Acousto-optic Patents (Class 385/7)
  • Patent number: 7430344
    Abstract: An acousto-optic device is disclosed which can achieve both of suppression of secular change and prevention of device damage and can maintain a stabilized wavelength selection filtering operation. The acousto-optic device includes a substrate on which a SAW guide for guiding a surface acoustic wave and an optical waveguide for guiding an optical wave are provided. A pyro-electricity coping conductive wiring pattern is provided in a region of the substrate other than the SAW guide and neutralizes polarization charge generated on a surface of the substrate.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: September 30, 2008
    Assignee: Fujitsu Limited
    Inventors: Hiroshi Miyata, Yukito Tsunoda, Tadao Nakazawa, Yumi Nakazawa
  • Patent number: 7405859
    Abstract: A wavelength selecting apparatus includes a wavelength selecting filter and that a monitoring filter are similar acousto-optic tunable filters; a light source that outputs light having a specific wavelength to the monitoring filter; a light receiving unit that detects a wavelength of light that has passed the monitoring filter; and a control unit that outputs, to the wavelength selecting filter, a control signal having a control frequency to selectively pass light of a desirable wavelength. The light source includes a light emitting element that emits light of a wide wavelength band; and an optical filter having at least two transmission bands through which the light passes to the monitoring filter. The control unit, based on at least two wavelengths of the light output by the light source, outputs a control signal having a control frequency corresponding to the desirable wavelength.
    Type: Grant
    Filed: July 23, 2007
    Date of Patent: July 29, 2008
    Assignee: Fujitsu Limited
    Inventor: Yutaka Takita
  • Patent number: 7400829
    Abstract: A transmission apparatus that receives an optical signal by selecting any one of a plurality of provided optical signal transmission paths through protection control is configured to include a plurality of optical signal outputting sections that output the optical signals transmitted through said optical signal transmission paths respectively as optical signals having wavelengths that are different from each other, a wavelength selective optical switch capable of selectively outputting light of a wavelength corresponding to any one of the optical signals coming from the optical signal outputting sections on the basis of the frequency of a controlling frequency signal, and an optical switch controlling section that supplies said controlling frequency signal to the wavelength selective optical switch so as to output the optical signal coming from the optical signal transmission path side that is selected by said protection control among the optical signals coming from the optical signal outputting sections.
    Type: Grant
    Filed: January 19, 2005
    Date of Patent: July 15, 2008
    Assignee: Fujitsu Limited
    Inventor: Kenji Watanabe
  • Publication number: 20080166120
    Abstract: The present invention relates to the modulation of light traveling along a waveguide, in particular to the acoustic modulation of the light. There is provide a modulator arrangement for acoustically modulating optical radiation. The modulator arrangement has: a waveguide portion formed from a flexible material; a vibrator element for generating acoustic vibrations; and, a coupling arrangement for releasably coupling the vibrating element to the waveguide portion, the coupling arrangement including a first coupling member secured to the waveguide portion, and a second coupling member secured to the vibrator element. The second coupling member is removable from the first coupling member, and the first coupling member has a substantially rigid portion for retaining the shape of the waveguide when the second coupling member is removed from the first coupling member.
    Type: Application
    Filed: March 2, 2006
    Publication date: July 10, 2008
    Inventors: David Heatley, Edmund Sikora
  • Patent number: 7349632
    Abstract: A method of wavelength selection control is disclosed.
    Type: Grant
    Filed: June 3, 2005
    Date of Patent: March 25, 2008
    Assignee: Fujitsu Limited
    Inventors: Masaji Noguchi, Toshihisa Kyouno, Tomohiro Ueno, Hideyuki Miyata, Yasuhiko Aoki
  • Patent number: 7343056
    Abstract: An acoustooptic filter 1 having an optical waveguide 3 disposed on an upper surface 2a of an acoustooptic substrate 2, an interdigital electrode 4 which excites a surface wave disposed on the acoustooptic substrate 2, a surface wave waveguide for the surface wave excited by the interdigital electrode 4 extends in substantially the same direction as the optical waveguide, and a mode of the light guided to the optical waveguide 3 is converted by the surface wave. The acoustooptic filter 1 includes a thin-film ridge 5 as a phase match condition changer that changes a phase match condition at a mutual action area by 0.235% or more from a state in which phases are matched, the mutual action area being an area where the surface acoustic wave and the light guided to the optical waveguide 3 act upon each other.
    Type: Grant
    Filed: April 22, 2004
    Date of Patent: March 11, 2008
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Kiyokazu Yamada
  • Patent number: 7340115
    Abstract: In an optical wavelength tunable filter (AOTF) using an acousto-optic effect of the present invention, there is provided a single SAW waveguide which propagates a surface acoustic wave generated by an IDT along respective arm portions of an optical waveguide. The SAW waveguide is formed with a pair of low sound-velocity areas having a curved belt shape, in which a mode distribution of a propagating SAW is changed symmetrically with respect to a straight line as an axis passing through the middle of the respective arm portions, while keeping the sound velocity of the SAW constant. As a result, wavelength dependence and polarization dependence of the filter property, and an increase in sidelobe level, generated due to weighting of the SAW intensity, can be suppressed.
    Type: Grant
    Filed: November 28, 2005
    Date of Patent: March 4, 2008
    Assignee: Fujitsu Limited
    Inventors: Hiroshi Miyata, Yukito Tsunoda
  • Patent number: 7302128
    Abstract: A fiber optic switch uses induced periodic variations in a multi-mode optic fiber, to control power loss in the switch and power output.
    Type: Grant
    Filed: March 1, 2005
    Date of Patent: November 27, 2007
    Assignee: Florida Institute of Technology
    Inventors: Barry Grossman, Sachin N. Dekarte
  • Patent number: 7302121
    Abstract: The present invention is directed toward an optical device and a drive voltage supply device, which prevent occurrence of a DC drift and enable stable selection of light of desired wavelength without deteriorating a filtering characteristic. The optical device comprises a substrate having an electrooptical effect; an optical waveguide formed in this substrate; a plurality of comb electrode pairs which are arranged side by side along the optical waveguide, can apply an electric field for said electrooptical effect, and are formed from respective pairs of comb electrodes; and drive voltage supply means capable of supplying a drive voltage to said comb electrode pairs such that the voltage changes with time.
    Type: Grant
    Filed: March 22, 2005
    Date of Patent: November 27, 2007
    Assignee: Fujitsu Limited
    Inventors: Yumi Nakazawa, legal representative, Hiroshi Miyata, Yukito Tsunoda, Tadao Nakazawa, deceased
  • Patent number: 7292740
    Abstract: An apparatus (10) and method for dynamic frequency control of a photonic band gap crystal includes an acoustic band gap crystal (12) having a defect site (14), a photonic band gap crystal (20) in the defect site of the acoustic band gap crystal (12), and a sound wave generator (40) coupled to the acoustic band gap crystal (12). Consequently, acoustic waves in the acoustic band gap crystal (12) can be used to controllably alter transmission properties of the photonic band gap crystal (20) and thereby modulate the transmission of electromagnetic radiation through the photonic band gap crystal (20). Acoustic waves in the acoustic band gap crystal (12) can squeeze the photonic band gap crystal (20) to change its properties, including one or more of lattice constant, symmetry, and optical refractive index contrast.
    Type: Grant
    Filed: January 18, 2007
    Date of Patent: November 6, 2007
    Assignee: Raytheon Company
    Inventors: Delmar L. Barker, William R. Owens
  • Patent number: 7269306
    Abstract: A system for exciting flexural waves on an optical fiber (102) is provided. The system includes a substrate (114, 118), an actuator (106), and a mechanical optical fiber coupling (104). The actuator is formed of an electromechanical transducer material. The actuator is mounted on the substrate. The mechanical optical fiber coupling (for example, an adhesive media) forms a secure mechanical connection between the actuator and the optical fiber. The mechanical optical fiber coupling is configured for communicating mechanical vibrations from the actuator to the optical fiber. However, it should be understood that the mechanical optical fiber coupling is exclusive of a tapered horn.
    Type: Grant
    Filed: June 28, 2006
    Date of Patent: September 11, 2007
    Assignee: Harris Corporation
    Inventors: Paul B. Koeneman, Timothy E. Dimmick, Kevin R. Harper, Curtis R. Niemeier, Todd E. Deese, Paul Pilipovich
  • Patent number: 7245789
    Abstract: This document discusses, among other things, an imaging guidewire that includes one or more optical fibers communicating light along the guidewire. At or near its distal end, one or more blazed or other fiber Bragg gratings (FBGs) directs light to a photoacoustic transducer material that provides ultrasonic imaging energy. Returned ultrasound is sensed by an FBG sensor. A responsive signal is optically communicated to the proximal end of the guidewire, and processed to develop a 2D or 3D image. In one example, the guidewire outer diameter is small enough such that an intravascular catheter can be passed over the guidewire. Techniques for improving ultrasound reception include using a high compliance material, resonating the ultrasound sensing transducer, using an attenuation-reducing coating and/or thickness, and/or using optical wavelength discrimination.
    Type: Grant
    Filed: October 7, 2002
    Date of Patent: July 17, 2007
    Assignee: Vascular Imaging Corporation
    Inventors: Kenneth N. Bates, Gil M. Vardi
  • Patent number: 7218797
    Abstract: An acousto-optic device is disclosed which can achieve both of suppression of secular change and prevention of device damage and can maintain a stabilized wavelength selection filtering operation. The acousto-optic device includes a substrate on which a SAW guide for guiding a surface acoustic wave and an optical waveguide for guiding an optical wave are provided. A pyro-electricity coping conductive wiring pattern is provided in a region of the substrate other than the SAW guide and neutralizes polarization charge generated on a surface of the substrate.
    Type: Grant
    Filed: September 22, 2004
    Date of Patent: May 15, 2007
    Assignee: Fujitsu Limited
    Inventors: Hiroshi Miyata, Yukito Tsunoda, Tadao Nakazawa
  • Patent number: 7215837
    Abstract: Optical waveguide systems and methods are described. In one aspect, a display system includes a planar acoustic cavity having a fundamental resonant acoustic mode. The acoustic cavity includes an array of optical waveguides and an array of acoustic transducers. Each of the optical waveguides includes a respective cladding surrounding a liquid-filled core. The array of acoustic transducers is operable to generate acoustic waves that propagate in the acoustic cavity across the cores of the optical waveguides.
    Type: Grant
    Filed: May 10, 2005
    Date of Patent: May 8, 2007
    Assignee: Avago Technologies Fiber IP (Singapore) Pte. Ltd.
    Inventor: William R. Trutna, Jr.
  • Patent number: 7209607
    Abstract: Optical switch matrix having at least an input matrix port defining at least a row of the matrix, a plurality of output matrix ports defining columns of the matrix, a plurality of switching elements, each one being disposed at the intersection of at least one row and one of the columns. Each switch element in a predetermined position of the matrix, in an activated condition, connects an input matrix port to an output matrix port, the ports being correspondents respectively to the predetermined position of the matrix.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: April 24, 2007
    Assignee: Pirelli & C. S.p.A.
    Inventors: Mario Martinelli, Andrea Paganini, Silvia Maria Pietralunga, Andrea Zappettini
  • Patent number: 7209603
    Abstract: The device comprises an optical waveguide and an acoustic wave generating device. The waveguide has an optical band gap and a sharp electronic transition (e.g. an excitonic transition) in the band gap, and the acoustic wave generating device generates acoustic waves within the waveguide. Light passing through the waveguide is of a frequency within the band gap of the waveguide and is nearly resonant with the sharp electronic transition. The wave generating device is arranged to generate acoustic waves so as to induce optical band gas in the polariton spectrum, thereby affecting the transmission of the light passing through the waveguide, the transmission of which is thereby affected.
    Type: Grant
    Filed: September 4, 2002
    Date of Patent: April 24, 2007
    Assignees: University College Cardiff Consultants Limited, Cambridge University Technical Services Limited
    Inventors: Peter Brent Littlewood, Alexander L. Ivanov
  • Patent number: 7187814
    Abstract: A drop-type AOTF is used as a configuration for removing from a through signal an optical signal having the same wavelength as that of an optical signal to be added. To the drop-type AOTF, RF signals are input to always select all of wavelengths, and an RF signal is not input for a wavelength desired to be rejected. As a result, the optical signal having the wavelength for which the RF signal is stopped is not selected by the drop-type AOTF, and cannot pass through. Since there is only one RF signal whose input is stopped, a “drawing effect” does not occur, and control of an optical add/drop device is simplified. Additionally, since high-speed switching can be made, and a wavelength to be added can be varied, restrictions are not imposed on a network configuration.
    Type: Grant
    Filed: October 8, 2004
    Date of Patent: March 6, 2007
    Assignee: Fujitsu Limited
    Inventors: Masaji Noguchi, Toshihisa Kyouno, Hideyuki Miyata, Yutaka Kai
  • Patent number: 7181094
    Abstract: A radio-frequency-signal generator generates an RF signal. An optical monitor monitors a first intensity of a reference signal and a second intensity of a drop signal. A reference-frequency determining unit determines, based on the first intensity, a first frequency of an RF signal that causes the AOTF to output the reference signal. A temperature detecting unit detects a temperature of the AOTF. A frequency calculating unit calculates a second frequency of an RF signal that causes the AOTF to output a drop signal of a desired wavelength. A control unit controls the RF-signal generator to generate the RF signal of the second frequency calculated.
    Type: Grant
    Filed: August 30, 2005
    Date of Patent: February 20, 2007
    Assignee: Fujitsu Limited
    Inventors: Masaji Noguchi, Tomohiro Ueno, Hiroyasu Ito, Hideyuki Miyata, Yutaka Kai
  • Patent number: 7142735
    Abstract: AOTF controller that monitors output power of a plurality of wavelengths of an AOTF and scans the frequency of corresponding RF input signals to an AOTF acoustic transducer and searches for the RF frequency corresponding to each desired wavelength that provides maximum optical output for each wavelength. The controller includes a plurality of sensor inputs for monitoring the power of each wavelength output from the AOTF, and alternatively, also monitors other AOTF parameters such as temperature and/or reads AOTF identification performance data that can be stored in a EPROM on a AOTF housing. The controller includes facility for input of modulation data, and in response to the data modulates the corresponding wavelength parameter such as power. A USB bus is provided for input of programming to the controller, and for output of performance data from the controller.
    Type: Grant
    Filed: April 22, 2005
    Date of Patent: November 28, 2006
    Assignee: Crystal Technology, Inc.
    Inventor: John Kump
  • Patent number: 7120321
    Abstract: The present invention relates to a control method and device for an optical filter, and a primary object of the present invention is to achieve accurate tracking control of the optical filter. Disclosed herein is a control method for an optical filter including first and second optical filter units cascaded, each having an input and first and second outputs. The first output of the first optical filter unit is connected to the input of the second optical filter unit. First light output from the second output of the first optical filter unit is converted into a first electrical signal having a level corresponding to the power of the first light, and second light output from the second output of the second optical filter unit is converted into a second electrical signal having a level corresponding to the power of the second light. A control signal is generated according to the first and second electrical signals. Then, the first and second optical filter units are controlled according to the control signal.
    Type: Grant
    Filed: October 8, 2002
    Date of Patent: October 10, 2006
    Assignee: Fujitsu Limited
    Inventors: Hideyuki Miyata, Yutaka Kai, Isao Tsuyama
  • Patent number: 7068867
    Abstract: A system for monitoring a position of an instrument in a subject includes a light transmission medium configured to transmit light pulses to a desired region to produce an acoustic signal, at least one ultrasound sensor configured to receive the acoustic signal and to produce a transduced signal from the acoustic signal, and a processing unit connected to the at least one ultrasound sensor and configured to locate a source of the acoustic signal using the transduced signal.
    Type: Grant
    Filed: January 2, 2003
    Date of Patent: June 27, 2006
    Assignee: Glucon Medical Ltd
    Inventors: Avner Adoram, Benny Pesach, Ron Nagar, Shai Ashkenazi, Michal Balberg
  • Patent number: 7062109
    Abstract: The present invention relates to an acousto-optic device capable of improving the interaction efficiency for suppressing the driving power needed for SAW generation. The acousto-optic device according to the present invention a substrate showing an acousto-optic effect, first and second optical waveguides formed on the substrate to be substantially parallel with each other for propagating light, a transducer formed on the substrate for producing a surface acoustic wave to be propagated in a propagation direction along directions of the first and second optical waveguides, and a surface acoustic wave distribution structure for distributing an intensity of the surface acoustic wave from the transducer in a direction perpendicular to the propagation direction on the substrate so that maximum values develop at two points corresponding to positions of the first and second optical waveguides.
    Type: Grant
    Filed: October 1, 2004
    Date of Patent: June 13, 2006
    Assignee: Fujitsu Limited
    Inventors: Yukito Tsunoda, Hiroshi Miyata
  • Patent number: 6984819
    Abstract: An ultrasonic receiving apparatus is equipped with such a condition capable of obtaining superior sensitivities. This ultrasonic receiving apparatus includes: an ultrasonic detecting element for modulating light on the basis of ultrasonic waves applied thereto, the ultrasonic detecting element including an ultrasonic sensible portion having a length not larger than ¾ of a wavelength of ultrasonic waves propagated therethrough; and a photodetector for detecting light output from the ultrasonic detecting element.
    Type: Grant
    Filed: May 8, 2002
    Date of Patent: January 10, 2006
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Eiji Ogawa
  • Patent number: 6950566
    Abstract: A method to reduce optical intensity modulation is described that involves generating a spiraling wave onto an acoustic-optic interaction portion of an optical fiber within an acousto-optic filter in order to create reflected waves that are orthogonal with respect to waves that are originally launched onto the interaction portion. A transducer is described having a first section and a second section. The first and second sections each have a polling direction along a first axis. The transducer also has a third section and a fourth section. The third and fourth sections each have a polling direction along a second axis. The third and fourth sections are each between the first and second sections. An acousto-optic filter having a horn with an elliptical cross section coupled to a transducer is also described. A transducer for an excitation element capable of launching spiraling acoustic waves is described.
    Type: Grant
    Filed: August 27, 2003
    Date of Patent: September 27, 2005
    Assignee: Novera Optics, Inc.
    Inventors: Seok-Hyun Yun, Hyo-Sang Kim, In-Kag Hwang, Wayne Victor Sorin, Hee-Yeal Rhy
  • Patent number: 6947220
    Abstract: Devices and methods for information processing in optical communications are provided. In its simplest embodiments, collimated light (1) passes through a non-grating diffractive structure (2) and a lens (3). The light is spatially processed in the focal plane (4) of the lens (3). Thereafter, the light can, for example, be coupled into a fiber or detector array (5).
    Type: Grant
    Filed: November 21, 2000
    Date of Patent: September 20, 2005
    Assignee: KSM Associates, Inc.
    Inventor: Yakov G. Soskind
  • Patent number: 6925229
    Abstract: A first optical waveguide for guiding light is formed on a substrate. A surface acoustic wave transducer for generating a surface acoustic wave which propagates along a direction in which the first optical wave guide guides the light at least partial region of the first optical waveguide, is formed on the substrate. A wavelength variable laser oscillator can be formed which is easy to control and has a fast response speed.
    Type: Grant
    Filed: January 24, 2003
    Date of Patent: August 2, 2005
    Assignee: Fujitsu Limited
    Inventor: Tomoyuki Akiyama
  • Patent number: 6925214
    Abstract: The present invention aims at providing a connecting method capable of suppressing an influence of stray light for a plurality of optical function devices formed on the same substrate, and an optical apparatus applied with the control method. To this end, in the connecting method of optical function devices according to the present invention, the plurality of optical function devices formed on the same substrate are cascade connected so that both ends of an optical path passing through the plurality of optical function devices are positioned on the same end face of the substrate. According to such a connecting method, it becomes possible to effectively suppress a leakage of stray light from an optical input side to an optical output side.
    Type: Grant
    Filed: March 27, 2002
    Date of Patent: August 2, 2005
    Assignee: Fujitsu Limited
    Inventors: Hideyuki Miyata, Yoshihiko Kaitoh, Tadao Nakazawa, Masaharu Doi
  • Patent number: 6922498
    Abstract: A high-speed high-isolation fiber-optic matrix switch using only one acousto-optic device with phased array transducers is disclosed. Previously disclosed fiber-optic switches either required spatially separated more than one acousto-optic devices making them complex, hard to align and expensive or could not achieve high-isolation and low-insertion loss performance. A simple structure of 2×2 fiber-optic matrix switch with one phased array transducer as disclosed here is expected to make acousto-optic based fiber-optic switches more attractive than similar MEMs based switches. Use of shared lens instead of individual lenses at the input and output fiber array is expected to further reduce complexity and cost of the acousto-optic based fiber-optic switches.
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: July 26, 2005
    Assignee: MVM Electronics, Inc.
    Inventor: Manhar L. Shah
  • Patent number: 6909823
    Abstract: A method and apparatus that microbend a fiber Bragg grating with a transverse acoustic wave. The fiber Bragg grating reflects one or more Nth order sidebands of reflection wavelengths an optical signal in order to couple the band of wavelenghts within from a first mode to a second mode.
    Type: Grant
    Filed: December 28, 2001
    Date of Patent: June 21, 2005
    Assignee: Novera Optics, Inc.
    Inventors: Wayne V. Sorin, B. Yoon Kim
  • Patent number: 6904188
    Abstract: This invention relates to an acousto-optical tunable filter generally of the kind described in U.S. Pat. No. 6,266,462. More specifically, the invention relates to a filter and its construction, the filter including a support, first and second mounts at spaced locations on the support, an optical fiber having first and second mounted portions secured to the first and second mounts respectively and a filtering section between the first and second mounted portions, a signal generator operable to generate a periodic signal, and an electro-acoustic transducer having a terminal connected to the signal generator and an actuating portion, the electric signal causing vibration of the actuating portion, and the actuating portion being connected to the filtering section so that the vibration generates a transverse wave traveling along the filtering section. The filter has an improved damper to more effectively dampen waves traveling along the filtering section.
    Type: Grant
    Filed: February 5, 2002
    Date of Patent: June 7, 2005
    Assignee: Novera Optics, Inc.
    Inventors: Seok-Hyun Yun, In-Kag Hwang, Kwan Il Lee, Hyo-Sang Kim, Pavel G. Polynkin, Helge E. Engan, Wayne V. Sorin
  • Patent number: 6891982
    Abstract: An optical waveguide for guided an incident light is formed on a substrate having an electro-optic effect. A first buffer layer is formed to cover an upper surface of the substrate. A conductive film is formed above the first buffer layer. A center electrode and a ground electrode are formed for applying a voltage in order to induce an electric field in the optical waveguide. A second buffer layer is formed between the conductive film and at least one of the center electrode and the ground electrode. The conductive film is formed to be present on at least a part below the ground electrode. A light guided through the optical waveguide is modulated by changing a phase by a voltage applied to the optical waveguide. Thereby, a thermal drift can be effectively restricted so that an optical modulation device having excellent electric characteristics can be realized.
    Type: Grant
    Filed: May 23, 2002
    Date of Patent: May 10, 2005
    Assignee: Anritsu Corporation
    Inventors: Kenji Kawano, Toru Nakahira, Seiji Uchida, Masaya Nanami, Yuji Sato
  • Patent number: 6885807
    Abstract: Unique multi-diffraction structures using electronically controlled Bragg diffraction devices such as acousto-optic (AO) devices to accomplish optical beam attenuation control functions. These variable optical attenuator (VOA) modules can be fully inertialess as they can use electronically programmable sub-microsecond speed AO devices to implement optical gain controls. These VOAs deliver desirable capabilities in one optically reversible unit, making high dynamic range, low loss, high power handling, ultra-fast, high optical isolation, broadband operation, self-aligning robust modules. These VOAs can be made essentially independent of the optical polarization of the incident light by the use of a unique fixed waveplate compensation technique within the VOA configuration that suppresses polarization dependent loss. Broadband gain control operation over several wavelengths can be achieved by controlling the frequency and electrical drive power of the chosen frequencies feeding the acousto-optic devices.
    Type: Grant
    Filed: March 14, 2002
    Date of Patent: April 26, 2005
    Assignee: Nuonics, Inc.
    Inventor: Nabeel Agha Riza
  • Patent number: 6865335
    Abstract: A lightwaveguide panel to be used with a a mobile telephone (MT) or personal digital assistant (PDA), the pannel comprises a first portion for lighting an LCD and/or a keyboard, and a second integral portion, said second portion including a first inclined surface for directing light from a source of light onto a light-reflecting acoustically responsive membrane, and a second inclined surface for directing light from said membrane onto a photo-detector.
    Type: Grant
    Filed: March 25, 2002
    Date of Patent: March 8, 2005
    Assignee: Phone-Or Ltd.
    Inventors: Alexander Paritsky, Alexander Kots
  • Patent number: 6847742
    Abstract: A dynamic gain flattening filter includes a first filter stage. The first filter stage has a first tunable coupling member and a first differential delay with first and second tunable delay paths. The first tunable coupling member adjusts an amount of power of the optical signal that is divided onto the first and second tunable delay paths of the first differential delay.
    Type: Grant
    Filed: March 15, 2001
    Date of Patent: January 25, 2005
    Assignee: Novera Optics, Inc.
    Inventor: Wayne V. Sorin
  • Patent number: 6839473
    Abstract: This invention relates to a method of making optical fiber having low polarization dependence and an acousto-optical filter with low PDL. A section of the fiber is heated and then allowed to cool. At least the heating is controlled to reduce stresses in a cladding layer surrounding a core of the interaction length after the interaction length is allowed to cool to reduce polarization dependence of the cladding layer. Preferably, at least time and temperature of heating is controlled.
    Type: Grant
    Filed: August 30, 2001
    Date of Patent: January 4, 2005
    Assignee: Novera Optics, Inc.
    Inventors: Hyo-Sang Kim, David Vigdor Salamon, Seok-Hyun Yun
  • Publication number: 20040247223
    Abstract: An optical sensor system comprises a plurality of optical fiber sensors, each sensor operative for receiving light pulses at an input thereof and for sensing acoustic pressure and causing a change in a characteristic of the light pulses transmitted therethrough indicative of the sensed pressure. Each optical fiber sensor has a different path length corresponding to a different propagation delay time of the light pulses through that optical fiber. A coupling arrangement imparts the output time delayed pulse signals from each of the plurality of optical fibers into another optical fiber at a single input of the another optical fiber.
    Type: Application
    Filed: June 4, 2003
    Publication date: December 9, 2004
    Inventor: Byron W. Tietjen
  • Publication number: 20040247224
    Abstract: The device comprises an optical waveguide and an acoustic wave generating device. The waveguide has an optical band gap and a sharp electronic transition (e.g. an excitonic transition) in the band gap, and the acoustic wave generating device generates acoustic waves within the waveguide. Light passing through the waveguide is of a frequency within the band gap of the waveguide and is nearly resonant with the sharp electronic transition. The wave generating device is arranged to generate acoustic waves so as to induce optical band gas in the polariton spectrum, thereby affecting the transmission of the light passing through the waveguide, the transmission of which is thereby affected.
    Type: Application
    Filed: May 10, 2004
    Publication date: December 9, 2004
    Inventors: Peter Brent Littlewood, Alexei Ivanov
  • Patent number: 6826327
    Abstract: A method, an apparatus and a system are described for receiving an optical signal in an optical filter and routing the optical signal through the optical filter multiple times.
    Type: Grant
    Filed: December 18, 2001
    Date of Patent: November 30, 2004
    Assignee: Novera Optics, Inc.
    Inventors: Chang-Hee Lee, Wayne V. Sorin, Steven L. Shepherd
  • Patent number: 6807342
    Abstract: A tunable filter with a flattopped passband is provided for use as a micromachined optical filter with input and output optical fibers which provides a wavelength tunability with several discrete wavelengths and a flattopped passband. The standard Fabry-Perot resonator is modified by incorporating multilayer dielectrics to form a pair of interference filters, one of which is vibrated to provide for tunability and provision of several resonant wavelengths. The layers can either be deposited on an existing dielectric slab of a Fabry-Perot device or included on the ends of the input and output optical fibers which are then incorporated into the Fabry-Perot device.
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: October 19, 2004
    Assignee: OpticNet, Inc.
    Inventor: Robert Fan
  • Patent number: 6801686
    Abstract: A method of measuring a power spectrum of an optical signal. The optical signal is transmitted through an optical fiber. A power of at least one wavelength of the optical signal is coupled from a first mode to a second mode of the waveguide. The power of the optical signal coupled from the first mode to the second mode is measured at a detector.
    Type: Grant
    Filed: March 16, 2001
    Date of Patent: October 5, 2004
    Assignee: Novera Optics, Inc.
    Inventor: Wayne V. Sorin
  • Patent number: 6798929
    Abstract: A piezoelectric tunable filter (10) includes a ring (12) made of piezoelectric material surrounding a thin film waveguide (14), and an actuator (17) surrounding the ring. The actuator generates acoustic waves which apply external radial forces on the ring. Because the ring has piezoelectric properties, a periodic, high frequency piezoelectric signal can be generated by the ring and input to the waveguide to produce lattice vibration of the waveguide. The vibration can generate a fluctuating pattern of refractive index in the thin film waveguide due to the modulating effect of the signal. Thus, a periodic radial force of a predetermined frequency produces a desired vibration of the thin films of the waveguide, which in turn produces a desired refractive index in each film, which accordingly changes an optical thickness of each film.
    Type: Grant
    Filed: September 3, 2002
    Date of Patent: September 28, 2004
    Assignee: Hon Hai Precision Ind. Co., LTD
    Inventors: Ga-Lane Chen, Charles Leu, Shu Lin Tai
  • Patent number: 6788834
    Abstract: In a tunable optoacoustic filter, a portion of the optical fiber is coiled around and placed at least partially against a rounded shell equipped with at least one longitudinal slit having an emitter and an absorber on both sides of the slit in contact with the shell or the optical fiber. The emitter transmits elastic waves along the shell and therefore along the fiber to the point of absorber. Coiled configuration of the optical fiber along with various positions of emitters and absorbers are presented allowing to widen the functional range of operation of the filter by increasing the usable length of the optical fiber subject to acoustic oscillations. As a result a reflection/conversion coefficient of up to 0.999 and the filtration band of 1-10 kHz are obtainable.
    Type: Grant
    Filed: September 24, 2002
    Date of Patent: September 7, 2004
    Inventors: Alexei Andreevich Pokrovski, Boris Sergeevich Pavlov, Lev Vassilievich Prokhorov
  • Patent number: 6783282
    Abstract: The present invention aims at providing an optical wavelength filter of band rejection type capable of reliably and stably blocking a light of a desired wavelength from passing through. To this end, the optical wavelength filter of the present invention comprises a plurality of optical filter sections each blocking the light corresponding to the selected wavelength from passing through, the respective optical filter sections being cascade connected to be in a multi-staged structure, wherein the selected wavelengths in the optical filter sections are deviated from one another, to form a blocking band having a wavelength band corresponding to a deviation amount.
    Type: Grant
    Filed: March 27, 2002
    Date of Patent: August 31, 2004
    Assignee: Fujitsu Limited
    Inventors: Tadao Nakazawa, Hideyuki Miyata, Masaharu Doi
  • Publication number: 20040151422
    Abstract: A high-speed high-isolation fiber-optic matrix switch using only one acousto-optic device with phased array transducers is disclosed. Previously disclosed fiber-optic switches either required spatially separated more than one acousto-optic devices making them complex, hard to align and expensive or could not achieve high-isolation and low-insertion loss performance. A simple structure of 2×2 fiber-optic matrix switch with one phased array transducer as disclosed here is expected to make acousto-optic based fiber-optic switches more attractive than similar MEMs based switches. Use of shared lens instead of individual lenses at the input and output fiber array is expected to further reduce complexity and cost of the acousto-optic based fiber-optic switches.
    Type: Application
    Filed: February 5, 2003
    Publication date: August 5, 2004
    Inventor: Manhar L. Shah
  • Patent number: 6754403
    Abstract: An acousto-optical add/drop multiplexer includes an acousto-optical switch including a first optical port coupled to a first polarization splitter, at least one polarization converter coupled between the first polarization splitter and a second polarization splitter, and second and third optical ports coupled to the second splitter. A first circulator is coupled to the first optical port, a mirror is coupled to the second optical port, and a second circulator is coupled to the third optical port. A wavelength selective optical cross-connect may be realized by coupling two such acousto-optical add/drop multiplexers by a single optical fiber to their respective third optical ports.
    Type: Grant
    Filed: April 15, 2002
    Date of Patent: June 22, 2004
    Assignee: Corning Incorporated
    Inventor: Steffen Schmid
  • Publication number: 20040096139
    Abstract: Surface acoustic wave (SAW) zebra-wave-guide (10) implemented as an array of interdigitized electrode fingers, wherein the array has internal inter-finger connectors (18) providing inside electrical shorting of part of fingers (16) remaining other fingers (14) to be isolated, moreover, the array (12) is bordered by important free surface spaces (15). Time delay and phase of the propagating SAW beam front are controlled by the varying of quantity of isolated fingers (14) of the zebra-wave-guide (10). Aggregation (40) of the parallel zebra-wave-guides having different quantities of isolated fingers (14) and different widths allows manipulations with narrow SAW beams' phases and magnitudes, that becomes helpful degree of freedom for desire transformation of the SAW beam (140).
    Type: Application
    Filed: November 10, 2003
    Publication date: May 20, 2004
    Inventor: Yuri Abramov
  • Patent number: 6727767
    Abstract: A voltage controlled oscillator is provided. The oscillator includes a surface acoustic wave element for forming a feedback circuit for an amplifier, and a phase adjustment circuit including a filter which is interposed in the feedback circuit. The oscillator also has a phase shifter including a hybrid coupler to which an additional control part is attached for changing a phase value within an oscillation loop with a control voltage supplied from an external source. An equal power divider equally distributes output power within the oscillation loop and supplies the output power outside the oscillation loop. A multi-layer board is used for mounting the amplifier, surface acoustic wave element, phase adjustment circuit, phase shifter, and equal power divider in at least two separate layers.
    Type: Grant
    Filed: September 10, 2002
    Date of Patent: April 27, 2004
    Inventor: Yutaka Takada
  • Publication number: 20040067000
    Abstract: This document discusses, among other things, an imaging guidewire that includes one or more optical fibers communicating light along the guidewire. At or near its distal end, one or more blazed or other fiber Bragg gratings (FBGs) directs light to a photoacoustic transducer material that provides ultrasonic imaging energy. Returned ultrasound is sensed by an FBG sensor. A responsive signal is optically communicated to the proximal end of the guidewire, and processed to develop a 2D or 3D image. In one example, the guidewire outer diameter is small enough such that an intravascular catheter can be passed over the guidewire. Techniques for improving ultrasound reception include using a high compliance material, resonating the ultrasound sensing transducer, using an attenuation-reducing coating and/or thickness, and/or using optical wavelength discrimination.
    Type: Application
    Filed: October 7, 2002
    Publication date: April 8, 2004
    Inventors: Kenneth N. Bates, Gil M. Vardi
  • Patent number: 6718076
    Abstract: An acousto-optic tunable filter that includes a polarization beamsplitter, a multi-segment interaction region and a polarization beam combiner is described. The polarization beamsplitter generates a first and a second polarized optical signal. The multi-segment optical interaction region includes a first optical interaction region and a first acoustic wave generator that generates acoustic waves in the first optical interaction region. The multi-segment optical interaction region also includes a second optical interaction region that is non-collinear relative to the first optical interaction region and a second acoustic wave generator that generates acoustic waves in the second optical interaction region. Optical signals that are phase-matched to the acoustic waves are mode-converted in response to the acoustic waves. The acousto-optic tunable filter also includes a polarization beam combiner that generates both a mode-converted optical signal and a non-mode-converted optical signal.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: April 6, 2004
    Assignee: Unaxis USA, Inc.
    Inventors: Kenneth J. Bures, Dogan Gunes, Chunghsin Lee, Paul Maki, Piero Sferlazzo
  • Patent number: 6701031
    Abstract: An acousto-optical tunable filter capable of appropriately filtering lights with a plurality of frequencies, a method of driving the same, and an optical add/drop multiplexer using the same. The acousto-optical tunable filter includes a signal source which supplies an RF frequency to the acousto-optical tunable filter; a control part which controls the RF frequency of the signal source; and a compensation part which determines an RF frequency for selecting one light from a plurality of lights with different frequencies from each other by adding/subtracting a predetermined compensation amount to/from an RF frequency for selecting only one light, when selecting the plurality of lights in the acousto-optical tunable filter, determines all of a plurality of RF frequencies for selecting the plurality of lights, and designates the control part to oscillate the determined RF frequencies.
    Type: Grant
    Filed: July 27, 2001
    Date of Patent: March 2, 2004
    Assignee: Fujitsu Limited
    Inventor: Tadao Nakazawa