Phase Modulation Type Patents (Class 385/3)
  • Publication number: 20100100006
    Abstract: The present invention relates to an apparatus for producing optical pulses of a desired wavelength. The apparatus includes an optical pulse source operable to generate input optical pulses at a first wavelength. The apparatus further includes a higher order mode (HOM) fiber module operable to receive the input optical pulses at the first wavelength, and thereafter to produce output optical pulses at the desired wavelength by soliton self-frequency shift (SSFS). The present invention also relates to a method of producing optical pulses having a desired wavelength. This method includes generating input optical pulses using an optical pulse source, where the input optical pulses have a first wavelength and a first spatial mode.
    Type: Application
    Filed: October 26, 2007
    Publication date: April 22, 2010
    Applicant: CORNELL RESEARCH FOUNDATION, INC
    Inventors: Chris Xu, James Van Howe
  • Patent number: 7693356
    Abstract: An optical modulator comprises a Z-cut lithium niobate substrate on which is formed a Mach-Zehnder interferometer having two generally parallel waveguides lying beneath a buffer layer of dielectric material. First and second ground electrodes and a hot electrode are disposed on the buffer layer, the first and second ground electrodes being spaced either side of the hot electrode, the hot electrode and the first ground electrode being proximate to at least apart of the respective waveguides. The electrode structure is unsymmetrical in that (a) the hot electrode and the first ground electrode each have a width substantially less than that of the second ground electrode and or (b) the spacing between the first ground and hot electrodes is different from the spacing between the second ground and hot electrodes. whereby a range of chirp values can be obtained.
    Type: Grant
    Filed: September 11, 2008
    Date of Patent: April 6, 2010
    Assignee: Oclaro (North America), Inc.
    Inventors: Giovanni Gilardi, Paolo Milanese, Simone Pensa
  • Publication number: 20100079848
    Abstract: Speckle effect in display system is reduced by utilizing the instability of phase-coherent light and the transmission of the instable phase-coherent light through a multi-mode optical fiber with a suitable length.
    Type: Application
    Filed: September 30, 2008
    Publication date: April 1, 2010
    Applicant: Texas Instruments Incorporated
    Inventors: Regis Grasser, Hongqin Shi, Terry A. Bartlett
  • Patent number: 7689067
    Abstract: A nested modulator is provided where the circuit arrangement of modifying electrodes including signal electrodes is simplified, and at the same time, the drive voltage can be lowered.
    Type: Grant
    Filed: November 7, 2007
    Date of Patent: March 30, 2010
    Assignees: Sumitomo Osaka Cement Co., Ltd., National Institute for Materials Science, National Institute of Information and Communications Technology
    Inventors: Junichiro Ichikawa, Kaoru Higuma, Futoshi Yamamoto, Satoshi Oikawa, Shingo Mori, Sunao Kurimura, Kenji Kitamura, Tetsuya Kawanishi, Masahiro Tsuchiya, Masayuki Izutsu
  • Patent number: 7689066
    Abstract: An optical modulator is provided for modulating light propagating in a three-dimensional optical waveguide 5 by applying a voltage thereto. The optical modulator has the three-dimensional optical waveguide 5 including at least one pair of branch optical waveguides 5c and 5d, a multiplexing part 5e of the branch optical waveguides and an emission part 5f provided in the downstream of the multiplexing part, modulation electrodes 3A, 3B and 4 for applying a signal voltage for modulating light propagating in the three-dimensional optical waveguide 5, and guiding waveguides 6A and 6B for guiding primary mode light from the multiplexing part. Thickness of the substrate is 20 ?m or less at least under the modulation electrodes, and an operation point of the optical modulator is controlled by changing, based on light output from the guiding waveguides, DC bias applied onto the modulation electrodes.
    Type: Grant
    Filed: August 20, 2007
    Date of Patent: March 30, 2010
    Assignee: NGK Insulators, Ltd.
    Inventors: Jungo Kondo, Osamu Mitomi, Kenji Aoki, Yuichi Iwata, Tetsuya Ejiri
  • Publication number: 20100074570
    Abstract: According to an aspect of an embodiment, an optical circuit comprising: at least two pairs of two input waveguides; a slab waveguide with one end coupled to two pairs or more of the two input waveguides; and four output waveguides coupled to another end of the slab waveguide; wherein a distance between two pairs of adjacent two input waveguides among two pairs or more of the two input waveguides is approximately four times as long as a distance between the two input waveguides.
    Type: Application
    Filed: February 24, 2009
    Publication date: March 25, 2010
    Applicant: FUJITSU LIMITED
    Inventor: Koji Terada
  • Patent number: 7684666
    Abstract: The present invention is a method and an apparatus for tuning an optical delay line. In one embodiment, an optical delay line includes at least one ring resonator in which light is guided or is confined and at least one heater positioned laterally from the ring resonator. The heater produces heat in a localized area, allowing for the tuning of individual delay elements with minimal crosstalk.
    Type: Grant
    Filed: November 10, 2006
    Date of Patent: March 23, 2010
    Assignee: International Business Machines Corporation
    Inventors: Hendrik Hamann, Yurii A. Vlasov, Fengnian Xia
  • Patent number: 7684655
    Abstract: An electro-optic device includes a semiconducting layer in which is formed a waveguide, a modulator formed across the waveguide comprising a p-doped region to one side and an n-doped region to the other side of the waveguide, wherein at least one of the doped regions extends from the base of a recess formed in the semiconducting layer. In this way, the doped regions can extend further into the semiconducting layer and further hinder escape of charge carriers without the need to increase the diffusion distance of the dopant and incur an additional thermal burden on the device. In an SOI device, the doped region can extend to the insulating layer. Ideally, both the p and n-doped regions extend from the base of a recess, but this may be unnecessary in some designs. Insulating layers can be used to ensure that dopant extends from the base of the recess only, giving a more clearly defined doped region.
    Type: Grant
    Filed: February 22, 2002
    Date of Patent: March 23, 2010
    Assignee: Kotura, Inc.
    Inventors: Adrian Petru Vonsovici, Ian Edward Day
  • Publication number: 20100067841
    Abstract: The optical device includes an outer Mach-Zehnder interferometer having two outer arm waveguides; and two multilevel modulators, each formed on one of the outer arm waveguides, which perform multilevel modulation on input light independently of each other, one of the multilevel modulators including an inner Mach-Zehnder interferometer having two inner arm waveguides, and two signal electrodes which provide electric fields that are to interact with light propagates through the inner Mach-Zehnder interferometer, the inner Mach-Zehnder interferometer or the signal electrodes cross an even number of times at crossing points so as to alternately interact with the electric fields provided by the signal electrodes, a part of a light propagation region of the inner arm waveguides which region has a boundary defined by at least one of the crossing points forms a polarization inversion region. The optical transmitter includes the above optical device.
    Type: Application
    Filed: June 18, 2009
    Publication date: March 18, 2010
    Applicant: Fujitsu Limited
    Inventors: Masaki SUGIYAMA, Kazuhiro TANAKA
  • Patent number: 7676120
    Abstract: A phase shift device of an optical fiber signal includes an actuator for changing the signal phase in at least one fiber portion by inducing the phase change by thermo-optical effect. An antenna system incorporating phase shift devices using the thermo-optical effect find particular utility in automotive and telecommunications fields.
    Type: Grant
    Filed: February 17, 2009
    Date of Patent: March 9, 2010
    Assignee: STMicroelectronics s.r.l.
    Inventors: Guido Chiaretti, Antonio Fincato
  • Publication number: 20100054654
    Abstract: Herein disclosed is an optical modulation device, comprising: a substrate 1 having a polarization non-reversal region 17a and a polarization reversal region 17b; an optical waveguide 18 including first and second branched optical waveguide portions 18a, 18b; and a traveling waveguide including a center electrode 19a and a ground electrode 19b, 19c to have an electric signal applied thereto, said traveling waveguide and said first and second branched optical waveguide portions collectively forming an interaction portion to have said incident light interacted with said electric signal, said interaction portion being constituted by a first interaction sub-portion 20a and a second interaction sub-portion 20b, said first and second interaction sub-portions being respectively positioned in regions of said substrate having opposite polarization orientations with each other, in which said center electrode is positioned in face to face relationship with one of said first and second branched optical waveguide portions
    Type: Application
    Filed: February 16, 2006
    Publication date: March 4, 2010
    Applicant: Anritsu Corporation
    Inventors: Kenji Kawano, Masaya Nanami, Hiroaki Senda, Takeshi Hondo, Seiji Uchida, Yuji Sato, Toru Nakahira
  • Patent number: 7668409
    Abstract: An optical communication device includes a substrate which has electro-optical effect; a first optical modulator which has a pair of waveguides formed in the substrate; a second optical modulator which has a pair of waveguides formed in the substrate; a waveguide coupler which is provided in an output of the first optical modulator, the waveguide coupler being able to couple and branch light propagating through the pair of waveguides of the first optical modulator; and a delay connecting section which gives differential delay to the output branched by the waveguide coupler and inputs the output to the pair of waveguide of the second optical modulator. As a result, the optical communication device and optical device in which insertion loss is reduced compared with the conventional optical modulator can be provided.
    Type: Grant
    Filed: September 13, 2007
    Date of Patent: February 23, 2010
    Assignee: Fujitsu Limited
    Inventor: Masaki Sugiyama
  • Publication number: 20100040322
    Abstract: An electro-optic polymer semiconductor integrated circuit includes one or more doped regions configured to drive one or more electrodes, and the electrodes are configured to drive a juxtaposed electro-optic core. The assembly may include a planarization layer disposed at least partially coplanar with the electrodes. The circuit may include an integrated multiplexer, driver configured to receive a signal from the multiplexer, at least one high speed electrode configured to be driven by the driver and modulate light energy passed through a hyperpolarizable poled chromophore regions disposed near the high speed electrode. The circuit may include a calibration storage circuit. The circuit may include, during fabrication, structures to provide voltage to a buried electrode and a shield to prevent damage from the poling field.
    Type: Application
    Filed: October 7, 2008
    Publication date: February 18, 2010
    Applicant: LUMERA CORPORATION
    Inventors: Bing Li, Raluca Dinu, Eric Miller, Danliang Jin, Hui Chen, Christopher A. Wiklof
  • Patent number: 7660491
    Abstract: A cw-laser source transmits low-noise, narrow-linewidth optical power via an optical fiber to a bias-free electro-optic phase modulator at a remote site, where an antenna or an RF sensor is located. The RF electrical signal modulates the phase modulator at the remote site, converting an electrical signal into an optical signal. The phase-modulated optical signal is fed back via the optical fiber to an optical filter whose filter transfer characteristics can be tuned and reconfigured to cancel the intermodulation distortion terms, particularly the dominant 3rd order intermodulation, as well as the 2nd order. The filtered optical signal is converted to the RF signal at the photodetector. The optical filter is used to effectively “linearize” the signal at the receiver end, rather than at the modulator end.
    Type: Grant
    Filed: August 1, 2007
    Date of Patent: February 9, 2010
    Assignee: EOSpace, Inc.
    Inventor: Suwat Thaniyavarn
  • Patent number: 7660027
    Abstract: An optical modulator comprises an electrode 21 which applies to an optical waveguides 12 of a Mach-Zehnder type optical interference system a first electric signal based on an alternating current signal S1 and a direct current bias V1, an electrode 22 which applies to an optical waveguide 13 of the Mach-Zehnder type optical interference system a second electric signal based on an alternating current signal S2 and a direct current bias V2, and a bias setting section 41 which sets average direct current levels of the first and second electric signals based on signal frequency information D1 which indicates a magnitude relation between a maximum frequency of the alternating current signal S1 and a maximum frequency of the alternating current signal S2.
    Type: Grant
    Filed: November 6, 2007
    Date of Patent: February 9, 2010
    Assignee: Panasonic Corporation
    Inventors: Tsutomu Niiho, Kouichi Masuda, Masaru Fuse, Fumio Fujisaki, Kuniharu Itakura, Tomoaki Ohira
  • Publication number: 20100027936
    Abstract: A tuneable electro-optic modulator (1) comprising first and second spaced apart output optical waveguides (2, 3), each output optical waveguide comprising a coupled portion (12) optically coupled to a corresponding coupled portion (13) of the other output optical waveguide, the coupled portions defining a coupling region (14) therebetween; an optical source adapted to symmetrically provide an optical signal to the first and second output optical waveguides; a portion of each of the output optical waveguides having a signal electrode (6, 7) thereon; the modulator further comprising a central optical waveguide (15), at least a portion of which is arranged in the coupling region, the central optical waveguide having a tuning electrode (16) thereon.
    Type: Application
    Filed: June 14, 2007
    Publication date: February 4, 2010
    Inventor: John Heaton
  • Patent number: 7657146
    Abstract: An optoelectronic controller for regulating an optical signal. The controller includes a ridge or rib waveguide in an SOI-type substrate. The controller also includes an active zone formed by a plurality of thin layers of silicon. The layers are either N+ type doped or P+ type doped. The zone is defined between an N+ doped zone and a P+ doped zone which together form a PIN diode. The optoelectronic controller is all-silicon and operates by carrier desertion.
    Type: Grant
    Filed: March 29, 2005
    Date of Patent: February 2, 2010
    Assignees: Universite Paris-SUD, Centre National de la Recherche Scientifique - CNRS
    Inventors: Suzanne Laval, Delphine Marris, Éric Cassan, Daniel Pascal
  • Patent number: 7657130
    Abstract: A silicon-insulator-silicon capacitive (SISCAP) optical modulator is configured to provide analog operation for applications which previously required the use of relatively large, power-consuming and expensive lithium niobate devices. An MZI-based SISCAP modulator (preferably a balanced arrangement with a SISCAP device on each arm) is responsive to an incoming high frequency electrical signal and is biased in a region where the capacitance of the device is essentially constant and the transform function of the MZI is linear.
    Type: Grant
    Filed: October 8, 2008
    Date of Patent: February 2, 2010
    Assignee: Lightwire, Inc.
    Inventors: Kalpendu Shastri, Prakash Gothoskar, Vipulkumar Patel, David Piede, Mark Webster
  • Patent number: 7653267
    Abstract: A beam modulator (14) for modulating a beam (20) includes a modulator element (26) and a housing assembly (24). The modulator element (26) is positioned in the path of the beam (20). The housing assembly (24) retains the modulator element (26). Additionally, the housing assembly (24) defines a resonant cavity (328) with the modulator element (26) positioned therein. The housing assembly (24) includes a size adjuster (30) that can be moved to selectively adjust the size of the resonant cavity (328). As a result thereof, in certain embodiments, the resonant frequency of the beam modulator (14) can be easily tuned over a relatively large frequency range.
    Type: Grant
    Filed: May 9, 2007
    Date of Patent: January 26, 2010
    Assignee: Newport Corporation
    Inventor: Xin Luo
  • Publication number: 20100014801
    Abstract: In a multilevel light intensity modulator of the invention, input light is branched into n (n is an integer of 2 or more), and respectively sent to n branching waveguides. On the branching waveguides are respectively provided MZI light modulating sections. The MZI light modulating sections branch the input light into two at a branching ratio different from 0.5:0.5, and respectively output a binary optical signal with a quenching ratio being deteriorated, by on/off driving with a binary electric signal. Then by coupling the light output from the MZI light modulating sections, an optical signal with the light intensity modulated to a 2n value not including the zero level is output. As a result quaternary or higher level light intensity modulation which does not include the zero level, can be realized by a practical configuration using a binary electric signal.
    Type: Application
    Filed: September 18, 2009
    Publication date: January 21, 2010
    Applicant: FUJITSU LIMITED
    Inventor: Masaharu Doi
  • Patent number: 7643708
    Abstract: Herein disclosed is an optical modulator, comprising: a substrate (1) having an electro-optic effect; an optical waveguide (3) formed in the substrate; a traveling wave electrode (4) including a center electrode (4a) and ground electrodes (4b, 4c) to have a high frequency electric signal applied thereto, the traveling wave electrode and the optical waveguide collectively forming a high frequency interaction portion (20) to have the incident light phase modulated under the condition that the high frequency electric signal is applied to the traveling wave electrode; and bias electrodes each including a center electrode (22a, 23a) and ground electrodes (22b, 22c, 23b, 23c) to have a bias voltage applied thereto, each of the bias electrodes and the optical waveguide collectively forming a bias voltage interaction portion (19, 21) to have the incident light phase modulated under the condition that the bias voltage is applied to the bias electrode, in which the traveling wave electrode and the bias electrodes are e
    Type: Grant
    Filed: July 5, 2006
    Date of Patent: January 5, 2010
    Assignee: Anritsu Corporation
    Inventors: Kenji Kawano, Masaya Nanami, Yuji Sato, Seiji Uchida, Nobuhiro Igarashi, Toru Nakahira, Hiroaki Senda
  • Patent number: 7643714
    Abstract: Systems and methods for manipulating light with high index contrast waveguides clad with substances having that exhibit large nonlinear electro-optic constants ?2 and ?3. Waveguides fabricated on SOI wafers and clad with electro-optic polymers are described. Embodiments of waveguides having slots, electrical contacts, and input waveguide couplers are discussed. Waveguides having closed loop structures (such as rings and ovals) as well as linear or serpentine waveguides, are described. Optical signal processing methods, such as optical rectification and optical modulation, are disclosed. Designs having responsivity of less than 1 volt-centimeter are described.
    Type: Grant
    Filed: May 8, 2008
    Date of Patent: January 5, 2010
    Assignee: California Institute of Technology
    Inventors: Michael J. Hochberg, Tom Baehr-Jones, Axel Scherer
  • Patent number: 7641400
    Abstract: A package design for electro-optic devices has been developed in which the substrate supporting the electro-optic element serves also as the base of the device housing. The electro-optic element is flip-chip bonded to the substrate. In a preferred embodiment the substrate is a multi-level wiring board.
    Type: Grant
    Filed: April 29, 2008
    Date of Patent: January 5, 2010
    Assignee: Oclaro Inc.
    Inventors: Roberto Galeotti, Luigi Gobbi, Mario Bonazzoli
  • Publication number: 20090323164
    Abstract: An optical modulation device includes: an optical splitter for splitting input light into a first input beam and a second input beam; an optical intensity modulator for modulating the intensity of the first input beam in response to a modulating signal; a variable optical phase shifter for shifting the phase of the second input beam; and an optical combiner for combining an output beam of the optical intensity modulator and an output beam of the variable optical phase shifter into a combined beam and outputting the combined beam. The amount of phase shift produced by the variable optical phase shifter is externally controlled.
    Type: Application
    Filed: October 17, 2008
    Publication date: December 31, 2009
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventor: Yasunori Miyazaki
  • Patent number: 7636501
    Abstract: An exemplary optical modulator includes an interferometer. The interferometer includes an input optical coupler, an output optical coupler, and two or more controllable optical waveguides. Each controllable optical waveguide connects the input optical coupler to the output optical coupler and has an electro-absorption modulator along a segment thereof. Two of the controllable optical waveguides are connected to transmit to an output of the output optical coupler light of substantially different maximum amplitude.
    Type: Grant
    Filed: December 31, 2007
    Date of Patent: December 22, 2009
    Assignee: Alcatel-Lucent USA Inc.
    Inventors: Christopher Richard Doerr, Peter J. Winzer
  • Publication number: 20090310901
    Abstract: The modulator includes an optical waveguide positioned on a base. The waveguide is configured to guide a light signal through a light signal-carrying region of a light-transmitting medium. The light signal-carrying region is a region of the waveguide where a fundamental and higher order modes of the light signal are constrained within the waveguide. The modulator also includes a bipolar junction transistor formed in the light-transmitting medium. The bipolar junction transistor is positioned such that causing current to flow through the transistor causes charge carriers to be introduced into the light signal-carrying region of the waveguide.
    Type: Application
    Filed: January 8, 2009
    Publication date: December 17, 2009
    Inventor: Po Dong
  • Publication number: 20090310900
    Abstract: An optical frequency COM generator generating an optical frequency COM having flat spectrum characteristics using a single modulator. The optical frequency COM generator has a drive signal system (11) and a bias signal system (14) which drive a first drive signal (9), a second drive signal (10) and bias signals (12, 13) to satisfy the following expression (I). ?A+??=?/2 (I). (where, ?A and ?? are defined as ?A?(A1?A2)/2 and ???(?1??2)/2, respectively, A1 and A2 represent the amplitudes of the first and second drive signals when they are inputted to the electrodes of the first and second drive signals, respectively, and ?1 and ?2represent the phases of bias voltages applied to first and second waveguides, respectively.
    Type: Application
    Filed: September 22, 2006
    Publication date: December 17, 2009
    Applicant: National Institute of Information and Communicat- ions Technology
    Inventors: Takahide Sakamoto, Tetsuya Kawanishi, Masahiro Tsuchiya, Masayuki Izutsu
  • Patent number: 7630587
    Abstract: An optical waveguide device is disclosed wherein the modulation efficiency for a driving voltage is improved. The optical waveguide device includes a substrate having an electro-optic effect, an optical waveguide formed on the substrate, an electrode section adapted to supply an electric field for carrying out phase modulation synchronized with a clock signal to the optical waveguide, and a Mach-Zehnder interferometer connected to the downstream side of the optical waveguide and including two branching waveguides having optical lengths different from each other.
    Type: Grant
    Filed: April 28, 2008
    Date of Patent: December 8, 2009
    Assignee: Fujitsu Limited
    Inventor: Masaki Sugiyama
  • Patent number: 7630596
    Abstract: A silicon structure includes a silicon substrate; and an on-substrate structure including a silicon compound film and formed on said silicon substrate. At least one removal section removed through anisotropic etching and at least one supporting column left through the anisotropic etching to support said on-substrate structure are provided for a direct lower portion of said silicon substrate directly beneath said on-substrate structure.
    Type: Grant
    Filed: June 27, 2008
    Date of Patent: December 8, 2009
    Inventor: Shinya Watanabe
  • Patent number: 7627213
    Abstract: To reduce wavelength chirp and produce multi-valued signal light that can be readily demodulated on a receiver side, a Mach-Zehnder type optical modulator includes an incident waveguide that branches input light, a pair of optical waveguides that respectively transmit the branched light and exhibit an electro-optic effect, a pair of signal electrodes arranged along the optical waveguides, and an exit waveguide that outputs an interfered light of the light transmitted through the optical waveguides. Furthermore, at a boundary, the polarity of each of the optical waveguides reverses, and either the optical waveguides or the signal electrodes cross each other.
    Type: Grant
    Filed: September 21, 2007
    Date of Patent: December 1, 2009
    Assignee: Fujitsu Limited
    Inventor: Masaki Sugiyama
  • Patent number: 7627200
    Abstract: Optical waveguides (A) and (B) of a Mach-Zehnder modulator is normally formed on a ?Z plane as an electric polarization non-inversion area. However, when the signal electrode 11 and the ground electrode 10 are provided asymmetrically on two waveguides, chirp occurs in output light, which is undesired. Therefore, these electrodes are provided symmetrically about the two waveguides. To effectively perform optical modulation, a part of the substrate in which an optical waveguide exists is to be electric polarization-inverted. As a result of the electric polarization inversion the optical waveguide is on the +Z plane. However, electric charge is accumulated on the +Z plane from unstable spontaneous electric polarization of an electric polarization inversion area, and has undesired influence on the performance of the optical modulator. Therefore, a conductive amorphous layer is formed on the surface of the electric polarization inversion area.
    Type: Grant
    Filed: October 31, 2006
    Date of Patent: December 1, 2009
    Assignee: Fujitsu Limited
    Inventors: Takashi Shiraishi, Tetsu Hasegawa, Masaharu Doi, Kazuhiro Tanaka
  • Publication number: 20090290831
    Abstract: An optoelectronic apparatus for controlling a signal includes an optical waveguide having a variable refractive index; an active device formed within the waveguide, the device having three electrodes, a drain, a source and a gate; and wherein the device is located within the waveguide so that current flowing from the drain to the source changes the refractive index.
    Type: Application
    Filed: August 4, 2009
    Publication date: November 26, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: William Michael John Green, Yurii A. Vlasov
  • Publication number: 20090290830
    Abstract: The invention provides an optical phase modulator having a substrate made of an electro-optical material, a signal electrode provided on the substrate and first and second ground electrodes provided on both sides of the signal electrode. The electrodes are provided so that a size of the first gap between the first ground electrode and the signal electrode is smaller than a size of a second gap between the second ground electrode and the signal electrode. Furthermore, an optical waveguide is provided in the first gap as an optical phase modulator and not provided in the second gap. A driving voltage required for the phase adjustments is thereby lowered, the impedance matching is easily made and excellent radio frequency property can be realized.
    Type: Application
    Filed: July 28, 2009
    Publication date: November 26, 2009
    Applicant: NGK Insulators, Ltd.
    Inventors: Osamu Mitomi, Kenji Aoki, Jungo Kondo, Yuichi Iwata, Tetsuya Ejiri, Akiyoshi Ide
  • Patent number: 7620284
    Abstract: An optical waveform shaping device includes a first waveguide portion, formed on a substrate, for transmitting the optical signal and simultaneously absorbing a portion of the optical signal, which has a signal level equal to or smaller than a predetermined value, so as to shape the optical signal; and a second waveguide portion, formed on the substrate, for transmitting the optical signal, which was transmitted through the first waveguide portion, and simultaneously amplifying the optical signal. The first waveguide portion may be formed using a saturable absorber. A first electrode for supplying electric current to the first waveguide portion so that the first waveguide portion is provided with a function of absorbing the optical signal; and a second electrode for supplying electric current to the second waveguide portion so that the second waveguide portion is provided with a function of amplifying the optical signal may also be provided.
    Type: Grant
    Filed: May 22, 2006
    Date of Patent: November 17, 2009
    Assignee: Yokogawa Electric Corporation
    Inventors: Shinji Iio, Machio Dobashi, Chie Sato, Morio Wada, Katsuya Ikezawa, Akira Miura, Tsuyoshi Yakihara, Shinji Kobayashi, Sadaharu Oka
  • Patent number: 7616843
    Abstract: Arranged for at least one of a pair of branch optical waveguides in a Mach-Zehnder type interference optical system is a ring resonance type phase shifter for modulating a light wave signal propagating through the branch optical waveguide. The ring resonance type phase shifter includes a ring-type optical waveguide arranged so as to be mode-coupled with the corresponding branch optical waveguide, and is configured so that amplitude branching ratio K between the corresponding branch optical waveguide and the ring-type optical waveguide can be varied with a change in refractive index or the like, accompanied by voltage application to a pn junction, for example. As amplitude branching ratio K is varied, the phase difference between the light wave signals propagating through the paired optical waveguides varies, to thereby control the intensity of the light wave signal output from the interference optical system.
    Type: Grant
    Filed: December 26, 2006
    Date of Patent: November 10, 2009
    Assignee: NEC Corporation
    Inventor: Masashige Ishizaka
  • Patent number: 7616618
    Abstract: An optical code division multiple access (OCDMA) system includes an optical transmitter system configured to transmit data from a plurality of users through a shared optical channel by encoding the data from each user with a spreading code assigned to that user. Each spreading code includes a unique sequence of T time chips along a time axis. The data from each user is representable by T symbols. The OCDMA system further includes an optical receiver system configured to demodulate the data from each user by correlating signals received from the transmitter system with the spreading code assigned to that user. When transmitting a data symbol for each user, the transmitter system selects one out of T distinct cyclic shifts of the spreading code assigned to that user, and transmits the selected cyclic shift of the assigned spreading code along the time axis.
    Type: Grant
    Filed: November 29, 2005
    Date of Patent: November 10, 2009
    Assignee: University of Southern California
    Inventors: P. Vijay Kumar, Reza Omrani, Joseph D. Touch, Alan E. Willner, Poorya Saghari
  • Patent number: 7606447
    Abstract: A Mach-Zehnder type semiconductor device includes electrodes for injecting carriers into first and second branch waveguides so as to change reflection indexes of the first and second branch waveguides. The device further includes electrodes which are placed above either one of the first or second branch waveguides or both of the first or second branch waveguides so as to remove the carriers. The Mach-Zehnder type semiconductor device can adjust a phase difference between first and second split light transmitted through the first and second branch waveguides, respectively, even if the lengths of the first and second branch waveguides deviate from designed values. The Mach-Zehnder type semiconductor device also can suppress optical loss of the first and second light, and generate outgoing light without deterioration.
    Type: Grant
    Filed: February 28, 2007
    Date of Patent: October 20, 2009
    Assignee: Oki Semiconductor Co., Ltd.
    Inventor: Hiroshi Wada
  • Patent number: 7603002
    Abstract: An optical device having a substrate having an electro-optical effect, an optical waveguide formed in the substrate, and an electric field emission electrode, and an electric field convergence electrode to which an electric field emitted from the electric field emission electrode converges. The optical waveguide is formed such that light propagating through the optical waveguide passes through an area under the electric field emission electrode or an area under the electric field convergence electrode and then passes through a remaining electrode. As a result, even when an interaction length is increased, the optical device acquires (increases) a modulation index appropriate to the increase in interaction length, thereby diminishing a drive voltage.
    Type: Grant
    Filed: June 6, 2005
    Date of Patent: October 13, 2009
    Assignee: Fujitsu Limited
    Inventor: Masaki Sugiyama
  • Patent number: 7599595
    Abstract: The present invention relates to a semiconductor optoelectronic waveguide having a nin-type hetero structure which is able to stably operate an optical modulator. On the upper and lower surfaces of the core layer determined for the structure so that electro-optical effects are effectively exerted at an operating light wavelength and are provided with intermediate clad layers having a band gap which is greater than that of the core layer 11. Respectively on the upper and the lower surface of the intermediate clad layer are provided the clad layers having the band gap which is greater than those of the intermediate clad layers. On the upper surface of the clad layer are sequentially laminated a p-type layer and an n-type layer. In the applied voltage range used under an operating state, a whole region of the p-type layer and a part or a whole region of the n-type layer are depleted.
    Type: Grant
    Filed: October 4, 2004
    Date of Patent: October 6, 2009
    Assignees: NTT Electronics Corporation, Nippon Telegraph and Telephone Corporation
    Inventors: Tadao Ishibashi, Seigo Ando, Ken Tsuzuki
  • Publication number: 20090232440
    Abstract: It is an object of the present invention to provide an optical modulation system capable of suppressing a carrier component (f0) and a high order component (such as a second order component (f0±2fm)). The optical modulation system includes Mach-Zehnder waveguide (8), a first intensity modulator (9) provided on a first arm (4), a second intensity modulator (10) provided on a second arm (5), a first main Mach-Zehnder electrode (MZCA electrode) (13a), and a second main Mach-Zehnder electrode (MZCB electrode) (13b). Non-desired components propagating the respective arms are made to have reverse phase before optical signals are combined, whereby the optical modulation system is capable of suppressing the non-desired components when the optical signals are combined.
    Type: Application
    Filed: August 30, 2006
    Publication date: September 17, 2009
    Applicant: National Institute of Information and Communications
    Inventors: Tetsuya Kawanishi, Masayuki Izutsu, Takahide Sakamoto, Masahiro Tsuchiya
  • Patent number: 7590312
    Abstract: The present invention discloses an interferometer optical switch that can carry out switching over a broad band and has a high extinction ratio and large fabrication tolerance. The interferometer optical switch employs a phase generating coupler, the phase difference of the output of which has wavelength dependence, as at least one of the optical multi/demultiplexing device included in the interferometer optical switch. A wavelength insensitive interferometer optical switch is implemented by making the sum 2?{?1(?)+??L(?)+?2(?)} constant regardless of the wavelength, where ?1(?) is the phase produced by the first optical multi/demultiplexing device, 2???L(?) is the phase difference of the optical delay line with an optical path length difference of ?L, and 2??2(?) is the phase produced by the second optical multi/demultiplexing device.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: September 15, 2009
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Takayuki Mizuno, Hiroshi Takahashi, Tsutomu Kitoh, Manabu Oguma, Shunichi Souma
  • Patent number: 7590313
    Abstract: A whispering gallery mode (WGM) resonator device and method capable of filtering sidebands of optical modulators are provided. The method includes providing an optical resonator adapted to support whispering gallery modes and forming a first field and a second field from a first location and a second location, respectively, at the circumference of the optical resonator and being separated by an arc angle, ?. The method includes adjusting relative phase between the first field and the second field in accordance to a differential phase, ?, and combining the first and the second fields into an output. Particular selection of the arc angle, ?, and the differential phase, ?, can determine the function of the output.
    Type: Grant
    Filed: October 15, 2008
    Date of Patent: September 15, 2009
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Dmitry V. Strekalov
  • Publication number: 20090220185
    Abstract: The present invention provides an MZ light modulator that can be operated with both of a negative chirp characteristic and a zero chirp characteristic by a single device. The MZ light modulator has first and second waveguides that respectively waveguide two branched lights equal in intensity and perform optical phase modulation by application of first and second modulation voltage signals. Core layers to which modulating electric fields of the first and second waveguides are applied, are different in thickness from each other. The first and second modulation voltage signals are push-pull signals opposite in phase to each other and are different in center voltage from each other.
    Type: Application
    Filed: February 17, 2009
    Publication date: September 3, 2009
    Applicant: OKI SEMICONDUCTOR CO., LTD.
    Inventors: Hiroshi Wada, Tokihiro Terashima
  • Publication number: 20090220235
    Abstract: A modulator is disclosed that includes three arms between a splitter portion and a coupler portion. The modulator typically requires at most a ?/2 phase shift between constellation points. Accordingly, the modulator is more efficient and consumes less power.
    Type: Application
    Filed: December 24, 2008
    Publication date: September 3, 2009
    Inventors: Charles H. JOYNER, Scott CORZINE, Masaki KATO, Mehrdad ZIARI
  • Patent number: 7583868
    Abstract: A full 3R (re-timing, re-shaping, re-amplifying) recovery system is provided. In the full 3R recovery system, a self-pulsating laser diode (SP-LD) and an electroabsorption modulator (EAM) are integrated and disposed on a semiconductor substrate.
    Type: Grant
    Filed: December 6, 2005
    Date of Patent: September 1, 2009
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Dae Su Yee, Young Ahn Leem, Dong Churl Kim, Kyung Hyun Park, Sung Bock Kim
  • Publication number: 20090214150
    Abstract: Provided is an apparatus and method for use thereof. The apparatus, in one embodiment, includes a 1x2 coupler in communication with a waveguide. The 1x2 coupler, in this embodiment, is configured to separate an input finite bandwidth optical signal provided from the optical waveguide into two similar optical signals. Input ends of first and second waveguide arms, in one embodiment, are in communication with the 1x2 coupler and configured to receive ones of the input optical signals. An inherent birefringence of each of the first and second waveguide arms may be substantially similar. Moreover, the first and second waveguide arms have different physical path lengths that differ by an amount (?L). Additionally, a 2x2 coupler may be in optical communication with an output end of the first and second waveguide arms and configured to provide an output TE polarization and an output TM polarization.
    Type: Application
    Filed: February 22, 2008
    Publication date: August 27, 2009
    Applicant: Lucent Technologies, Inc.
    Inventor: Christopher Richard Doerr
  • Patent number: 7580594
    Abstract: An optical modulation element includes a waveguide defined based on a defect in a photonic crystal, a carrier conducting region for conducting a carrier to the waveguide, an electrode for injecting a carrier into the carrier conducting region, and a current control unit for controlling the quantity of carrier to be conducted to the waveguide, wherein the photonic crystal and the electrode are made of a material containing TiO2 as a main composition, and wherein the current control unit functions to change the refractive index of a medium constituting the waveguide in accordance with the quantity of carrier conducted to the waveguide, thereby to modulate the light propagated through the waveguide.
    Type: Grant
    Filed: July 18, 2008
    Date of Patent: August 25, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hikaru Hoshi
  • Publication number: 20090208162
    Abstract: This invention provides a versatile unit cell as well as programmable and reconfigurable optical signal processors (such as optical-domain RF filters) that are constructed from arrays of those unit cells interconnected by optical waveguides. Each unit cell comprises an optical microdisk, an optical phase shifter, and at least one input/output optical waveguide, wherein the microdisk and the phase shifter are both optically connected to a common waveguide.
    Type: Application
    Filed: June 1, 2008
    Publication date: August 20, 2009
    Applicant: HRL Laboratories, LLC
    Inventor: Daniel Yap
  • Patent number: 7577367
    Abstract: Optical techniques, devices and systems for combining duobinary modulation and optical subcarrier multiplexing in optical communication applications. An analog mixer is used to mix a duobinary signal for a data channel and a local oscillator signal to produce a modulation control signal for controlling the subsequent optical subcarrier multiplexing modulation. Various optical subcarrier multiplexing modulation techniques may be used including optical single sideband modulators and optical double sideband modulators.
    Type: Grant
    Filed: June 15, 2005
    Date of Patent: August 18, 2009
    Assignee: Op Vista Incorporated
    Inventor: Winston I. Way
  • Publication number: 20090201575
    Abstract: High power parallel fiber arrays for the amplification of high peak power pulses are described. Fiber arrays based on individual fiber amplifiers as well as fiber arrays based on multi-core fibers can be implemented. The optical phase between the individual fiber amplifier elements of the fiber array is measured and controlled using a variety of phase detection and compensation techniques. High power fiber array amplifiers can be used for EUV and X-ray generation as well as pumping of parametric amplifiers.
    Type: Application
    Filed: February 4, 2009
    Publication date: August 13, 2009
    Applicant: IMRA AMERICA, INC.
    Inventors: Martin E. FERMANN, Ingmar Hartl, Andrius Marcinkevicius, Liang Dong