With Particular Direction Of The Field In Relation To The Medium, Beam Direction Or Polarization Patents (Class 359/251)
  • Patent number: 7403677
    Abstract: An apparatus and method to operate on a light beam by using a lens that collimates the light beam to a collimated beam with at least one cross-sectional dimension less than a critical dimension of 400 ?m or less over a working range WR. The apparatus has a bulk electro-optic material of small thickness ?, e.g., less than 300 ?m positioned within working range WR and the collimated beam traverses it along its path. The apparatus has a voltage source for applying a low operating or drive voltage Vdrive, e.g. less than 400 V to the bulk electro-optic material for performing an operation on the collimated beam. The lens for collimating the light beam is a free-space collimator such as a graded index (GRIN) lens or preferably a C-lens. The apparatus is a versatile and scalable platform that can be employed in building various electro-optic devices.
    Type: Grant
    Filed: August 30, 2005
    Date of Patent: July 22, 2008
    Assignee: Agiltron, Inc.
    Inventors: Jing Zhao, Jin Guanghai, Shu Yongjun
  • Patent number: 7357511
    Abstract: Some projection systems use a polarization beamsplitter (PBS) for coupling light to and from an image-forming device. The PBS is typically formed with a reflective polarizing layer disposed between glass covers. Stress birefringence in the glass cover lying between the reflective polarizing layer and the image-forming device can reduce the image contrast of the projection system. A quarter-wave retarding element positioned between the glass cover and the image-forming device is used to compensate for the birefringence, at least in part. This permits the PBS to use glass covers formed of a glass material having a higher stress optic coefficient than before, while still maintaining high image contrast.
    Type: Grant
    Filed: March 23, 2005
    Date of Patent: April 15, 2008
    Assignee: 3M Innovative Properties Company
    Inventors: David J. W. Aastuen, Charles L. Bruzzone, Jiaying Ma
  • Patent number: 7324257
    Abstract: The invention relates to an electro-optic modulator structure containing an additional set of bias electrodes buried within the device for applying bias to set the operating point. Thus the RF electrodes used to modulate incoming optical signals can be operated with zero DC bias, reducing electrode corrosion by galvanic and other effects that can be present in non-hermetic packages. The buried bias electrodes are also advantageous in controlling charge build-up with consequent improvement in drift characteristics. The bias electrode material is useful for routing bias signals inside the device, in particular to external terminals, as well as forming encapsulating layers to permit operation in non-hermetic environments, thereby lowering manufacturing costs. Embodiments using both X-cut and Z-cut lithium niobate (LiNbO3) are presented. For the latter, the bias electrodes can be split along their axis to avoid optical losses.
    Type: Grant
    Filed: July 26, 2005
    Date of Patent: January 29, 2008
    Assignee: JDS Uniphase Corporation
    Inventors: Gregory J. McBrien, Karl Kissa, Glen Drake, Kate Versprille
  • Patent number: 7295360
    Abstract: A structure includes a substrate and a light modulating film formed on top of the substrate. The light modulating film is made of polycrystalline PLZT containing Pb, Zr, Ti, and La as constituent elements. The film has a La concentration in the range of 5 at % to 30 at %. The relative dielectric constant at a frequency of 1 MHz is higher than or equal to 1200.
    Type: Grant
    Filed: February 3, 2006
    Date of Patent: November 13, 2007
    Assignee: Rohm Co., Ltd.
    Inventors: Yoshikazu Fujimori, Takashi Nakamura
  • Patent number: 7291829
    Abstract: A polarization separating element such as a beam splitter receives a first light of a first polarization plane. The polarization separating element derives out of the first light a second light of a second polarization plane set perpendicular to the first polarization plane. A photoelectric element converts the second light into an electric signal. The intensity of the second light is in this manner detected. Since the second light is derived out of the first light, the phase of the second light is allowed to synchronize with the phase of the first light. The extinction ratio of the second light accurately reflects the extinction ratio of the first light. The detection of the intensity of the second light at the photoelectric element enables an accurate detection of the intensity of the first light.
    Type: Grant
    Filed: September 21, 2005
    Date of Patent: November 6, 2007
    Assignee: Fujitsu Limited
    Inventor: Masaki Iwamoto
  • Patent number: 7274347
    Abstract: Methods and apparatus are provided for preventing charge accumulation in microelectromechanical systems, especially in micromirror array devices having a plurality of micromirrors. Voltages are applied to the micromirrors for actuating the micromirrors. Polarities of the voltage differences between mirror plates and electrodes are inverted so as to prevent charge accumulation.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: September 25, 2007
    Assignee: Texas Instruments Incorporated
    Inventor: Peter R. Richards
  • Patent number: 7206116
    Abstract: A Faraday rotator for a Faraday isolator with an input polarizer, with an output polarizer, with a roller-shaped optical crystal that is arranged therebetween and that is arranged symmetrical to its axis of symmetry, with a right hollow cylinder that surrounds this and has a hollow space made of a permanent magnetic material, which cylinder is axially magnetized and the magnetic field of which extends in the hollow space approximately parallel to the axis of symmetry that runs in only one direction from the north pole to the south pole, and with terminal magnets attached to each of the two end faces in the plane perpendicular to the y- and z-directions of the axis of symmetry, each of which is embodied as a hollow right cylinder and has a through-aperture in the extension of the axis of symmetry, is characterized in that each terminal magnet is largely radially magnetized with regard to the axis of symmetry at least by region, in that the one of the two terminal magnets is magnetized radially from interior to
    Type: Grant
    Filed: April 21, 2004
    Date of Patent: April 17, 2007
    Assignee: Linos Photonics GmbH & Co. KG
    Inventors: Thomas Fehn, Sven Poggel, Stefan Balle
  • Patent number: 7192147
    Abstract: The invention provides a compact, thin, and lightweight lighting system and projector. A lighting system included in a projector according to the present invention is provided with an LED array having LEDs and a reflective plate at the rear side of the LEDs in the light emitting direction, retardation films, a taper rod lens array, a rod lens array, and a reflective polarizing plate.
    Type: Grant
    Filed: May 9, 2003
    Date of Patent: March 20, 2007
    Assignee: Seiko Epson Corporation
    Inventors: Hidefumi Sakata, Takashi Takeda
  • Patent number: 7110623
    Abstract: A corner cube utilized for both a polarization transformer and a depolarizer requires a special glass for the corner cube. For the transformer a polarized probe beam irradiates only one facet of the corner cube off-axis to vertex, whereas for the depolarizer a circularly polarized beam irradiates all three facets symmetrically on-axis to the cube vertex. The collimated output beam from the corner cube has a hexad pattern where alternate hexads correspond to CW (clockwise) and CCW (counter-clockwise) rotations in sequential reflections from the corner cube facets. CW and CCW hexad regions comprising the depolarized beam differ in phase by 0.8? radians. A dielectric layer pattern of alternate hexads deposited on the output port of a beam director in registry to the depolarized beam pattern compensates for the leading phase of the CCW hexads thus equalizing the overall phase-front of the beam and thereby resulting in a temporally-coherent depolarized beam.
    Type: Grant
    Filed: January 23, 2004
    Date of Patent: September 19, 2006
    Inventor: Ralph Kalibjian
  • Patent number: 7095559
    Abstract: In a variable optical delay circuit to be used for compensation for polarization mode dispersion of an optical signal and for other purposes, there are provided a first birefringent member, a second birefringent member and a variable optical rotator interposed between the first birefringent member and the second birefringent member for varying a polarization state of light outputted from the first birefringent member. The birefringent members and the variable optical rotator are disposed on the same optical axis, and the optical axis of each of the birefringent members is set to perpendicularly intersect a traveling direction of inputted light. Therefore, by varying the optical rotation angle of the variable optical rotator, an arbitrary delay quantity corresponding thereto is obtainable in a continuous (analog-like) fashion without undergoing spatial separation between polarization components of the inputted light and varying the intensity (loss) of each of the polarization components.
    Type: Grant
    Filed: March 23, 2005
    Date of Patent: August 22, 2006
    Assignee: Fujitsu Limited
    Inventors: Shinji Taniguchi, Tadao Nakazawa, deceased, Yumi Nakazawa, legal representative, Masaharu Doi
  • Patent number: 7057787
    Abstract: An electro-optic crystal based beam-steering device preferably based on KTN, having a first deflector and a second deflector. The first deflector has a pair of substrates each having a plurality of first electrode lines extending along a first direction and a plurality of electro-optic crystal modulators interposed between the first electrode lines. The second deflector has a pair of substrates each having a plurality of second electrode lines extending along a second direction and a plurality of electro-optic crystal modulators interposed between the second electrode lines. The first direction is orthogonal to the second direction.
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: June 6, 2006
    Assignee: Northrop Grumman Corporation
    Inventors: James M. Cicchiello, Curtis J. Harkrider
  • Patent number: 7042610
    Abstract: Optical components are louvered with a light absorptive material that absorbs stray light rays. The louvers are constructed, for example, using a “black” thin film coating between sheets of glass. The louvered components are placed in an optical path at one or more orientations. In one embodiment, a vertically oriented louvered component and a horizontally oriented louvered component are individually located in a light path to reduce and/or eliminate stray light having either horizontal and/or vertical vector components. Compensated higher order waveplates are constructed from birefringent material by placing two higher order waveplates (a n? waveplate and a (n+?)? waveplate.) in proximity to each other such that their principle retardation axes are perpendicular. In one embodiment, the higher order waveplates include louvers for stray light suppression.
    Type: Grant
    Filed: May 12, 2004
    Date of Patent: May 9, 2006
    Assignee: LightMaster Systems, Inc.
    Inventor: Arthur Berman
  • Patent number: 7031066
    Abstract: An integrator of an optical device using a color drum is disclosed. The integrator includes an opening receiving a light generated from a lamp, an optical path part reflecting and passing forward the light received at the opening, a mirror part refracting and totally reflecting the light passed through the optical path part and changing a direction of the light being transmitted, a polarization plate transmitting light rays having a constant polarization direction, among the reflected light, and reflecting remaining light rays having other polarization directions, and a wave plate changing a phase of the light reflected from the polarization plate.
    Type: Grant
    Filed: June 29, 2004
    Date of Patent: April 18, 2006
    Assignee: LG Electronics Inc.
    Inventors: Ho Joong Kang, Jong Myoung Park
  • Patent number: 7023603
    Abstract: A micro-mirror device includes a substrate having a surface, and a plate spaced from and oriented substantially parallel to the surface of the substrate such that the plate and the surface of the substrate define a cavity therebetween. A dielectrophoretic microemulsion capable of movement when an electrical signal is applied to the micro-mirror device is disposed in the cavity, and a reflective element is interposed between the surface of the substrate and the plate such that the reflective element is adapted to move between a first position and at least one second position. The dielectrophoretic microemulsion has a continuous oil phase.
    Type: Grant
    Filed: December 23, 2003
    Date of Patent: April 4, 2006
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Paul F. Reboa
  • Patent number: 6963441
    Abstract: An electro-optically deactivated transmissive material comprises a plurality of chemicals which are sufficient, in combination, to enable formation of an electro-optic material having an index of refraction that is responsive to an electric field. The chemicals are combined with a glassifier so as to form a transmissive material that is less responsive to the electric field than said electro-optic material. The deactivated material has substantially the same refractive index as the electro-optic material in the absence of an electric field. In a preferred embodiment, the deactivated material is arranged with active material to form an optical switch.
    Type: Grant
    Filed: June 26, 2001
    Date of Patent: November 8, 2005
    Assignee: Teloptics, Corporation
    Inventor: Gene H. Haertling
  • Patent number: 6888659
    Abstract: A polarization controller comprising means for generating linearly polarized light and at least one liquid crystal cell. A preferred embodiment of the invention comprises a linear polarizer and two liquid crystal cells. In the preferred embodiment, the polarization direction of the polarizer and the orientation of the fast axis of the first and second liquid crystal cells are oriented in a manner that allows the linearly polarized light provided by the polarizer to be transformed into any state of polarization at the output of the second liquid crystal cell. The present invention provides full coverage of the Poincaré sphere.
    Type: Grant
    Filed: December 10, 2002
    Date of Patent: May 3, 2005
    Assignee: JDS Uniphase Inc.
    Inventor: Louis B. Allard
  • Patent number: 6865006
    Abstract: “This invention offer optical modulator module with fulfilling the effective and the stable optical modulation, which stabilizes the emission of semiconductor and control the shift of optic axis between the optical component by the temperature change and so on, when using the semiconductor laser. Peculiarly, the optical modulator module includes, in same package, the semiconductor laser (27) as light source, the optical modulation device (28) that has optical waveguide on the surface of the chip made by the element of the electro-optical effect, and the polarization rotating element (40) between said semiconductor laser and said optical modulation device, for bringing plane of polarization of light from said semiconductor laser (27) to optimum plane of polarization in waveguide of the said optical modulation device in line and blocking the returning light from said optical modulation device to said semiconductor laser.
    Type: Grant
    Filed: April 1, 2003
    Date of Patent: March 8, 2005
    Assignee: Sumitomo Osaka Cement Co., Ltd.
    Inventors: Toshio Sakane, Tsutomu Saitou, Susumu Murata
  • Patent number: 6765670
    Abstract: The present invention relates to a spectrometer module comprising an input, for receiving an incoming optical signal, a variable differential group delay (DGD) element, for applying a variable birefringence retardation to said incoming optical signal, and a detector unit for detecting the power of a signal exiting said variable DGD element, having a defined state of polarization. It also relates to a monitor module, a monitoring unit and a monitoring system, comprising such a spectrometer module for use in monitoring an optical network. Further, the invention relates to a spectrometer device, for spectrometry purposes, comprising a spectrometer module as stated above.
    Type: Grant
    Filed: November 27, 2001
    Date of Patent: July 20, 2004
    Assignee: Pro Forma Alfa
    Inventors: Bengt-Erik Olsson, Magnus Karlsson, Henrik Sunnerud
  • Patent number: 6760140
    Abstract: An optical interconnection device and a spot displacement device are presented. In optical interconnection device of the present invention, a spot displacement device is employed to cause a light beam to shift positions, thereby making available output positions not previously available for a light beam having bounced so few times.
    Type: Grant
    Filed: March 1, 2002
    Date of Patent: July 6, 2004
    Assignee: The Ohio State University Research Foundation
    Inventors: Victor Argueta-Diaz, Betty Lise Anderson, Stuart A. Collins, Jr.
  • Patent number: 6751002
    Abstract: An optical polarization modulator (OPM) for use in an optical communication system includes two polarizing beam splitters (PBSs) and an adjusting stage coupled between the PBSs. One PBS receives an input optical signal with an arbitrary state of polarization (SOP) and splits it into its TE and TM components. The adjusting stage can change the amplitude and/or relative phase between the TE and TM components to help achieve a desired state of polarization (SOP). The ACS and PCS may include MZIs to both adjust the amplitude and the relative phase difference between the TE and TM components. Alternatively, the OPM may include an amplifier and a phase shifter for each component. The second PBS combines the adjusted components to form the output signal with a desired SOP. Another embodiment of the OPM includes an Y-junction coupler, two plasma optical-effect silicon phase shifter stages, a 2×2 3-dB coupler and a PBS.
    Type: Grant
    Filed: May 6, 2002
    Date of Patent: June 15, 2004
    Assignee: Intel Corporation
    Inventors: Shlomo Ovadia, Ansheng Liu, Remus Nicolaescu
  • Patent number: 6738174
    Abstract: The invention discloses phase-shifters, modulators, and method that produces a smaller &pgr; by means of a field excitation using multiple electrodes. A negative signal is introduced that travels with the positive signal, which enhances the electric field significantly. The field enhancement is provided by the superposition of the fields accumulated from each electrode. A base or substrate material can be made from any compound having linear electro-optic properties, such as lithium niobate, lithium tantalite, potassium lithium niobate, potassium titanyl phosphate or gallium-arsenide. For lithium niobate, there are two possible orientations of electric field, z-cut orientation or x-cut orientation.
    Type: Grant
    Filed: February 23, 2001
    Date of Patent: May 18, 2004
    Assignee: Big Bear Networks, Inc.
    Inventors: Marc E. Hill, Jonathan P. King, Hui Wu
  • Patent number: 6717710
    Abstract: An electro-modulating device for modulating light from a light source, as part of an opto-electronic communication network has a modulating medium for modulating light passing therethrough by varying an electric field applied across the modulating medium, an optical input-output surface, a light reflector, and electrodes for applying the varying electric field across the modulating medium. The input-output surface, the medium and the reflector are arranged so that light enters the medium through the input-output surface, travels through the medium towards the reflector, is reflected by the reflector to travel back through the medium towards the input-output surface, and exits the medium through the input-output surface. The electric field is transverse to light traversing the medium between the input-out surface and the reflector, to make it easier to couple an optic fiber to the input-output surface of the modulating medium.
    Type: Grant
    Filed: January 14, 2002
    Date of Patent: April 6, 2004
    Assignee: Agilent Technologies, Inc.
    Inventor: Christopher Anthony Park
  • Patent number: 6714743
    Abstract: A wide range tunable filter is provided. A randomly polarized incoming beam is converted into two orthogonally polarized beams. A ½ wave plate and filter block turns these two beams into four beams. Two of the four beams have a single range of wavelengths and two beams have the remaining wavelengths. Each pair of beams is orthogonally polarized. A ½ wave plate and birefringent crystal positioned after the filter block combine the two beams having the single range of wavelengths and combines the two beams having the remaining wavelengths. The invention includes a thermal compensator to correct the angle of the filter with respect to the incident light.
    Type: Grant
    Filed: March 19, 2001
    Date of Patent: March 30, 2004
    Assignee: Optoplex Corporation
    Inventors: Yung-Chieh Hsieh, Chiayu Ai, Chang-Tsung Lin
  • Patent number: 6690501
    Abstract: A method and system for providing an isolator/polarization beam deflector is disclosed. The method and system include a first collimator, a core and a second collimator. The first collimator collimates a plurality of optical signals traveling in a first direction. The core receives the optical signals from the first collimator. The core includes first and second birefringent wedges and a rotator between the first and second birefringent wedges. The first collimator, the first birefringent wedge and the rotator transmit the optical signals such that the optical signals cross at an interface between the rotator and the second birefringent wedge. The core transmits the optical signals with a deflection, combines the optical signals to provide a combined optical signal and prevents a reflected portion of the optical signals from traveling opposite to the first direction. The second collimator receives and couples the combined optical signal to the output.
    Type: Grant
    Filed: January 3, 2002
    Date of Patent: February 10, 2004
    Assignee: AC Photonics, Inc.
    Inventors: Yiqiang Li, Yongjian Wang
  • Publication number: 20040012836
    Abstract: Electrooptic devices (100, 600, 700) include a left handed (102, 708) and right handed (104, 710) cholesteric phase liquid crystal layers. Electrodes (120, 122, 124, 126, 602, 604) or magnetic coils (704, 706) are used to apply electric or magnetic fields perpendicular to helical axes of the cholesteric phase liquid crystal layers. The fields lengthen the helical pitch of the liquid crystal layers thereby shifting the reflectance of the liquid crystal layers to longer wavelengths. Spectral reflectance of both left and right hand polarized light is controlled by the electrooptic devices.
    Type: Application
    Filed: July 16, 2002
    Publication date: January 22, 2004
    Inventor: Zili Li
  • Patent number: 6665106
    Abstract: The invention specifies a method and apparatus for optical polarization control which enable non-ideal component behavior to be corrected by means of a calibration table. This ensures shorter constructional length, lower operating voltages or higher level functions (ER instead of GSBA).
    Type: Grant
    Filed: May 25, 2001
    Date of Patent: December 16, 2003
    Inventor: Reinhold Noe
  • Patent number: 6614572
    Abstract: An apparatus for processing an optical beam has at least one variable optical element to dynamically alter the polarization state of a polarized optical beam to form a polarization-altered optical beam. The polarization-altered optical beam includes elliptical polarization. The at least one variable optical element is a compound birefringent crystal with a designed retardation response to temperature variations. In one embodiment, the compound birefringent crystal has a designed retardation response that is substantially invariant with operating temperature variations. At least one wave plate processes the polarized optical beam. Each wave plate has a selected retardation, order of retardation, and orientation.
    Type: Grant
    Filed: May 17, 2002
    Date of Patent: September 2, 2003
    Assignee: CoAdna Photonics, Inc.
    Inventors: Jack R. Kelly, Haiji J. Yuan, Hudson Washburn
  • Patent number: 6594063
    Abstract: A polarization independent optical device is provided wherein the device has two optical paths that include one or more birefringent crystals, a electrically controllable rotator, and a fixed waveplate. The device may operate as a switch, attenuator, coupler, or polarization mode dispersion compensator. The device may also include several folded path embodiments, a multifunctional embodiment, and a temperature insensitive embodiment.
    Type: Grant
    Filed: September 15, 2000
    Date of Patent: July 15, 2003
    Assignee: SpectraSwitch, Inc.
    Inventors: Brent Bergner, Richard Albert, D. L. Seekola
  • Patent number: 6570710
    Abstract: A light collimating film has a sheeting having a first side and a second side, wherein the first side includes a series of linear optical elements having a primary axis running the length of the optical elements, and the second side includes a plurality of subwavelength optical microstructures being oriented at about 90 degrees relative to the primary axis of the linear optical elements. Another embodiment includes a back lighting display device having a lighting device, a display panel, and a sheeting having a first side and a second side, wherein the first side includes a series of linear prisms having peaks, and the second side includes a plurality of subwavelength optical microstructures being oriented at about 90 degrees relative to the peaks of the linear prisms.
    Type: Grant
    Filed: October 6, 2000
    Date of Patent: May 27, 2003
    Assignee: Reflexite Corporation
    Inventors: Robert B. Nilsen, Patrick W. Mullen, Xiao-Jing Lu
  • Publication number: 20030086144
    Abstract: A real-time optical compensating apparatus reduces the PMD in an optical fiber by determining the principal states of polarization of the optical fiber and delaying one principal state of polarization with respect to the other.
    Type: Application
    Filed: February 15, 2001
    Publication date: May 8, 2003
    Inventors: Patrick C. Chou, John M. Fini, Hermann A. Haus
  • Patent number: 6552838
    Abstract: An electro-optic modulator and associated method are provided. The electro-optic modulator includes an optical waveguide comprised of two pairs of coplanar modulation strips, the strips being driven by a controller circuit which applies voltages of equal amplitude and opposite polarity to the strips of each pair. The voltage applied to the first pair of strips may differ from the voltage applied to the second pair of strips, so that a chirp factor may be adjusted if desired. The modulator and associated method exhibit reduced drive voltage requirements.
    Type: Grant
    Filed: July 18, 2001
    Date of Patent: April 22, 2003
    Assignee: Agere Systems Inc.
    Inventors: Johannes G. Ransijn, James D. Yoder
  • Publication number: 20030072069
    Abstract: A method and system for providing an isolator/polarization beam deflector is disclosed. The method and system include a first collimator, a core and a second collimator. The first collimator collimates a plurality of optical signals traveling in a first direction. The core receives the optical signals from the first collimator. The core includes first and second birefringent wedges and a rotator between the first and second birefringent wedges. The first collimator, the first birefringent wedge and the rotator transmit the optical signals such that the optical signals cross at an interface between the rotator and the second birefringent wedge. The core transmits the optical signals with a deflection, combines the optical signals to provide a combined optical signal and prevents a reflected portion of the optical signals from traveling opposite to the first direction. The second collimator receives and couples the combined optical signal to the output.
    Type: Application
    Filed: January 3, 2002
    Publication date: April 17, 2003
    Inventors: Yiqiang Li, Yongjian Wang
  • Patent number: 6525860
    Abstract: An electronically variable light attenuator and method for electronically attenuating light. The attenuator has an array of liquid crystal regions. The regions in a first set thereof are interspersed with the regions in a second set thereof. The array is adapted to receive a beam of light directed along an axis. A pair of electrodes is provided. At least one of the sets of regions is disposed between the electrodes. The regions in the first set are configured to produce a first diffraction pattern in response to the received light and the regions in the second set are configured to produce a second diffraction pattern in response to the received light. The pair of electrodes are arranged to enable the first and second diffraction patterns to combine with a degree of interference along an axis selected in accordance with an electric field produced between the pair of electrodes and through the at least one of the sets of regions.
    Type: Grant
    Filed: May 18, 2000
    Date of Patent: February 25, 2003
    Assignee: Raytheon Company
    Inventors: Michael Holz, David L. Corkum
  • Publication number: 20020181066
    Abstract: The invention is an instrument for sensing the state of polarization (SOP), and for transforming the SOP of a beam of light from an incident continuously-varying arbitrary SOP to a desired exit SOP, using a polarization compensator under feedback control. A polarization sensor uses two or three samples of a beam to sense the Poincare sphere latitude and longitude error in SOP. A polarization controller adjusts the SOP of light, which is then sensed by the polarization sensor, which develops signals to drive the polarization compensator using feedback methods. Unlike prior-art systems, the feedback seeks a mid-point rather than an extremum in the sensed signals, so there is no sign ambiguity in the feedback control. Further, the sensor signals indicate orthogonal displacements in SOP that correspond to specific elements in the polarization controller, so there is no ambiguity as to which element needs adjustment in order to correct a given error in SOP.
    Type: Application
    Filed: December 11, 2001
    Publication date: December 5, 2002
    Applicant: Cambridge Research & Instrumentation, Inc., a Delaware corporation
    Inventor: Peter J. Miller
  • Publication number: 20020181067
    Abstract: An optical system (10) includes an optical switching module (210,300,350) that is adjustable between first and second conditions to selectively direct an incident light signal (240,301,351) between either of at least two optical paths (236,238,304,303). At least one optical switch (218) is integrated into a substantially planar waveguide substrate in order selectively switch light (240,301,351) entering the switch from one waveguide (232,234) to exit the switch along either of at least two other waveguides (236,238). The optical switch (218) includes an electro-optic material (222) that is deposited into a cavity (220) formed within the substrate (214) such that the respectively optically coupled waveguides (232,234,236,238) interface with the switch (218) along the cavity walls.
    Type: Application
    Filed: November 5, 2001
    Publication date: December 5, 2002
    Inventors: Alexander B. Romanovsky, Gene H. Haertling
  • Publication number: 20020159670
    Abstract: A device for adjusting the polarization of an incoming optical signal with a polarization divider (1), a first phase setter (3) in the signal path of at least one of the two output signals from the polarization divider, a first optical coupler (4), a second phase setter (5) in the signal path of at least one of the two output signals from the first optical coupler, and with a second optical coupler (6), an actuating signal being supplied to the phase setters respectively in a feedback loop, said actuating signal being obtained from a quality signal derived from the processed optical signal, is characterized in that a substraction element (10) is provided, to which the two parallel optical signals are supplied from a point after the first optical coupler, a bipolar quality signal being obtained in the substraction element from the difference of the two signals supplied, and that a control element (11) is connected downstream of the substraction element, which control element generates an actuating signal to on
    Type: Application
    Filed: April 5, 2002
    Publication date: October 31, 2002
    Applicant: ALCATEL
    Inventor: Henning Bulow
  • Publication number: 20020154377
    Abstract: A optical phased array device for optical beams with general polarization. A reflective embodiment of the inventive optical phased array interposes a quarter-wave plate between a linearly polarized liquid crystal layer and a mirror. A controllable voltage applied across the liquid crystal layer causes a first linearly polarized component of an incident optical beam to be phase shifted when it passes through the liquid crystal layer. The polarization of the optical beam is rotated by 90° when it travels through the quarter-wave plate, is reflected from the mirror, and travels back through the quarter-wave plate. The second linearly polarized component of the optical beam, orthogonal to the first, is phase shifted when it passes back through the liquid crystal layer. A transmissive embodiment of the inventive optical array interposes a half-wave plate between two linearly polarized liquid crystal layers.
    Type: Application
    Filed: January 11, 2001
    Publication date: October 24, 2002
    Applicant: HRL Laboratories, LLC
    Inventor: David M. Pepper
  • Publication number: 20020135852
    Abstract: The present invention uses quantum interference of one and two photon absorption from a multiple color fields to optically inject ballistic spin currents in unbiased photoconductors. The spin currents can be generated with and without an accompanying electrical current and can be controlled using the relative phase of the colors. In one aspect of the there is provided a method of generating spin currents in a photoconductor material comprising producing a first coherent light beam having a first frequency &ohgr;1 and a second coherent light beam having a frequency twice the first frequency 2&ohgr;1, polarizing the first and second coherent light beams to have a preselected polarization with respect to each other, and simultaneously irradiating a selected region of the photoconductor material with the first coherent light beam and the second coherent light beam to generate a spin current in the photoconductor.
    Type: Application
    Filed: March 22, 2002
    Publication date: September 26, 2002
    Inventors: Ravi D.R. Bhat, John Edward Sipe, Henry Martin Van Driel
  • Publication number: 20020131141
    Abstract: An electro-optical device is provided having a structure which, in particular, allows the device to be made smaller and thinner, and the heat-dissipation capability to be increased in order to prevent overheating. A positioning section which accommodates an opposing substrate, and which contacts an edge of an element substrate is provided in a case member accommodating an electro-optical panel which consists of the opposing substrate and the element substrate.
    Type: Application
    Filed: May 22, 2002
    Publication date: September 19, 2002
    Applicant: Seiko Epson Corporation
    Inventor: Hiromi Saitoh
  • Publication number: 20020118434
    Abstract: The present invention provides an improved switchable interleaved channel separator device. The switchable interleaved channel separator device utilizes a reflective interferometer and one single-segment switchable polarization rotator. The reflective interferometer causes signal light paths to be reflected back upon one another so as to realize an overall reduction in size. This path reflection also enables the capability of providing optical couplings predominantly or wholly at a single side or at adjacent sides of the device.
    Type: Application
    Filed: February 23, 2001
    Publication date: August 29, 2002
    Inventor: Simon Xiaofan Cao
  • Publication number: 20020114055
    Abstract: This relates to an electro-modulating device (10) for modulating light from a light source, as part of an opto-electronic communication network. The electro-modulating device (10) has a modulating medium (16) for modulating light passing therethrough by varying an electric field applied across the modulating medium (16), an optical input-output surface (21), a light reflector (28), and electrodes (15, 17) for applying the varying electric field across the modulating medium (16). The input-output surface (21), the medium (16) and the reflector (28) are arranged so that light enters the medium (16) through the input-output surface (21), travels through the medium (16) towards the reflector (28), is reflected by the reflector (28) to travel back through the medium (16) towards the input-output surface (21), and exits the medium (16) through the input-output surface (21).
    Type: Application
    Filed: January 14, 2002
    Publication date: August 22, 2002
    Applicant: Agilent Technologies, Inc.
    Inventor: Christopher Anthony Park
  • Patent number: 6437900
    Abstract: Transflective display device having a transflector (10) which is switchable between a transparent state and a mirror-like state. Preferably, a metal hydride optical switch is used as the transflector.
    Type: Grant
    Filed: April 19, 2000
    Date of Patent: August 20, 2002
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Hugo J. Cornelissen, Martin Ouwerkerk, Peter A. Duine
  • Patent number: 6426816
    Abstract: The inventive filter forms a four filtering stage device from two filtering stages and a reflective stage. This greatly reduces the noise level in a WDM signal, wherein the signal is one of the odd channels and the even channels, while the noise is present on the other of the odd channels and the even channels. The first stage separates the WDM signal and noise into their polarization components, rotates the components of one of the signal and the noise, and recombines the components of the signal, while blocking a portion of the noise. This output is passed to the second stage which repeats the operation of the first stage. The output of the second stage is then reflected by the reflecting stage back to the second stage, and subsequently the first stage, for processing in reverse order. The inventive filter, via the mirror in the reflecting stage, reduce dispersion of the light during processing.
    Type: Grant
    Filed: July 12, 2000
    Date of Patent: July 30, 2002
    Assignee: Chorum Technologies, LP
    Inventors: Kuang-Yi Wu, Charles Wong, Jian-Yu Liu, Ye Li
  • Publication number: 20020093718
    Abstract: The present invention provides a polarization separation element comprising a first array of prisms having a wedge-shaped cross-section, and a second array of prisms also having a wedge-shaped cross section. One of the prism arrays is an array of birefringent prisms.
    Type: Application
    Filed: October 11, 2001
    Publication date: July 18, 2002
    Inventors: Jason Kempton Slack, Marina Vladimirovna Khazova, Tamotsu Takatsuka, Keisuke Mitani, Kazuhiro Inoko, Graham John Woodgate, Masaharu Hara, Grant Bourhill, Emma Walton
  • Patent number: 6411420
    Abstract: Polarization inversion domains 2 are irregularly formed in a ferroelectric substrate 3 constituting an electro-optical element 1 at least in the propagation direction of a light beam A. An A.C. current signal is applied between electrodes 4 and 5. It is thereby arranged to disturb the phase of each of the light rays constituting a light beam whose coherent characteristic is high, such as a laser light or the like, and thereby to easily obtain the light beam whose coherent characteristic has been decreased.
    Type: Grant
    Filed: March 14, 2000
    Date of Patent: June 25, 2002
    Assignee: Sony Corporation
    Inventors: Masahiro Yamada, Toru Domuki, Hitoshi Tamada
  • Publication number: 20020075549
    Abstract: The present invention relates to a modulated light source (10), in particular for use as part of an opto-electronic communication network. The modulated light source (10) has a laser (12) and an external electro-optic modulator (16) for modulating the intensity of light produced by the laser (12). A temperature sensor (30) senses the temperature of the laser (12) and the modulator (16). A control circuit connected to the temperature sensor (30) adjusts the bias on the modulator (16) so that the band edge of the modulator follows the changes in wavelength of the laser (12) as the laser (12) warms up during operation. This avoids the need for a cooling element to keep the temperature of the laser (12) constant.
    Type: Application
    Filed: May 16, 2001
    Publication date: June 20, 2002
    Inventors: Richard Mark Ash, Christopher Anthony Park, Andrew Thomas Harker
  • Patent number: 6404538
    Abstract: An optical modulator is provided to control the intensity of a transmitted or reflected light. In a transmission mode, a separator splits arbitrarily polarized light into two polarization rays and one is made to travel a separate path from the other. A recombiner causes the two rays to recombine at an output unless an electro-optic phase retarder changes the polarization of the two rays, in which case, both of them miss the output by an amount which is a function of the voltage on the retarder. A normally-off version with low polarization mode dispersion is obtained by changing the orientation of the recombiner. A normally-on version with low polarization mode dispersion is obtained with a passive polarization direction rotator. Similar results can be obtained in a reflection mode where the input and output are on the same side of the modulator. Versions using a GRIN lens are particularly suited to modulation of light out of and back into fiber-optic cables.
    Type: Grant
    Filed: October 24, 2000
    Date of Patent: June 11, 2002
    Assignee: Corning Applied Technologies Corporation
    Inventors: Qiushui Chen, Gary Y. Wang, Paul Melman, Kevin Zou, Hua Jiang, Run Zhang, Jing Zhao, Dean Tsang, Feiling Wang
  • Patent number: 6404537
    Abstract: A polarization transformer includes at least one plate of transparent polycrystalline material which has an optical axis oriented perpendicular to a propagation direction of incident radiation having a first polarization state. The plate includes electrodes for applying an electric field across a plane of the plate perpendicular to the propagation direction so as to provide controlled phase change such that the polarization of radiation transmitted through the polarization transformer is transformed from the first polarization state to a second polarization state. The plate in a preferred embodiment comprises a ferroelectric complex oxide such as lead lanthanum zirconate titanate (PLZT) material. Such a material provides devices that have very fast response (on the order of microseconds) and low insertion loss.
    Type: Grant
    Filed: March 6, 2000
    Date of Patent: June 11, 2002
    Assignee: Corning Applied Technologies Corporation
    Inventors: Paul Melman, Yingyin Zou, Qiushui Chen
  • Publication number: 20020060833
    Abstract: An electro-optical device comprising, a first board and a second board superposed on each other; a seal 6 for bonding the first board and the second board at the periphery of a display area; a plurality of connection terminals 71 provided on an overhang of the first board which extends from the second board; and a plurality of connection wires 70 provided on the first board and interconnecting the display area and the plurality of connection terminals 71. The distance between adjacent connection wires 119b is set to be smaller inside the seal 6 than outside the seal 6. This prevents the occurrence of corrosion in the connection wires 70 lying outside the seal 6, and shortens the distance between adjacent connection wires 70 lying inside the seal 6, thereby reducing the overall size of the liquid crystal device.
    Type: Application
    Filed: September 21, 2001
    Publication date: May 23, 2002
    Inventor: Yoshio Yamaguchi
  • Publication number: 20020044331
    Abstract: Edge busbars on a substantial perimeter of an electrochromic device are disclosed having electrical paths wrapping over the perimeter edge. Internal busbars interior from the perimeter are disclosed which lower the conductivity of the conductive layer of an electrochromic device. Signals supplied to the busbars to control the electrochromic device are controlled by a switching power supply that allows the maintaining of the color of the electrochromic device without application of continuous power.
    Type: Application
    Filed: September 20, 2001
    Publication date: April 18, 2002
    Inventors: Anoop Agrawal, Juan Carlos Lopez Tonazzi, Robert LeCompte, John Cronin, Steve Kennedy, Kevin McCarthy, Matthew Denesuk, Gimtong Teowee