Modulation Patents (Class 372/26)
  • Patent number: 7881357
    Abstract: In a vertical cavity surface-emitting semiconductor laser device, first and second resonance wavelengths which are different are provided while a first resonator and a second resonator are coupled optically, and a gain of an active layer at the first resonance wavelength on the side of short wavelength is higher than that at the second resonance wavelength on the side of long wavelength. An absorption coefficient of an optical absorption layer when no electric field is applied is small for the first and second resonance wavelengths, and when an electric field is applied, an absorption coefficient of the optical absorption layer for the first resonance wavelength on the side of short wavelength is larger than that for the second resonance wavelength on the side of long wavelength.
    Type: Grant
    Filed: May 14, 2008
    Date of Patent: February 1, 2011
    Assignee: Ricoh Company, Ltd.
    Inventor: Takashi Takahashi
  • Patent number: 7881566
    Abstract: An improved laser source for use in a distributed temperature sensing (DTS) system (and DTS systems employing the same) includes a laser device and drive circuitry that cooperate to emit an optical pulse train at a characteristic wavelength between 1050 nm and 1090 nm. An optical amplifier, which is operably coupled to the laser device, is adapted to amplify the optical pulse train for output over the optical fiber sensor of the DTS system. In the preferred embodiment, the laser device operates at 1064 nm and outputs the optical pulse train via an optical fiber pigtail that is integral to its housing. The optical power of the optical pulse train generated by the laser source is greater than 100 mW, and preferably greater than 1 W, at a preferred pulse repetition frequency range between 1 and 50 kHz, and at a preferred pulse width range between 2 and 100 ns.
    Type: Grant
    Filed: January 10, 2006
    Date of Patent: February 1, 2011
    Assignee: Schlumberger Technology Corporation
    Inventors: Gareth P. Lees, Arthur H. Hartog, Peter C. Wait
  • Publication number: 20110019705
    Abstract: Output pulses from an optical system having a seed source and an optical amplifier coupled to the seed source may be controlled by controlling a power of a seed signal from the seed source. The seed signal may be varied between a minimum value and a maximum value in a way that the seed signal exhibits one or more pulse bursts. Each pulse burst may contain one or more pulses. During an inter-pulse period between successive pulses within a pulse burst or between successive pulse bursts, the power of the seed signal may be adjusted to an intermediate value that is greater than the minimum value and less than the maximum value. The intermediate value is chosen to control a gain in the optical amplifier such that a pulse or pulse burst that follows the period exhibits a desired behavior.
    Type: Application
    Filed: July 21, 2009
    Publication date: January 27, 2011
    Applicant: MOBIUS PHOTONICS, INC.
    Inventors: Frank J. Adams, Manuel J. Leonardo, David L. Klein
  • Patent number: 7869472
    Abstract: Techniques and devices for providing optical locking of optical resonators and lasers.
    Type: Grant
    Filed: March 11, 2009
    Date of Patent: January 11, 2011
    Assignee: OEwaves, Inc.
    Inventors: Lute Maleki, Andrey B. Matsko, Anatoliy Savchenkov, Vladimir Ilchenko, Wei Liang, David Seidel, Jerry Byrd
  • Publication number: 20110002029
    Abstract: An optical clock for generating a series of optical clock pulses, comprises a laser source for generating output having a plurality of spectral components ?1, ?2, . . . ?N, an amplitude-modulator arranged to cooperate with the laser source to produce a series of intermediate optical pulses each having the plurality of spectral components, and optical fibre arranged to provide dispersion of each intermediate optical pulse to form a plurality of component pulses each corresponding to a spectral component and to compress each component pulse, the spectral width of each spectral component being sufficient to inhibit stimulated Brillouin scattering (SBS) of the component pulses within the optical fibre. The optical clock may be used for analogue-to-digital conversion of an electrical signal, in which application pulses of respective spectral components are demultiplexed and subsequently detected and digitised in parallel, providing for faster conversion.
    Type: Application
    Filed: March 9, 2009
    Publication date: January 6, 2011
    Applicant: QINETIQ LIMITED
    Inventor: Gregor John McDonald
  • Patent number: 7864820
    Abstract: A laser light source device is disclosed, which reduces the coherence of the laser light and inexpensively achieves a visually recognizable level of speckle reduction without use of a mechanical driving means. The laser light source device includes: laser modules, each including a laser light source, an intensity modulation unit to apply intensity modulation to laser light emitted from the laser light source, and a first waveguide to receive the intensity-modulated laser light from the laser light source and output the laser light from an output end thereof; and a second waveguide including an input end optically connected to a light outputting area of the first waveguides to receive the laser light outputted from the first waveguides, the first waveguides being closely bundled in the vicinity of output ends thereof, wherein a core of the second waveguide at the input end is larger than the light outputting area.
    Type: Grant
    Filed: March 25, 2009
    Date of Patent: January 4, 2011
    Assignee: FUJIFILM Corporation
    Inventor: Shinichi Shimotsu
  • Publication number: 20100322271
    Abstract: A method to control an LD (laser diode) is disclosed. The method compares the operating temperature of the LD with a transition temperature. When the former temperature exceeds the latter, the modulation current is set based on the bias current, which is independently determined by the APC loop. On the other hand, the operating temperature is less than the transition temperature; the modulation current is determined by the operating temperature.
    Type: Application
    Filed: June 17, 2010
    Publication date: December 23, 2010
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Moriyasu ICHINO, Hiroto Ishibashi, Toru Ukai, Yuanzhe Li
  • Patent number: 7852899
    Abstract: Feedback timing control equipment and process for an injection seeded modular gas discharge laser. A preferred embodiment is a system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 to 10 mJ or greater for integrated outputs of about 20 to 40 Watts or greater. The feedback timing control is programmed to permit in some circumstances discharges timed so that no significant laser energy is output from the system. Use of this technique permits burst mode operation in which the first discharge of a burst is a no-output discharge so that timing parameters for each of the two chambers can be monitored before the first laser output pulse of the burst. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber.
    Type: Grant
    Filed: July 6, 2006
    Date of Patent: December 14, 2010
    Assignee: Cymer, Inc.
    Inventors: Alexander I. Ershov, Richard M. Ness
  • Patent number: 7848369
    Abstract: A modulator drive circuit provides a modulator drive signal to modulate an optical signal for transport across a network infrastructure. The modulator drive circuit powered by an adjustable voltage source, such that the modulator drive signal is generated from a data signal and the adjustable voltage source, an AC component of the modulator drive signal being derived from the data signal while a DC component of the modulator drive signal being derived from the adjustable voltage source. An array of such modulator drive circuits are provided on a single substrate.
    Type: Grant
    Filed: December 23, 2008
    Date of Patent: December 7, 2010
    Assignee: Infinera Corporation
    Inventors: Jeffrey S. Bostak, Ting-Kuang Chiang, Michael Kauffman
  • Publication number: 20100290489
    Abstract: An EML assembly is provided that has and EAM and a DFB, with the DFB having an asymmetric ΒΌ wavelength phase shift positioned at a location that is in front of the center of the periodic structure of the DFB. In addition, the EML assembly has a tilted or bent waveguide that reduces reflections occurring at the front end facet, thereby enabling the EAM to produce a relatively high POUT level while also achieving reduced chirp and high single-mode yield in the DFB. By providing the EML assembly with a tilted or bent waveguide, the reflections at the front end facet are reduced without having to use an AR coating on the front end facet that has an extremely low reflectivity. By avoiding the need to use an AR coating on the front end facet that has an extremely low reflectivity, the AR coating that is used on the front end facet can be made using standard sputter deposition techniques to enable higher manufacturing yields to be achieved.
    Type: Application
    Filed: May 15, 2009
    Publication date: November 18, 2010
    Applicant: Avago Technologies Fiber IP (Singapore) Pte. Ltd.
    Inventors: Michele Agresti, Guido Alberto Roggero, Rui Yu Fang, Roberto Paoletti
  • Patent number: 7835408
    Abstract: An optical transmission system includes a laser, a transmitter and a receiver. The laser is capable of operating on an inhomogeneously broadened optical transition of the active region of the laser. A spectral bandwidth of an output lasing spectrum of the laser is greater than 5 nm and a spectral power density of the laser is greater than 2 mW/nm such that an optical power of the laser is greater than 10 mW. The laser provides a plurality of optical signals at different wavelengths. The transmitter is capable of providing modulation to each lasing wavelength independently and the receiver is capable of providing detection to each lasing wavelength independently.
    Type: Grant
    Filed: November 12, 2007
    Date of Patent: November 16, 2010
    Assignee: Innolume GmbH
    Inventors: Alexey Kovsh, Alexey Gubenko, Igor Krestnikov, Daniil Livshits, Sergey Mikhrin
  • Patent number: 7835409
    Abstract: An illumination light source is provided with a laser light source having a laser medium with a specified gain region, and a reflector having a narrow band reflection characteristic. A part of a laser light emitted from the laser light source is reflected and fed back by the reflector, so that an oscillation wavelength of the laser light source is fixed at a reflection wavelength. A peak of a gain region of the laser medium is shifted from the reflection wavelength by a change of an oscillation characteristic of the laser light source, so that the oscillation wavelength of the laser light source is changed from the reflection wavelength. Thus, an oscillation spectrum of the laser light source is spread to reduce speckle noise.
    Type: Grant
    Filed: February 22, 2007
    Date of Patent: November 16, 2010
    Assignee: Panasonic Corporation
    Inventors: Kiminori Mizuuchi, Kazuhisa Yamamoto
  • Publication number: 20100265420
    Abstract: An imaging system (200), such as a scanned laser projection system, includes one or more laser sources (201) configured to produce one or more light beams (204), and a light modulator (203) configured to produce images (206) from the light beams (204). Optional optical alignment devices (220) can be used to orient the light beams (204) into a combined light beam (205). A beam separator (221), which can be any of a birefringent wedge, compensated birefringent wedge, or a polymerized liquid crystal layer, is disposed between at least one of the laser sources (201) and the light modulator (203). The beam separator (221) is configured to receive light from the laser sources (201) and deliver two angularly separated and orthogonally polarized light beams (223) to the light modulator (203) so as to reduce speckle appearing when the images (206) are displayed on a display surface (207).
    Type: Application
    Filed: September 4, 2009
    Publication date: October 21, 2010
    Applicant: MICROVISION, INC.
    Inventors: Alban N. Lescure, Markus Duelli, Mark O. Freeman
  • Patent number: 7817686
    Abstract: Laser pulse shaping techniques produce tailored laser pulse spectral output. The laser pulses can be programmed to have desired pulse widths and pulse shapes (such as sub-nanosecond to 10 ns-20 ns pulse widths with 1 ns to several nanoseconds leading edge rise times). Preferred embodiments are implemented with one or more electro-optical modulators receiving drive signals that selectively change the amount of incident pulsed laser emission to form a tailored pulse output. Triggering the drive signal from the pulsed laser emission suppresses jitter associated with other stages of the link processing system and substantially removes jitter associated with pulsed laser emission build-up time.
    Type: Grant
    Filed: March 27, 2008
    Date of Patent: October 19, 2010
    Assignee: Electro Scientific Industries, Inc.
    Inventors: Xiaoyuan Peng, Brian W. Baird, William J. Jordens, David Martin Hemenway
  • Patent number: 7817682
    Abstract: A tunable pulsed laser source comprising a seed source adapted to generate a seed signal and an optical circulator. The optical circulator includes a first port coupled to the seed source, a second port, and a third port. The laser source also includes an amplitude modulator characterized by a first side and a second side. The first side is coupled to the second port of the optical circulator. The laser source further includes a first optical amplifier characterized by an input end and a reflective end including a spectral-domain reflectance filter. The input end is coupled to the second side of the amplitude modulator. Moreover, the laser source includes a second optical amplifier coupled to the third port of the optical circulator.
    Type: Grant
    Filed: October 15, 2008
    Date of Patent: October 19, 2010
    Assignee: PyroPhotonics Lasers Inc.
    Inventors: Richard Murison, Tullio Panarello, Benoit Reid, Reynald Boula-Picard, Pascal Deladurantaye, Robert Larose, Yves Taillon, Francois Brunet
  • Patent number: 7813389
    Abstract: A programmable laser pulse combines electrical modulation of the pulse frequency and optical modulation of the pulse shape to form laser pulses of prescribed pulse shapes. A prescribed pulse shape features high peak power and low average power. The laser system disclosed also allows for power-scaling and nonlinear conversions to other (shorter or longer) wavelengths. The system provides an economical reliable alternative to using a laser source with high repetition rates to achieve shaped pulses at a variety of wavelengths. The combinatorial scheme disclosed is inherently more efficient than existing subtractive methods.
    Type: Grant
    Filed: November 10, 2008
    Date of Patent: October 12, 2010
    Assignee: Electro Scientific Industries, Inc.
    Inventors: Xiaoyuan Peng, David Barsic, William J. Jordens, Qi Wang
  • Publication number: 20100254417
    Abstract: A method of controlling a frequency-converted laser source is provided where the laser source comprises a laser cavity, an external optical feedback component, a wavelength selective component, and a wavelength conversion device and the method comprises driving a gain section of the laser cavity with a gain signal that comprises a data component and a modulation component. The modulation component of the gain signal comprises a gain modulation amplitude IMOD that is sufficient to shift the available cavity modes in the spectral domain such that lasing at several different cavity modes sequentially is established as the gain signal is modulated.
    Type: Application
    Filed: April 7, 2009
    Publication date: October 7, 2010
    Inventors: Jacques Gollier, Dmitri Vladislavovich Kuksenkov
  • Publication number: 20100254418
    Abstract: [Problems] A laser beam irradiation apparatus which can accurately perform a linear welding with a uniform width on an irradiation portion even if the overlap ratio is lowered is provided. [Means for Solving the Problems] A laser beam irradiation apparatus includes laser beam generation means for emitting a laser beam, an optical fiber for transmitting the laser beam incident on an input side face to an output side face, an incident optical unit for introducing the laser beam emitted from the laser beam generation means to the input side face of the optical fiber, and an emission optical unit for applying the laser beam emitted from the output side face of the optical fiber to an irradiation portion, wherein the core cross section of the optical fiber is formed to be rectangular, preferably oblong, throughout the optical fiber or in a range at a predetermined distance from the output side face, and the length of the range where the core cross section is rectangular is preferably set to 3 m or above.
    Type: Application
    Filed: November 7, 2008
    Publication date: October 7, 2010
    Inventors: Takahiro Nagashima, Hideo Miura
  • Publication number: 20100254412
    Abstract: A method of controlling a frequency-converted laser source is provided where the laser source comprises a laser cavity, an external optical feedback component, a wavelength selective component, and a wavelength conversion device and the method comprises driving a phase section of the laser cavity with a phase control signal that comprises a modulation component having a modulation amplitude ?MOD that is sufficient to shift the available cavity modes in the spectral domain such that lasing at several different cavity modes sequentially is established as the phase control signal is modulated.
    Type: Application
    Filed: April 7, 2009
    Publication date: October 7, 2010
    Inventors: Jacques Gollier, Dmitri Vladislavovich Kuksenkov
  • Publication number: 20100246617
    Abstract: Narrow surface corrugated gratings for integrated optical components and their method of manufacture. An embodiment includes a grating having a width narrower than a width of the waveguide on which the grating is formed. In accordance with certain embodiments of the present invention, masked photolithography is employed to form narrowed gratings having a desired grating strength. In an embodiment, an optical cavity of a laser is formed with a reflector grating having a width narrower than a width of the waveguide. In another embodiment an integrated optical communication system includes one or more narrow surface corrugated gratings.
    Type: Application
    Filed: March 31, 2009
    Publication date: September 30, 2010
    Inventor: Richard Jones
  • Patent number: 7801189
    Abstract: Examples and implementations of photonic devices and techniques based on whispering gallery mode resonators formed of electro-optic materials to effectuate cross modulation between whispering gallery modes of different polarizations in the resonators.
    Type: Grant
    Filed: November 13, 2008
    Date of Patent: September 21, 2010
    Assignee: OEWaves, Inc.
    Inventors: Lutfollah Maleki, Andrey B. Matsko, Anatoliy Savchenkov, Vladimir Ilchenko
  • Publication number: 20100232461
    Abstract: The teachings presented herein disclose a method and apparatus for controlling the optical power of a laser in a passive optical network transmitter that outputs a modulated optical signal responsive to a modulated input signal. In one or more embodiments, such a control method comprises detecting the voltage of the modulated input signal, and setting the DC bias level of the laser as a function of the detected voltage. These teachings may be implemented, for example, by a laser control circuit in the transceiver module of an optical network unit (β€œONU”). Such an ONU may be advantageously used in a hybrid coaxial cable-optical fiber network, such as used in DPONs which interface cable system subscriber equipment to cable system head-end equipment.
    Type: Application
    Filed: March 12, 2009
    Publication date: September 16, 2010
    Applicant: EMCORE CORPORATION
    Inventor: Henry A. Blauvelt
  • Publication number: 20100232007
    Abstract: A system and method for providing a wavefront corrected high-energy beam of electromagnetic energy. In the illustrative embodiment, the system includes a source of a first beam of electromagnetic energy; an amplifier for amplifying said beam to provide a second beam; a sensor for sensing aberration in said second beam and providing an error signal in response thereto; a processor for processing said error signal and providing a correction signal in response thereto; and a spatial light modulator responsive to said correction signal for adjusting said beam to facilitate a correction of said aberration thereof. In more specific embodiments, the source is a laser and the sensor is a laser wavefront sensor. A mirror is disposed between said modulator and said sensor for sampling said beam. The mirror has an optical thin-film dielectric coating on at least one optical surface thereof. The coating is effective to sample said beam and transmit a low power sample thereof to said means for sensing aberration.
    Type: Application
    Filed: January 24, 2007
    Publication date: September 16, 2010
    Inventors: Robert W. Byren, William B. King, David M. Filgas
  • Patent number: 7796655
    Abstract: A tunable pulsed laser source includes a seed source adapted to generate a seed signal and an optical circulator having a first port coupled to the seed source, a second port, and a third port. The tunable pulsed laser source also includes a modulator driver adapted to produce a shaped electrical waveform and an amplitude modulator coupled to the modulator driver and adapted to receive the shaped electrical waveform. The amplitude modulator is characterized by a first side coupled to the second port of the optical circulator and a second side. The tunable pulsed laser source further includes a first optical amplifier characterized by an input end and a reflective end. The input end is coupled to the second side of the amplitude modulator. Moreover, the tunable pulsed laser source includes a second optical amplifier coupled to the third port of the optical circulator.
    Type: Grant
    Filed: September 12, 2008
    Date of Patent: September 14, 2010
    Assignee: PyroPhotonics Lasers Inc.
    Inventors: Richard Murison, Tullio Panarello, Benoit Reid, Reynald Boula-Picard
  • Patent number: 7792164
    Abstract: Systems and methods for pre-correcting accumulated optical nonlinear phase error in a shaped optical pulse derived from a continuous wave laser signal are provided. A continuous wave laser signal is received. A pulse signal is received. A shaped optical pulse is generated from the continuous wave laser signal upon being driven by the pulse signal. A pulse intensity level to be applied to the phase of the shaped optical pulse is received. A phase correcting signal is generated based on the pulse intensity level. Application of the phase correcting signal to the shaped optical pulse is time-synchronized and the phase correcting signal is applied to the shaped optical pulse to generate a pre-corrected shaped optical pulse.
    Type: Grant
    Filed: December 5, 2008
    Date of Patent: September 7, 2010
    Assignee: The Boeing Company
    Inventor: Monica L. Minden
  • Publication number: 20100220952
    Abstract: A power monitoring and correction to a desired power level of a laser or group of lasers utilizes two photodetectors which are employed to accurately determine the amount of output power from the front end or β€œcustomer” end of a laser or a plurality of such lasers. During power detection, which may be accomplished intermittently or continuously, the laser is modulated with a tone of low frequency modulation. One photodetector at the rear of the laser is employed to detect the DC value of the frequency tone, i.e., a value or number representative of the AC peak-to-peak swing, amplitude or modulation depth of the tone. Also, the rear photodetector may be employed to determine the optical modulation index (OMI). In either case, these values may be employed in a closed loop feedback system to adjust or otherwise calibrate the value of the low tone frequency relative to the total desired bias current applied to the laser.
    Type: Application
    Filed: April 12, 2010
    Publication date: September 2, 2010
    Inventors: Robert W. Smith, Alan C. Nilsson
  • Patent number: 7778548
    Abstract: A communication system has lighting equipment that has transmitter comprising multiple light-emitting elements that each emit light of different wavelengths and terminal equipment that has light-receiver comprising multiple light-receiving elements that receive optical signals for each of the different wavelengths.
    Type: Grant
    Filed: June 30, 2006
    Date of Patent: August 17, 2010
    Assignee: Avago Technologies General IP (Singapore) Pte. Ltd.
    Inventor: Kenji Yamamoto
  • Patent number: 7773643
    Abstract: A laser light generating apparatus includes a laser light source, a phase-modulator, a signal generating unit configured to generate a modulation signal applied to the phase-modulator, a first external resonator, a second external resonator disposed at the stage succeeding the first external resonator, nonlinear optical elements each provided in the external resonators configured to implement wavelength conversion, an optical path length varying unit for varying the optical path length of each of the external resonators, and a control circuit having a negative feedback arrangement configured to obtain error signals for each of the external resonators, and configured to control the optical path length varying unit using the error signals according to FM sideband method. In the laser light generating apparatus, the external resonators are each held simultaneously in a resonance state by setting the frequency of the modulation signal and by controlling the optical path length of each of the external resonators.
    Type: Grant
    Filed: February 5, 2008
    Date of Patent: August 10, 2010
    Assignee: Sony Corporation
    Inventor: Hisashi Masuda
  • Patent number: 7772615
    Abstract: Semiconductor electrooptic medium shows behavior different from a medium based on quantum confined Stark Effect. A preferred embodiment has a type-II heterojunction, selected such, that, in zero electric field, an electron and a hole are localized on the opposite sides of the heterojunction having a negligible or very small overlap of the wave functions, and correspondingly, a zero or a very small exciton oscillator strength. Applying an electric field results in squeezing of the wave functions to the heterojunction which strongly increases the overlap of the electron and the hole wave functions, resulting in a strong increase of the exciton oscillator strength. Another embodiment of the novel electrooptic medium includes a heterojunction between a layer and a superlattice, wherein an electron and a hole in the zero electric field are localized on the opposite sides of the heterojunction, the latter being effectively a type-II heterojunction.
    Type: Grant
    Filed: August 7, 2008
    Date of Patent: August 10, 2010
    Assignee: Connector Optics
    Inventors: Nikolai Ledentsov, Vitaly Shchukin
  • Patent number: 7760782
    Abstract: The invention aims at realizing a 1300-nm-band direct modulation laser, having a single lateral mode, in which a chip light power of several milliwatts and a low current operation are simultaneously realized. Also, the invention aims at realizing a laser light source excellent in economy as well by realizing output characteristics of a vertical cavity surface light emitting laser. A distributed Bragg reflector laser is constructed in the form of a semiconductor laser having a multilayer structure formed on a predetermined semiconductor substrate. The multilayer structure includes an active region for emitting a laser beam, and a distributed Bragg reflector layer. A length of the active region falls within the range of 10 to 100 ?m, and a laser light beam is generated in accordance with ON/OFF of current injection to the active region.
    Type: Grant
    Filed: June 23, 2006
    Date of Patent: July 20, 2010
    Assignee: Opnext Japan, Inc.
    Inventor: Masahiro Aoki
  • Patent number: 7756169
    Abstract: A high-power laser system includes a laser master oscillator, a plurality of fiber laser amplifiers producing intermediate output beamlets, a combiner for combining the intermediate beamlets into a combined output beam, and a piston error controller for minimizing errors related to beam combination that may degrade the quality of the combined output beam. A piston error controller processes a sample of the combined output beam using a Diffractive Optical Element to isolate a signal representing the total piston error of the combined beam. The controller uses amplitude modulation based on Hadamard code words to tag each non-reference intermediate beamlet with a unique code sequence orthogonal to those used for the other beamlets. For each intermediate beamlet, the associated piston error contribution is recovered using a Hadamard decoder. A very small phase dither is also introduced to allow the sign or direction of the piston error to be recovered.
    Type: Grant
    Filed: January 23, 2008
    Date of Patent: July 13, 2010
    Assignee: Northrop Grumman Systems Corporation
    Inventors: Peter M. Livingston, Robert R. Rice
  • Patent number: 7747174
    Abstract: Multi-channel Fabry-Perot laser transmitters and methods of generating multiple modulated optical signals are described. In one aspect, an optical transmitter includes a Fabry-Perot (FP) laser, an optical isolator, an optical splitter, and multiple electroabsorption modulators (EAMs). The FP laser is operable to generate multimode laser light. The optical isolator is arranged to transmit the multimode laser light. The optical splitter has more than one optical output and an optical input that is arranged to receive the multimode laser light transmitted by the optical isolator. Each of the EAMs is operable to modulate a respective laser light output from a respective optical output of the optical splitter. In another aspect, multimode laser light is generated. The multimode laser light is directionally isolated. The directionally-isolated multimode laser light is divided into more than one divided laser light output.
    Type: Grant
    Filed: September 8, 2004
    Date of Patent: June 29, 2010
    Assignee: Avago Technologies Fiber IP (Singapore) Pte. Ltd.
    Inventor: Tirumala R. Ranganath
  • Patent number: 7746909
    Abstract: The present invention provides a compact, low cost integrated continuous wave (CW) laser/electro-absorption (EA) modulator solution that supports the non-return to zero (NRZ) modulation format for long-haul optical transmission that results in high output extinction ratio of an integrated EA modulated laser (EML) and low modulator chirp. The methods and systems of the present invention treat the laser and EA modulator sections of the EML as separate components. An information signal is connected to two separate drivers: a laser driver that drives the laser section and a modulator driver that drives the EA modulator section.
    Type: Grant
    Filed: November 30, 2006
    Date of Patent: June 29, 2010
    Assignee: Ciena Corporation
    Inventor: Michael Haidar Shahine
  • Patent number: 7742511
    Abstract: A laser system for processing a workpiece includes a tunable pulsed laser source having an output comprising a set of optical pulses. The tunable pulsed laser source includes a seed source, an optical circulator having a first port coupled to the seed source, a second port, and a third port, a modulator driver, and an amplitude modulator coupled to the modulator driver. The tunable pulsed laser source also includes a first optical amplifier characterized by an input end and a reflective end and a second optical amplifier coupled to the third port of the optical circulator. The laser system also includes a controller configured to adjust laser parameters of the tunable pulsed laser source, a supporting member configured to support the workpiece, and an optical system configured to adjust laser beams from the tunable pulsed laser source and direct them towards the workpiece.
    Type: Grant
    Filed: September 12, 2008
    Date of Patent: June 22, 2010
    Assignee: PyroPhotonics Lasers Inc.
    Inventors: Richard Murison, Tullio Panarello, Benoit Reid, Reynald Boula-Picard
  • Publication number: 20100150188
    Abstract: A spectrum-sliced seed light module for a wavelength division multiplexing passive optical network (WDM PON) is provided. The seed light module includes an optical amplifier to amplify seed light, an optical wavelength filter to transmit broadband light, which is output in opposite direction to an output direction of the seed light, at periodic frequency intervals, and a reflective mirror to reflect light which is spectrum-sliced through the optical wavelength filter to the optical wavelength filter.
    Type: Application
    Filed: September 3, 2009
    Publication date: June 17, 2010
    Inventors: Han-hyub Lee, Byoung-whi Kim, Jea-hoon Yu, Mahn Yong Park, Jai-sang Koh
  • Patent number: 7738795
    Abstract: An example of an optical source includes a VCSEL and a filter. The filter is positioned on the VCSEL and is configured and arranged such that an input to the filter from the VCSEL comprises a directly modulated optical data signal, and a corresponding output of the filter comprises an amplitude and/or phase modulated optical data signal, optimized for long-distance transmission in the optical fiber.
    Type: Grant
    Filed: March 2, 2006
    Date of Patent: June 15, 2010
    Assignee: Finisar Corporation
    Inventors: Hongyu Deng, Yuri V Vandyshev
  • Publication number: 20100142571
    Abstract: Provided is a multiple distributed feedback laser device. The laser device includes an active layer, a first diffraction grating, and a second diffraction grating. The substrate includes a first distributed feedback region, a modulation region, and a second distributed feedback region. The first diffraction grating is coupled to the active layer in the first distributed feedback region. The second diffraction grating is coupled to the active layer in the second distributed feedback region. In addition, the laser device includes a first micro heater and a second micro heater. The first micro heater supplies heat to the first diffraction grating. The second micro heater supplies heat to the second diffraction grating. The first micro heater and the second micro heater are controlled independently from each other.
    Type: Application
    Filed: July 20, 2009
    Publication date: June 10, 2010
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Kyung Hyun PARK, Jaeheon Shin, Namje Kim, Chul-Wook Lee, Eundeok Sim, Sang-Pil Han, Yongsoon Baek
  • Patent number: 7734189
    Abstract: An optical transmitter includes a drive laser, a 1Γ—N splitter, and an array of modulators. The 1Γ—N splitter is coupled to split a beam from the drive laser into separated beams, and the modulators modulate the respective beam to represent respective data signals that are transmitted in parallel. Embodiments of the transmitter can provide high data rate communications at low cost by eliminating the need for an array of isolators and eliminating the need for high quality AR coatings. Additionally, an integrated optical circuit containing the modulator array does not require an array of lasers and can be fabricated at higher yields and lower costs.
    Type: Grant
    Filed: November 30, 2006
    Date of Patent: June 8, 2010
    Assignee: Avago Technologies Fiber IP (Singapore) Pte. Ltd.
    Inventor: Tirumala R. Ranganath
  • Patent number: 7724789
    Abstract: According to methods and apparatus described herein, multimode laser source capable of emitting a diffraction-limited beam of various shapes (including single-lobe shape) can be realized. An optical apparatus for generating a such diffraction-limited beam comprises a spatial phase modulator for spatially modulating a spectrally dispersed optical signal emitted from a semiconductor laser into a combined-mode optical signal, wherein the lateral modes of the optical signal from the laser are combined into a diffraction-limited beam. Also, a coupling optical system is provided for wavelength-demultiplexing the multimode optical signal before the multimode optical signal is spatially modulated by the spatial phase modulator, and also for wavelength-multiplexing the combined-mode optical signal.
    Type: Grant
    Filed: May 2, 2007
    Date of Patent: May 25, 2010
    Assignee: Board of Regents, The University of Texas System
    Inventor: Nikolai M. Stelmakh
  • Publication number: 20100110535
    Abstract: A laser amplifier includes a pump source and an optically active fiber having an input portion configured to receive a signal source and an output portion. The pump source is optically coupled to the optically active fiber. The laser amplifier also includes an output fiber optically coupled to the output portion of the optically active fiber. The output fiber includes a rare-earth element. The laser amplifier further includes a beam expansion section joined to the output fiber.
    Type: Application
    Filed: October 31, 2008
    Publication date: May 6, 2010
    Applicant: PyroPhotonics Lasers Inc.
    Inventors: Richard Murison, Tullio Panarello
  • Publication number: 20100103088
    Abstract: A solid-state laser apparatus includes: a semiconductor laser light source for emitting laser light; an optical resonator having a solid-state laser medium to be excited by incidence of the laser light to oscillate fundamental laser light, and a mirror; and a quasi phase matching wavelength converting element, disposed in the optical resonator, for converting a wavelength of the fundamental laser light, wherein the quasi phase matching wavelength converting element is formed with a polarization inversion region having a predetermined cycle, and the length of the polarization inversion region in an optical axis direction is 1.0 mm or less.
    Type: Application
    Filed: January 18, 2008
    Publication date: April 29, 2010
    Inventors: Toshifumi Yokoyama, Kazuhisa Yamamoto, Hiroyuki Furuya, Kiminori Mizuuchi
  • Patent number: 7706056
    Abstract: A method of modulation terahertz radiation comprising: (A) generating Terahertz radiation by pumping nonequilibrium electrons into a Magnon Gain Medium (MGM), wherein propagation of nonequilibrium electrons in the MGM causes generation of nonequilibrium magnons, and wherein interaction between the nonequilibrium magnons causes generation of the Terahertz radiation; and (B) frequency modulating THz radiation generated in the MGM by applying longitudinal AC magnetic field, or by applying AC electrical field bias.
    Type: Grant
    Filed: August 9, 2007
    Date of Patent: April 27, 2010
    Assignee: Terahertz Technologies LLC
    Inventors: Yehiel Korenblit, Boris G. Tankhilevich
  • Publication number: 20100097614
    Abstract: An optical coherence tomography device includes a wavelength scanning laser light source (10) provided with two Fabry-Perot resonators (13A, 13B) provided in a light path for laser oscillation. The values of FSR (free spectral range) of the Fabry-Perot resonators are set so as to be proximate to each other. The resonator length of at least one of the two Fabry-Perot resonators is periodically varied within a preset range to cause the two Fabry-Perot resonators (13A, 13B) to operate as a wavelength length varying filter of a narrow pass band capable of varying the selection wavelength by the vernier effect to output laser light that has wavelength temporally scanned.
    Type: Application
    Filed: September 3, 2007
    Publication date: April 22, 2010
    Applicant: OPTICAL COMB, INC.
    Inventors: Motonobu Kourogi, Kazuhiro Imai
  • Publication number: 20100091805
    Abstract: An optical semiconductor device includes an optical semiconductor element, a metal pattern and at least one thermal conductive material. The optical semiconductor element has a first optical waveguide region and a second optical waveguide region. The second optical waveguide region is optically coupled to the first optical waveguide region and has a heater for changing a refractive index of the second optical waveguide region. The metal pattern is provided on an area to be thermally coupled to a temperature control device. The thermal conductive material couples the metal pattern with an upper face of the first optical waveguide region of the optical semiconductor element. The thermal conductive material is electrically separated from the first optical waveguide region.
    Type: Application
    Filed: December 17, 2009
    Publication date: April 15, 2010
    Applicant: EUDYNA DEVICES INC.
    Inventors: Tsutomu Ishikawa, Takuya Fujii
  • Patent number: 7697578
    Abstract: The present invention provides a directly modulatable wavelength variable laser that enables long distance and large volume communication with a simple and compact configuration. The wavelength variable laser includes a semiconductor optical amplifier, an optical filter, and a frequency-amplitude converter. The semiconductor optical amplifier produces optical gain of the light signal. The optical filter configured by multi-stage connected waveguide ring resonators performs frequency modulation on the light signal. The frequency-amplitude converter performs amplitude modulation on the light signal frequency modulated in the optical filter.
    Type: Grant
    Filed: August 29, 2007
    Date of Patent: April 13, 2010
    Assignee: NEC Corporation
    Inventor: Hiroyuki Yamazaki
  • Publication number: 20100080253
    Abstract: An imaging system (200) includes a plurality of laser sources (201) configured to produce a plurality of light beams (204). One or more optical alignment devices (220) orient the light beams (204) into a collimated light beam (205). A light modulator (203) modulates the collimated light beam (205) such that images (206) can be presented on a display surface (207). Speckle is reduced with an optical feedback device (221) that causes the laser sources (201) to operate in a coherence collapsed state. Examples of optical feedback devices (221) include partially reflective mirrors and beam splitter-mirror combinations.
    Type: Application
    Filed: September 30, 2008
    Publication date: April 1, 2010
    Applicant: MICROVISION, INC.
    Inventor: Taha Masood
  • Publication number: 20100074619
    Abstract: A method comprises: receiving a RF signal; providing a RF signal level; varying a laser power DC set point linearly with the RF signal level over a selected range; and modulating with the RF signal laser output power about the DC set point. The RF signal level can be RF signal amplitude or RF signal power. An apparatus comprises: a laser; a RF detector adapted to receive the RF signal and to provide the RF signal level; a laser power control circuit coupled to the RF detector and to the laser and adapted to vary the laser power DC set point substantially linearly with respect to the RF signal level over a selected range; and a laser modulator coupled to the laser and adapted to receive the RF signal and to modulate therewith laser output power about the DC set point.
    Type: Application
    Filed: November 22, 2006
    Publication date: March 25, 2010
    Inventor: Henry A. Blauvelt
  • Publication number: 20100067555
    Abstract: A method and apparatus for providing optical supercontinuum. The method comprises creating a spectrally narrow phase feature within a supercontinuum spectrum produced from a laser pulse that has been subjected to supercontinuum generation, thereby producing a modified supercontinuum spectrum, and propagating the modified supercontinuum spectrum through an optical waveguide that is suitable for supercontinuum generation, thereby further modifying the modified supercontinuum spectrum. The method may include modifying the modified supercontinuum spectrum by increasing its energy in a vicinity of the phase feature.
    Type: Application
    Filed: July 5, 2007
    Publication date: March 18, 2010
    Applicant: The University of Sydney
    Inventors: Dane Austin, Benjamin John Eggleton, Carel Martijn De Sterke, Paul Steinvurzel, Jeremy Bolger, Thomas Brown, Feng Luan, Dong-II Yeom
  • Patent number: 7680364
    Abstract: A transmissive active channel element is provided in each signal channel of a monolithic multi-channel TxPIC where each channel also includes a modulated source. The active channel element functions both as a power control element for both monitoring and regulating the output channel signal level of each signal channel and as a modulator for channel wavelength tagging or labeling to provide for wavelength locking the modulated sources. The power regulating function is also employed to control the channel signal power outputs of each channel to be uniform across the channel signal array. All of these functions are carried out by a feedback loop utilizing digital signal processing.
    Type: Grant
    Filed: June 29, 2006
    Date of Patent: March 16, 2010
    Assignee: Infinera Corporation
    Inventors: Alan C. Nilsson, Robert W. Smith, Yishai Kagan, Paul N. Freeman
  • Patent number: 7680368
    Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.
    Type: Grant
    Filed: July 6, 2007
    Date of Patent: March 16, 2010
    Assignee: Infinera Corporation
    Inventors: David F. Welch, Vincent G. Dominic, Fred A. Kish, Jr., Mark J. Missey, Radhakrishnan L. Nagarajan, Atul Mathur, Frank H. Peters, Robert B. Taylor, Matthew L. Mitchell, Alan C. Nilsson, Stephen G. Grubb, Richard P. Schneider, Charles H. Joyner, Jonas Webjorn, Drew D. Perkins