke
  • Patent number: 10320148
    Abstract: The present invention relates to a diode laser with external spectrally selective feedback. It is an object of the invention is to provide an external cavity diode laser with wavelength stabilization which allows an increased overall output power in the desired wavelength range.
    Type: Grant
    Filed: September 16, 2015
    Date of Patent: June 11, 2019
    Assignee: Highyag LaserTechnologie GmbH
    Inventors: Haro Fritsche, Ralf Koch, Bastian Kruschke, Fabio Ferrario
  • Patent number: 10211943
    Abstract: A wavelength division multiplexing, WDM, network comprising an apparatus adapted to manage a frequency spectrum in the wavelength division multiplexing, WDM, network, the apparatus comprising an adjustment unit adapted to adjust a frequency offset between carriers for each individual carrier depending on performance characteristics of the individual carriers.
    Type: Grant
    Filed: January 20, 2017
    Date of Patent: February 19, 2019
    Assignee: ADVA OPTICAL NETWORKING SE
    Inventors: Paul Morkel, Sorin Tibuleac
  • Patent number: 10148062
    Abstract: A laser light source device has a semiconductor laser element, a heat transfer portion having thermal conductivity and connected to the semiconductor laser element, a cooler connected to the heat transfer portion on a side different from the semiconductor laser element, a control object temperature measurement section that measures a control object temperature as the temperature of the heat transfer portion or the cooler, an environmental temperature measurement section that measures an environmental temperature of the laser light source device, and a controller that controls the cooler. The controller is configured to control the cooler such that the control object temperature approaches a predetermined target temperature set according to the environmental temperature. The target temperature set when the environmental temperature is lower than a specific temperature is lower than the target temperature set when the environmental temperature is higher than the specific temperature.
    Type: Grant
    Filed: October 4, 2016
    Date of Patent: December 4, 2018
    Assignee: USHIO DENKI KABUSHIKI KAISHA
    Inventor: Akihiro Shimizu
  • Patent number: 10014649
    Abstract: A stabilized laser source includes a fiber-ring Brillouin laser that incorporates a circulator for non-reciprocal operation and for launching of a pump optical signal. Most of the pump optical signal is launched in a forward direction and drives Brillouin laser oscillation in the backward direction, a portion of which exits via an optical coupler as the optical output of the laser source. A small fraction of the pump optical signal is launched in the backward direction via the optical coupler, and a fraction of that backward-propagating pump optical signal exits via the optical coupler as an optical feedback signal. A frequency-locking mechanism receives the optical feedback signal and controls the pump optical frequency to maintain resonant propagation of the backward-propagating pump optical signal. A second pump optical signal can be launched in the forward direction to generate a second Brillouin laser oscillation.
    Type: Grant
    Filed: December 21, 2016
    Date of Patent: July 3, 2018
    Assignees: CALIFORNIA INSTITUTE OF TECHNOLOGY, HQPHOTONICS INC.
    Inventors: Jiang Li, Kerry Vahala
  • Patent number: 9985409
    Abstract: A calculation part calculates a maximum temperature reached which is reached by the coolant or component of each part, in the case of machining in accordance with laser machining conditions that were inputted or set, based on the cooling capacity of a chiller, tank volume of the chiller, heat generation amount from the laser oscillator, heat capacity of a cooled part of the laser device, etc. which are recorded in a recording part, and the temperature of each part measured by temperature detection parts, etc. In the case that the maximum temperature reached would exceed the allowed maximum temperature, a warning is made prior to starting laser machining.
    Type: Grant
    Filed: April 10, 2017
    Date of Patent: May 29, 2018
    Assignee: FANUC CORPORATION
    Inventors: Hiroshi Takigawa, Yuji Nishikawa
  • Patent number: 9929529
    Abstract: A solid-state laser system may include a first solid-state laser unit, a second solid-state laser unit, a wavelength conversion system, a wavelength detector, and a wavelength controller. The wavelength conversion system may receive a first pulsed laser light beam with a first wavelength and a second pulsed laser light beam with a second wavelength, and output a third pulsed laser light beam with a third wavelength converted from the first and second wavelengths. The wavelength controller may control the first solid-state laser unit to vary the first wavelength on a condition that an absolute value of a difference between a value of a target wavelength and a value of the third wavelength detected by the wavelength detector is equal to or less than a predetermined value, and control the second solid-state laser unit to vary the second wavelength on a condition that the absolute value exceeds the predetermined value.
    Type: Grant
    Filed: August 9, 2017
    Date of Patent: March 27, 2018
    Assignee: Gigaphoton Inc.
    Inventors: Takashi Onose, Osamu Wakabayashi
  • Patent number: 9825422
    Abstract: An optic-microwave frequency discriminator includes: a fiber coupler receives and combines a first laser and a second laser, than the fiber coupler respectively generates and outputs a first light signal and a second light signal; a photodiode module respectively receives the first light signal and the second light signal, and converts the first light signal into a first microwave signal and converts the second light signal into a second microwave signal; a microwave phase shifter generates a shifted microwave signal by introducing a phase shift to the second microwave signal; a 90° microwave bridge combines the first microwave signal and the shifted microwave signal for generating a first bridge signal and a second bridge signal; a normalized balanced detection module generates an error signal; and a control module generates a controlling voltage signal according to the error signal for tuning a frequency of the second laser.
    Type: Grant
    Filed: May 3, 2016
    Date of Patent: November 21, 2017
    Assignees: Zibo Qi-red PhotoElectrical Technology Co., Ltd., Beijing Qi-red PhotoElectrical Technology Co., Ltd.
    Inventors: Shudong Wu, Wenbo Wang
  • Patent number: 9806843
    Abstract: The invention relates to a method for creating a control channel in an optical transmission signal, wherein the optical transmission signal (SDS,i, SUS,i) includes an optical carrier frequency component, a higher frequency modulation component carrying user information to be transported from a first end to a second end of an optical transmission link and a lower frequency modulation component carrying control information, the higher frequency modulation component realizing a user channel and the lower frequency modulation component realizing the control channel, and wherein the lower frequency modulation component is created by amplitude modulation. According to the invention, the lower frequency modulation component includes a binary digital pilot tone signal component which corresponds to a pilot tone signal having a predetermined pilot tone frequency (fi).
    Type: Grant
    Filed: April 4, 2016
    Date of Patent: October 31, 2017
    Assignee: Adva Optical Networking SE
    Inventor: Michael Eiselt
  • Patent number: 9762019
    Abstract: A method and a device is provided driving an optical laser diode (710, 711) during operation in an optical communication network, by determining a laser transfer function (741, 742) during operation of the laser diode (710, 711) and providing a control signal (750, 749) for driving the laser diode (710, 711) according to the laser transfer function (741, 742). Further, a method for driving a first and a second optical laser diode during operation in an optical communication network is provided. Furthermore, an optical amplifier and a communication system is suggested.
    Type: Grant
    Filed: April 25, 2014
    Date of Patent: September 12, 2017
    Assignee: Xieon Networks S.a.r.l.
    Inventors: Lutz Rapp, Guido Gentner
  • Patent number: 9743840
    Abstract: A flash lamp 32 excites a laser rod 31. A Q switch 35 which changes the loss of the optical resonator according to the voltage applied is inserted on the optical path of a pair of mirrors 33 and 34 forming the optical resonator. An optical path shutter 39 is provided on the optical path of laser emission light. In a first operation mode in which laser emission is performed, the optical path shutter 39 is opened and the voltage applied to the Q switch 35 is changed from a high voltage to, for example, 0 V to emit pulsed laser light after the flash lamp 32 excites the laser rod 31. In a second operation mode in which the laser emission is interrupted and waited for, the optical path shutter 39 is closed and the voltage applied to the Q switch 35 is, for example, 0 V.
    Type: Grant
    Filed: July 16, 2015
    Date of Patent: August 29, 2017
    Assignee: FUJIFILM Corporation
    Inventors: Kazuhiro Hirota, Tadashi Kasamatsu
  • Patent number: 9653879
    Abstract: The disclosure provides an optical module, including a laser, the laser including a light emitting region and a modulation region, and light emitted by the light emitting region emitting toward the modulation region; a first driver circuit, the first driver circuit being connected to the light emitting region, so that the light emitting region emits light with adjusted optical power; and a second driver circuit, the second driver circuit being connected to the modulation region, so that the modulation region changes the optical power of the light emitted from the light emitting region.
    Type: Grant
    Filed: March 31, 2016
    Date of Patent: May 16, 2017
    Assignees: Hisense Broadband Multimedia Technologies, Ltd., Hisense USA Corp., Hisense International Co., Ltd.
    Inventors: Qiang Zhang, Qisheng Zhao, Shihai Yang
  • Patent number: 9653878
    Abstract: A dual-rate power point compensating circuit, comprising a microprocessor and a transmitter optical subsystem assembly (TOSA), wherein the TOSA includes a laser connected to a laser driver, a monitor photodiode (MPD) connected to the laser driver, and a current divider connected to the microprocessor and the MPD. When a feedback current from the MPD exceeds the adjustable and/or operating range of the laser driver, the feedback current is reduced so that it is kept in the adjustable and/or operating range of the laser driver. The laser driver determines the optical output power of the laser from the value of the reduced feedback current. The circuit and method extend the adjustable and/or operating range of a laser driver and enable it to regulate a target optical output power of the laser with a broad testing range and high accuracy when the feedback current is relatively high.
    Type: Grant
    Filed: December 23, 2014
    Date of Patent: May 16, 2017
    Assignee: Source Photonics (Chengdu) Co., Ltd.
    Inventors: Chaobo Jia, Yuanjun Huang, Yuanzhong Xu
  • Patent number: 9509967
    Abstract: To avoid accelerated progression of deterioration of a semiconductor laser, an LED, and the like to extend their lives while adjusting a balance of a plurality of colors, such as R, G, and B, by feedback control, a deterioration controllable monochromatic light source module is configured to: calculate a substantial upper limit Iu, determine an operation coefficient hx based on a deterioration coefficient dx, perform feedback control of the output current Ix of each drive circuit, and output a light intensity detection signal to the outside. An integrating control circuit calculates a monochromatic light intensity sum ? by a sum of light intensity detection signals from the monochromatic light source modules belonging to the same wavelength band and determines a light intensity target signal so that a ratio of the monochromatic light intensity sum ? to the monochromatic light source modules in different wavelength bands is a predetermined ratio.
    Type: Grant
    Filed: September 19, 2014
    Date of Patent: November 29, 2016
    Assignee: Ushio Denki Kabushiki Kaisha
    Inventors: Takanori Samejima, Fumihiko Oda, Masashi Okamoto
  • Patent number: 9448039
    Abstract: A target marking system includes a light source emitting a thermal beam and an optics assembly directing the thermal beam to impact a target, the target directing radiation to the optics assembly in response to the impact. The target marking system further includes a detector, and an optics assembly optically connected to the detector.
    Type: Grant
    Filed: September 23, 2015
    Date of Patent: September 20, 2016
    Assignee: LaserMax, Inc.
    Inventors: Susan Houde-Walter, Daniel Joseph Balonek, Michael Wade Allen, William R. Houde-Walter, Brian L. Olmsted
  • Patent number: 9425584
    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: Grant
    Filed: April 22, 2014
    Date of Patent: August 23, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Daisuke Akagi
  • Patent number: 9197328
    Abstract: An optical transmitter implemented with two QPSK (Quadrature Phase Shift Keying) modulators is disclosed. Each of the QPSK modulators provides a waveguide made of semiconductor material inducing the QCSE (Quantum Confined Stark Effect) by a bias supplied thereto. The optical performance of one of the QPSK modulators is determined by supplying a deep bias to the other of the QPSK modulator to eliminate the optical output therefrom.
    Type: Grant
    Filed: February 14, 2013
    Date of Patent: November 24, 2015
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Shingo Yamanaka
  • Patent number: 9039207
    Abstract: A method for providing a feedback circuit for a three dimensional projector. First and second input devices and a sensor for determining the rotational speed of the second input device are provided. A control device for controlling the rotational speed of the second input device and a phase locked loop (PLL) are provided. A phase reference signal is created based on the signal rate of the first input device. A phase signal is created based on the rotational speed of the second input device. The PLL compares the phase reference signal and the phase feedback signal to determine whether the first input device and the second input device are synchronized. A signal is sent to the control device for the second input device to change the rotational speed of the second input device in response to determining that the first input device and the second input device are not synchronized.
    Type: Grant
    Filed: November 9, 2012
    Date of Patent: May 26, 2015
    Assignee: International Business Machines Corporation
    Inventor: Casimer M. DeCusatis
  • Patent number: 9031103
    Abstract: The existing diodes in an LED or laser diode package are used to measure the junction temperature of the LED or laser diode. The light or laser emissions of a diode are switched off by removing the operational drive current applied to the diode package. A reference current, which can be lower the operational drive current, is applied to the diode package. The resulting forward voltage of the diode is measured using a voltage measurement circuit. Using the inherent current-voltage-temperature relationship of the diode, the actual junction temperature of the diode can be determined. The resulting forward voltage can be used in a feedback loop to provide temperature regulation of the diode package, with or without determining the actual junction temperature. The measured forward voltage of a photodiode or the emissions diode in a diode package can be used to determine the junction temperature of the emissions diode.
    Type: Grant
    Filed: November 5, 2013
    Date of Patent: May 12, 2015
    Assignee: Microsoft Technology Licensing, LLC
    Inventors: Leo Del Castillo, Dawson Yee
  • Patent number: 9016873
    Abstract: A method for providing a feedback circuit for a three dimensional projector. First and second input devices and a sensor for determining the rotational speed of the second input device are provided. A control device for controlling the rotational speed of the second input device and a phase locked loop (PLL) are provided. A phase reference signal is created based on the signal rate of the first input device. A phase signal is created based on the rotational speed of the second input device. The PLL compares the phase reference signal and the phase feedback signal to determine whether the first input device and the second input device are synchronized. A signal is sent to the control device for the second input device to change the rotational speed of the second input device in response to determining that the first input device and the second input device are not synchronized.
    Type: Grant
    Filed: October 25, 2013
    Date of Patent: April 28, 2015
    Assignee: International Business Machines Corporation
    Inventor: Casimer M. DeCusatis
  • Patent number: 9004700
    Abstract: A projector system that includes a first input device, a second input device, a control device, a sensor and a phase locked loop (PLL). A phase reference signal is created based on a signal rate of the first input device. A phase feedback signal is created based on the rotational speed of the second input device as it is measured by the sensor. The PLL compares the phase reference signal and the phase feedback signal to determine whether the first input device and the second input device are synchronized. A signal is sent to the control device for the second input device to change the rotational speed of the second input device in response to determining that the first input device and the second input device are not synchronized.
    Type: Grant
    Filed: January 25, 2012
    Date of Patent: April 14, 2015
    Assignee: International Business Machines Corporation
    Inventor: Casimer M. DeCusatis
  • 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: 8982917
    Abstract: A control circuit measures fluctuations in the energy of a pulse laser with respect to the power of an RF signal by varying the power of the RF signal, determines the minimum power of the RF signal which yields a permissible level of fluctuation, and sets the power of the RF signal based on the minimum power of the RF signal. Heat generation in the RF signal generation circuit can be suppressed, and the overall power consumption can also be reduced. It is also possible to reduce the time from when the RF signal is turned on until the RF signal is turned off. As a result, it is possible to generate a stable pulse laser.
    Type: Grant
    Filed: May 29, 2013
    Date of Patent: March 17, 2015
    Assignee: Shimadzu Corporation
    Inventors: Shingo Uno, Naoya Ishigaki
  • Publication number: 20150070756
    Abstract: A laser source (10) for emitting an output beam (12) along an output axis (12A) includes (i) a first laser module (16) that generates a first beam (16A); (ii) a second laser module (18) that generates a second beam (18A); (iii) a beam selector assembly (32); (iv) a first director assembly (24) that directs the first beam (16A) at the beam selector assembly (32); (v) a second director assembly (26) that directs the second beam (18A) at the beam selector assembly (32); and (vii) a control system (34) that directs power to the modules (16), (18). The beam selector assembly (32) moves between a first position in which the first beam (16A) is directed along the output axis (12A), and a second position in which the second beam (18A) is directed along the output axis (12A).
    Type: Application
    Filed: July 23, 2013
    Publication date: March 12, 2015
    Applicant: Daylight Solutions, Inc.
    Inventors: J. Allen Priest, Santino Marrone, David Caffey, David Amone, Michael Pushkarsky
  • Patent number: 8976822
    Abstract: Opto-electronic oscillator (OEO) devices include an optical resonator filter to block the strong laser light at the laser carrier frequency from entering the optical resonator filter and to select one of the weak modulation sidebands, which is in resonance with the optical resonator filter, to be coupled into the optical resonator filter. The laser light at the laser carrier frequency and other modulation sidebands bypass the optical resonator filter to reach a fast photodetector. The laser light in the selected modulation sideband in the optical resonator filter is then coupled out to mix with the laser light at the laser carrier frequency and other modulation sidebands at the fast photodetector to produce the detector output as the input to the electrical part of the opto-electronic loop to produce the OEO oscillation.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: March 10, 2015
    Assignee: OEwaves, Inc.
    Inventors: Lute Maleki, David Seidel, Vladimir Ilchenko, Danny Eliyahu, Anatoliy Savchenkov, Andrey Matsko
  • Publication number: 20150036705
    Abstract: The method for controlling a wavelength-tunable laser comprises a first step of acquiring a driving condition of the wavelength-tunable laser for laser oscillation at a first wavelength, and a second step of calculating according to the driving condition of the first wavelength and a wavelength difference between the first wavelength and a second wavelength different from the first wavelength a control value or target value of a wavelength characteristic of the second wavelength in the wavelength detection unit, so as to calculate a driving condition for driving the wavelength-tunable laser, the second step including a step of selecting according to the wavelength difference one of etalon slopes having respective gradients identical and opposite to a gradient of an etalon slope used for controlling the first wavelength.
    Type: Application
    Filed: July 30, 2014
    Publication date: February 5, 2015
    Inventors: Hirokazu TANAKA, Masao SHIBATA, Mitsuyoshi MIYATA
  • Patent number: 8923352
    Abstract: One embodiment is directed towards a stabilized laser including a laser to produce light at a frequency and a resonator coupled to the laser such that the light from the laser circulates therethrough. The laser also includes Pound-Drever-Hall (PDH) feedback electronics configured to adjust the frequency of the light from the laser to reduce phase noise in response to light sensed at the reflection port of the resonator and transmission port feedback electronics configured to adjust the frequency of the light from the laser toward resonance of the resonator at the transmission port in response to the light sensed at the transmission port of the resonator, wherein the transmission port feedback electronics adjust the frequency at a rate at least ten times slower than the PDH feedback electronics.
    Type: Grant
    Filed: August 10, 2012
    Date of Patent: December 30, 2014
    Assignee: Honeywell International Inc.
    Inventors: Lee K. Strandjord, Tiequn Qiu, Glen A. Sanders
  • Patent number: 8913637
    Abstract: A highly portable, high-powered infrared laser source is produced by intermittent operation of a quantum cascade laser power regulated to a predetermined operating range that permits passive cooling. The regulation process may boost battery voltage allowing the use of a more compact, low-voltage batteries.
    Type: Grant
    Filed: January 4, 2013
    Date of Patent: December 16, 2014
    Assignee: Daylight Solutions, Inc.
    Inventors: Rob Marsland, Timothy Day
  • Publication number: 20140355632
    Abstract: A control circuit measures fluctuations in the energy of a pulse laser with respect to the power of an RF signal by varying the power of the RF signal, determines the minimum power of the RF signal which yields a permissible level of fluctuation, and sets the power of the RF signal based on the minimum power of the RF signal. Heat generation in the RF signal generation circuit can be suppressed, and the overall power consumption can also be reduced. It is also possible to reduce the time from when the RF signal is turned on until the RF signal is turned off. As a result, it is possible to generate a stable pulse laser.
    Type: Application
    Filed: May 29, 2013
    Publication date: December 4, 2014
    Applicant: SHIMADZU CORPORATION
    Inventors: Shingo UNO, Naoya ISHIGAKI
  • Publication number: 20140346358
    Abstract: A highly portable, high-powered infrared laser source is produced by intermittent operation of a quantum cascade laser power regulated to a predetermined operating range that permits passive cooling. The regulation process may boost battery voltage allowing the use of a more compact, low-voltage batteries.
    Type: Application
    Filed: January 4, 2013
    Publication date: November 27, 2014
    Applicant: DAYLIGHT SOLUTIONS, INC.
    Inventor: DAYLIGHT SOLUTIONS, INC.
  • Patent number: 8885679
    Abstract: Embodiments of the invention describe integrating a phase shifting component into a cavity of a laser. Said phase shifter is capable of a continuous phase shift at a single wavelength over a large range (where the maximum energy consumption of the phase shifting component does not scale with the phase shifting range). In other words, said phase shifter is used to form a configurable optical cavity length for a laser. Embodiments of the invention thus utilize a plurality of optical cavity lengths—including one or more optical cavity lengths to potentially shift the phase of the output optical signal, to maintain a laser cavity's output wavelength and avoid spatial mode-hops in the presence of fluctuations such as temperature drift or changes to the drive current of the laser.
    Type: Grant
    Filed: May 31, 2013
    Date of Patent: November 11, 2014
    Assignee: Aurrion, Inc.
    Inventors: Jonathan Edgar Roth, Gregory Alan Fish, Erik Johan Norberg, Robert Silvio Guzzon, Brian R. Koch
  • 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: 20140328359
    Abstract: A laser light generator emits laser light, a frequency of which can be adjusted. A laser light detector bombards an iodine cell with the laser light and photoelectrically converts the laser light that has passed through the iodine cell, then outputs a light output signal. A third order differential lock-in amplifier generates a third order differential signal of the light output signal. A frequency locker causes the laser light generator to change the frequency of the laser light within a predetermined range, detects an amplitude corresponding to a saturated absorption line occurring in the third order differential signal, and causes the frequency of the laser light to stabilize to a predetermined value. An error detector outputs an error signal in a case where the amplitude corresponding to the saturated absorption line occurring in the third order differential signal is greater than a predetermined value.
    Type: Application
    Filed: April 28, 2014
    Publication date: November 6, 2014
    Applicant: MITUTOYO CORPORATION
    Inventor: Ryunosuke YANO