With Birefringent Element Patents (Class 359/256)
  • Patent number: 6728020
    Abstract: Platelike first transparent members 321 and platelike second transparent members 322 are prepared. Each first transparent member has substantially parallel first and second surfaces (film forming surfaces). A polarization splitting film 331 is formed on the first film forming surface. A reflecting film 332 is formed on the second film forming surface. The films are not formed on the surfaces of the second transparent members 322. A plurality of the first transparent members 321 and a plurality of the second transparent members 322 are adhered alternately. A block is cut from the so-adhered transparent members at a prescribed angle to the surfaces and the cut surfaces thereof are polished to obtain a polarization beam splitter array 320.
    Type: Grant
    Filed: March 6, 2002
    Date of Patent: April 27, 2004
    Assignee: Seiko Epson Corporation
    Inventor: Yajima Akitaka
  • Patent number: 6728021
    Abstract: High precision optical components, for example CaF2 lenses in lithographic systems for the production of integrated circuits, often suffer from stress induced birefringence and other imperfections. For altering the optical properties in a confined region of the optical component, the latter is exposed to a beam of ions having an energy preferably in the order 100 MeV/u. This results in a modification of the optical properties due to an interaction of the ions with the surrounding medium the optical component consists of. By carefully choosing the parameters of the process, it is possible to alter the refractive index or the mechanical stress distribution or other optical properties within a confined region of this medium.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: April 27, 2004
    Assignee: Carl Zeiss SMT AG
    Inventors: Alexander Kohl, Hubert Holderer
  • Patent number: 6683710
    Abstract: An optical system includes multiple cubic crystalline optical elements aligned along a common optical axis and having their crystal lattices oriented with respect to each other to minimize the effects of intrinsic birefringence and produce a system with reduced retardance. The optical system may be a refractive or catadioptric system having a high numerical aperture and using light with a wavelength at or below 248 nanometers. The net retardance of the system is less than the sum of the retardance contributions of the respective optical elements as the elements are oriented such that the intrinsic birefringences of the individual elements cancel each other out. In one embodiment, two [110] cubic crystalline optical elements are clocked with respect to one another and used in conjunction with a [100] cubic crystalline optical element to reduce retardance.
    Type: Grant
    Filed: February 7, 2002
    Date of Patent: January 27, 2004
    Assignee: Optical Research Associates
    Inventors: Jeffrey M. Hoffman, James P. McGuire
  • Publication number: 20040001244
    Abstract: An optical system includes multiple cubic crystalline optical elements aligned along a common optical axis and having their crystal lattices oriented with respect to each other to minimize the effects of intrinsic birefringence and produce a system with reduced retardance. The optical system may be a refractive or catadioptric system having a high numerical aperture and using light with a wavelength at or below 248 nanometers. The net retardance of the system is less than the sum of the retardance contributions of the respective optical elements as the elements are oriented such that the intrinsic birefringences of the individual elements cancel each other out. In one embodiment, two [110] cubic crystalline optical elements are clocked with respect to one another and used in conjunction with a [100] cubic crystalline optical element to reduce retardance.
    Type: Application
    Filed: February 20, 2003
    Publication date: January 1, 2004
    Applicant: Optical Research Associates
    Inventors: Jeffrey M. Hoffman, James P. McGuire
  • 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: 6650456
    Abstract: The present invention provides a device, a method of making the device, and a system incorporating the same. In one embodiment, the device includes a substrate that has first and second opposing surfaces and first and second thicknesses, wherein the second thickness is less than the first thickness, and the first surface is substantially planar. The device further includes a conductive trace having an input end and an output end and located over the first surface of the substrate, wherein at least one of the input end or output end is aligned with the second substrate thickness.
    Type: Grant
    Filed: April 11, 2002
    Date of Patent: November 18, 2003
    Assignee: TriQuint Technology Holding Co.
    Inventors: Frank F. Judd, Yongqiang Shi
  • Patent number: 6639707
    Abstract: A low dispersion comb filter or interleaver comprises a first birefringent element assembly having at least one birefringent element and a second birefringent element assembly having at least one other birefringent element. The first birefringent element assembly and the second birefringent element assembly are configured so as to cooperate with one another in a manner which mitigates dispersion of the interleaver. By aligning the polarization directions of the odd channels and the even channels so as to be parallel with respect to one another prior to entering the second birefringent element assembly, zero or nearly zero dispersion is obtained simultaneously for both the odd and even channels.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: October 28, 2003
    Assignee: Cirvine Corporation
    Inventor: Bin Zhao
  • Patent number: 6628449
    Abstract: A low dispersion comb filter or interleaver comprises a first birefringent element assembly having at least one birefringent element and a second birefringent element assembly having at least one other birefringent element. The first birefringent element assembly and the second birefringent element assembly are configured so as to cooperate with one another in a manner which mitigates dispersion of the interleaver. By aligning the polarization directions of the odd channels and the even channels so as to be parallel with respect to one another prior to entering the second birefringent element assembly, zero or nearly zero dispersion is obtained simultaneously for both the odd and even channels.
    Type: Grant
    Filed: June 25, 2001
    Date of Patent: September 30, 2003
    Assignee: Cirvine Corporation
    Inventor: Bin Zhao
  • Publication number: 20030137712
    Abstract: An improved electrochromic device comprising a substrate and a first conductive layer located on the transparent substrate. An ion storage layer is located on the first conductive layer. An electrolyte layer is located on the ion storage layer with an active layer being located on the electrolyte layer.
    Type: Application
    Filed: January 31, 2003
    Publication date: July 24, 2003
    Applicant: Eclipse Energy Systems, Inc.
    Inventors: Raymond T. Westfall, Nikolai Kislov
  • Patent number: 6570711
    Abstract: A conventional interleaver, based on a stack of waveplates, relies on the orientation and the birefringence of the waveplates to differentiate the polarizations of one set of channels from another, so that the one set of channels can be separated from the other. The present invention relates to a virtual waveplate that is used to replace a birefringent waveplate. A virtual waveplate imposes a phase delay between the extraordinary ray and the ordinary ray by separating one from the other and differentiating the actual path lengths taken thereby, before recombining them. An interleaver constructed with the virtual waveplates of the present invention can be substantially a-thermal and potentially chromatic dispersion free.
    Type: Grant
    Filed: July 31, 2001
    Date of Patent: May 27, 2003
    Assignee: JDS Uniphase Inc.
    Inventor: Thomas Ducellier
  • Patent number: 6542204
    Abstract: A display optical system has an illumination optical system for emitting illumination light, a plurality of reflection-type display devices, a projection optical system, and a plane-parallel mirror. The reflection-type display devices individually modulate the illumination light emitted from the illumination optical system and reflect the illumination light thus modulated as projection light. The projection optical system projects the projection light and has at least one optical element included therein arranged so as to be decentered with respect to the other optical elements included therein.
    Type: Grant
    Filed: January 28, 2000
    Date of Patent: April 1, 2003
    Assignee: Minolta Co., Ltd.
    Inventors: Soh Ohzawa, Mituaki Shimo
  • Patent number: 6528339
    Abstract: A method of imparting birefringence in a III-V compound semiconductor for sustaining the non linear optical process of second harmonic generation, a birefringent III-V compound semiconductor, and a product of the process are described.
    Type: Grant
    Filed: October 1, 2001
    Date of Patent: March 4, 2003
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Jonathan T. Goldstein
  • Patent number: 6529307
    Abstract: A method and apparatus for achieving dynamic intensity modulation of the channels in a wavelength-division multiplexed optical communication system is presented. Wavelengths are spatially separated into a plurality of channels, the polarization states of which are individually modulated. The channels can be combined or filtered by polarization states to achieve the desired intensity in the output signal. An exemplary embodiment includes at least a polarization modulator, a birefringent wedge, a lens, and a dispersive element (e.g., diffraction grating) arranged in various order. Each segment of the polarization modulator can be made to rotate the polarization direction of an incident channel by a specified angle. A half-wave plate may be inserted between the second dispersive element and the second birefringent wedge to eliminate polarization-dependent loss. Optionally, a parallel birefringent plate may be inserted after the second birefringent wedge to reduce polarization mode dispersion.
    Type: Grant
    Filed: June 4, 2001
    Date of Patent: March 4, 2003
    Assignee: Avanex Corporation
    Inventors: Song Peng, Ming Li
  • Publication number: 20030039019
    Abstract: A tuneable optical filter having a variable wavelength transmittance. The filter comprises a pre-polariser, a post-polariser and a birefringent plate positioned between the pre-polariser and the post-polariser. A twisted nematic liquid crystal cell (TN LCD) is positioned between the pre-polariser and the post-polariser, the TN LCD being controlled, in use, to tune the filter. A quarter wave plate is positioned adjacent the birefringent plate.
    Type: Application
    Filed: September 19, 2002
    Publication date: February 27, 2003
    Inventors: Timothy Large, Mary New, Allan Carmichael
  • Patent number: 6522456
    Abstract: An apparatus and method for filtering an optical input is disclosed. In an illustrative embodiment, an optical input is split into polarization components along separate paths. The polarization components are then fed into a first electro-optic device that includes a set of electrodes across which a voltage is applied to adjust a wavelength transmission characteristic of the device. A section of the first device positioned between the electrodes preferably has a birefringence that is adjusted depending on the voltage applied across the electrodes. The adjusted components of the optical input are thereafter combined to produce an optical output. Accordingly, the optical input can be attenuated based on the voltage applied to electrodes of the first electro-optic device.
    Type: Grant
    Filed: May 4, 2001
    Date of Patent: February 18, 2003
    Assignees: Corning Applied Technologies, Inc., Corning Incorporated
    Inventors: Qiushui Chen, Hua Jiang, Yingyin Zou, Dean Tsang, Paul Melman, Feiling Wang, Guanghai Jin, Jing Zhao
  • Patent number: 6515786
    Abstract: An optical device comprises a first birefringent crystal having a first length, a second birefringent crystal having a second length, and a dynamic polarization rotator. An optical signal propagating through the first and second birefringent crystals has an effective optical path length based, at least in part, upon the first length of the first birefringent crystal and the second length of the second birefringent crystal. The dynamic polarization rotator adjusts the effective optical path length of the optical signal in response to a control signal.
    Type: Grant
    Filed: August 3, 2001
    Date of Patent: February 4, 2003
    Assignee: Chorum Technologies LP
    Inventors: Tiejun Xia, Chi-Hao Cheng, Shuxin Li, Jian-Yu Liu, Kuang-Yi Wu
  • Patent number: 6515785
    Abstract: Optical devices using reflective polarizers and, in particular, diffusely reflective polarizers are provided. Many of the optical devices utilize the diffusely reflecting and specularly transmitting properties of diffusely reflecting polarizers to enhance their optical characteristics. The optical devices include a lighting system which uses a reflector formed from a diffusely reflecting polarizer attached to a specular reflector. Another optical device is a display apparatus which uses a diffusely reflecting polarizer layer in combination with a turning lens which folds shallow angle light toward a light modulating layer. Other optical devices exploit the depolarizing characteristics of a diffusely reflecting polaizer when reflecting light. Still other optical devices use diffusely reflecting polarizers to recycle light and improve display illumination.
    Type: Grant
    Filed: April 22, 1999
    Date of Patent: February 4, 2003
    Assignee: 3M Innovative Properties Company
    Inventors: Sanford Cobb, Jr., David L. Wortman
  • Patent number: 6511186
    Abstract: An image projection system includes an image generator, a screen and a focus and aim component. The focus and aim component receives modulated light from the image generator and focuses and deflects the light as a function of a position on the screen. The component consists of an array of lenslets with wedge. The wedge or prism refracts the light and the lens focuses the light. As a result, the optics are selectively tailored to provide a clear image over the entire field of view, even in systems compact in depth that would otherwise rely on a short focal length lens. Acute incidence angles at the periphery of the screen are handled by TIR Fresnel lens elements or by diffractive elements. The focus and aim capability is alternatively provided by holographic elements in a holographic array.
    Type: Grant
    Filed: July 7, 2000
    Date of Patent: January 28, 2003
    Assignee: Sarnoff Corporation
    Inventors: Herschel Clement Burstyn, Michael J. Lurie
  • Publication number: 20030016432
    Abstract: The present invention relates to a tunable optical filter having a variable wavelength characteristic of transmittance. The tunable optical filter includes first and second polarizers each having a transmission axis determining a polarization axis of transmitted polarized light, a birefringent element having an optic axis determining a phase difference given between two orthogonal components of transmitted polarized light, and a Faraday rotator for giving a variable Faraday rotation angle to transmitted polarized light. The birefringent element and the Faraday rotator are provided between the first and second polarizers.
    Type: Application
    Filed: September 13, 2002
    Publication date: January 23, 2003
    Applicant: FUJITSU LIMITED
    Inventors: Takafumi Terahara, Nobuhiro Fukushima
  • Publication number: 20030007232
    Abstract: A low dispersion comb filter or interleaver comprises a first birefringent element assembly having at least one birefringent element and a second birefringent element assembly having at least one other birefringent element. The first birefringent element assembly and the second birefringent element assembly are configured so as to cooperate with one another in a manner which mitigates dispersion of the interleaver. By aligning the polarization directions of the odd channels and the even channels so as to be parallel with respect to one another prior to entering the second birefringent element assembly, zero or nearly zero dispersion is obtained simultaneously for both the odd and even channels.
    Type: Application
    Filed: November 30, 2001
    Publication date: January 9, 2003
    Inventor: Bin Zhao
  • Patent number: 6504642
    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: January 7, 2003
    Assignee: Spectraswitch, Inc.
    Inventors: Richard Albert, Arne Erstling, Desmond L. Seekola, Brent Bergner, Michael Knotz
  • Patent number: 6491391
    Abstract: An electro-active spectacle lens is disclosed. The disclosed lens includes a first lens optic. The disclosed lens also includes a first electro-active zone positioned in a cooperative relationship with the first lens optic. In certain embodiments, the electro-active lens includes a range finder positioned in a cooperative relationship with the electro-active lens.
    Type: Grant
    Filed: June 23, 2000
    Date of Patent: December 10, 2002
    Assignee: E-Vision LLC
    Inventors: Ronald D. Blum, Dwight P. Dustin, Youval Katzman, Israel Grossinger, Uzi Efron, Dan Katzman
  • Patent number: 6493139
    Abstract: The present invention relates to optical switches in which switching occurs by changing the rotation of the plane of polarization by application of an externally applied control signal, particularly to magneto-optical switches controlling the port by which light emerges from the switch by externally-applied magnetic fields. The switches of the present invention function for randomly polarized input light, producing similarly randomly polarized light at the appropriate output port. Specific embodiments relate to 1×2 and 1×4 switches in both single pass and dual pass embodiments. Single pass embodiments are switches in which light passes through the optical components in one direction emerging at the appropriate output port depending on the desired switching. Dual pass embodiments are switches in which the light makes a forward and reverse traverse of the switch with total reflection. Dual pass switches typically reduce crosstalk without increasing the size of the switch.
    Type: Grant
    Filed: March 16, 2001
    Date of Patent: December 10, 2002
    Inventors: Hongdu Liu, Daxin Liu, Shizhuo Yin, Lee Lisheng Huang
  • Patent number: 6486997
    Abstract: An optical imaging system including a wide-angle Cartesian polarizing beam splitter, light valve illumination optics having an f/#≦2.5, and at least one reflective light valve. The Cartesian polarizing beam splitter (PBS) has a structural orientation defining fixed polarization axes. The use of a Cartesian PBS allows the development of systems using curved PBS that provide higher light output and/or replace or augment other optical components. By recognizing and advantageously applying properties of wide-angle Cartesian polarizers, the present invention discloses a high-efficiency optical imaging system capable of functioning at f/#'s equal to or below f/2.5 while maintaining a contrast ratio of at least 100 to 1, or, more preferably, 150 to 1 in a projection system configuration.
    Type: Grant
    Filed: May 17, 1999
    Date of Patent: November 26, 2002
    Assignee: 3M Innovative Properties Company
    Inventors: Charles L. Bruzzone, David J. W. Aastuen, Roger J. Strharsky, Stephen K. Eckhardt, Michael F. Weber, Gary T. Boyd
  • Publication number: 20020171905
    Abstract: The present invention relates to optical switches in which switching occurs by changing the rotation of the plane of polarization by means of an externally applied control signal, particularly to magneto-optical switches controlling the port by which light emerges from the switch by externally-applied magnetic fields. The switches of the present invention function for randomly polarized input light, producing similarly randomly polarized light at the appropriate output port. Specific embodiments relate to 1×2 and 1×4 switches in both single pass and dual pass embodiments. Single pass embodiments are switches in which light passes through the optical components in one direction emerging at the appropriate output port depending on the desired switching. Dual pass embodiments are switches in which the light makes a forward and reverse traverse of the switch with total reflection. Dual pass switches typically reduce crosstalk without increasing the size of the switch.
    Type: Application
    Filed: March 16, 2001
    Publication date: November 21, 2002
    Inventors: Hongdu Liu, Daxin Liu, Shizhuo Yin, Lee Lisheng Huang
  • Publication number: 20020163707
    Abstract: An apparatus and method for filtering an optical input is disclosed. In an illustrative embodiment, an optical input is split into polarization components along separate paths. The polarization components are then fed into a first electro-optic device that includes a set of electrodes across which a voltage is applied to adjust a wavelength transmission characteristic of the device. A section of the first device positioned between the electrodes preferably has a birefringence that is adjusted depending on the voltage applied across the electrodes. The adjusted components of the optical input are thereafter combined to produce an optical output. Accordingly, the optical input can be attenuated based on the voltage applied to electrodes of the first electro-optic device.
    Type: Application
    Filed: May 4, 2001
    Publication date: November 7, 2002
    Applicant: Corning Applied Technologies, Inc.
    Inventors: Qiushui Chen, Hua Jiang, Yingyin Zou, Dean Tsang, Paul Melman, Feiling Wang, Guanghai Jin, Jing Zhao
  • Patent number: 6476967
    Abstract: The invention provides a compact optical circulator with three ports positioning between a dual-core collimator and a single-core collimator. The inventive circulator has a propagation director to couple a light from the dual-core collimator to one port of the circulator and another light form the other port of the circulator to the dual-core collimator. The invention further provides a compact optical circulator with three ports having a reflective compensator. The reflective compensator compensates the optical path length of two polarized beams. Furthermore, the invention eliminates the polarization mode dispersion by utilizing a reflective compensator. As well, the inventive circulator forgoes use of the reciprocal polarizing-rotating unit, thus reducing production costs.
    Type: Grant
    Filed: November 1, 2001
    Date of Patent: November 5, 2002
    Assignee: Industrial Technology Research Institute
    Inventors: Chieh Hu, Chen-Bin Huang, Chin-Lan Liao
  • 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
  • Patent number: 6426821
    Abstract: Apparatuses, methods, and systems are disclosed that provide for simultaneously upconverting electrical signals carrying information at electric frequencies onto optical subcarrier lightwave frequencies that are greater and less than the carrier frequency of the lightwave onto which the electrical frequencies were upconverted. The upconversion of the electrical signals can be performed with or without suppression of the optical carrier frequency.
    Type: Grant
    Filed: April 7, 2000
    Date of Patent: July 30, 2002
    Assignee: Corvis Corporation
    Inventors: Alistair J. Price, Thomas D. Stephens
  • Publication number: 20020080462
    Abstract: A controllable phase plate has numerous domains that are randomized as to the orientation of their birefringence and can be used in a power limiting control to produces an electrically controllable diffraction pattern having a portion, especially the zero mode axial spot of the pattern, that is directed onto an output aperture such as a pinhole or an optical fiber end. Controlling the phase plate produces an interference peak or null (or an intermediate level) of light, coupled into the output aperture. The phase plate preferably comprises a liquid crystal with controllable birefringence. The domains have paired orthogonal orientations, which is a condition that is met in randomized domains. The paired orthogonal orientations make the device polarization insensitive. In a controllable attenuating device, collimating lenses are placed before and after the phase plate along a beam path to focus a clear interference pattern on a screen containing the output aperture.
    Type: Application
    Filed: November 27, 2001
    Publication date: June 27, 2002
    Inventors: Jayantilal S. Patel, Zhizhong Zhuang
  • Publication number: 20020080467
    Abstract: A polarization mode dispersion generator for generating polarization mode dispersion (“PMD”) spectra is provided. The generator includes a plurality of birefringent stages, each stage including a differential group delay (“DGD”) element and a phase-shifting element. The generator is capable of inducing an amount of polarization mode-mixing between at least one adjacent pair of stages. The shape of a PMD spectrum can be preserved while frequency shifting the spectrum in either direction. Alternatively, the shape of the PMD spectrum can be changed without frequency shifting.
    Type: Application
    Filed: December 7, 2001
    Publication date: June 27, 2002
    Applicant: Yafo Networks, Inc.
    Inventor: Jay N. Damask
  • Patent number: 6389185
    Abstract: An optical fiber that transforms light of undesired polarization into light of desired polarization. In principle, the signal power of the non-preferred polarization is transformed into signal power of the preferred polarization, thereby actually transforming the polarization. The fiber can have a circular end for input of light having randomly phased polarization, and an elongated end for output of light having a single principal orientation component. A generally smooth transition from the circular end to the elongated end causes substantially all the light entering the fiber to exit from the fiber without losing light due to reflection or radiation. Alternatively, the fiber can have a lobed end, for input of light having first and second mutually orthogonal polarization components, and an elongated end, for output of light having a single principal orientation component. Alternatively, the fiber can be a combination of the two forms described above.
    Type: Grant
    Filed: January 8, 2001
    Date of Patent: May 14, 2002
    Assignee: Lockheed Martin Corporation
    Inventors: William H. Meise, Harvey L. Wagner, Thomas W. Karras
  • Patent number: 6384972
    Abstract: A projection display is used to process a light beam that includes first, second and third color components and that is to be provided to a projection lens. The projection display includes a dichroic beam splitter which separates the first color component from the second and third color components. A first polarization beam splitter prism cooperates with a first reflective light valve to process the first color component. A second polarization beam splitter prism cooperates with second and third reflective light valves to process the second and third color components. A third polarization beam splitter prism is disposed so as to direct the processed color components from the first and second polarization beam splitter prisms to the projection lens.
    Type: Grant
    Filed: June 13, 2001
    Date of Patent: May 7, 2002
    Assignee: Prokia Technology Co., Ltd.
    Inventor: Fu-Ming Chuang
  • Patent number: 6384956
    Abstract: A reset-free polarization controller is presented for maintaining the polarization of an incident optical signal at a fixed and known value. At least 3 controllable quarter-wavelength plates are connected in cascade to an incident optical source having a variable polarization. Each quarter-wavelength plates varies the orientation of phase retardation along the optical wavepath. The dynamic realignment of the cascaded quarter-wavelength plates with respect to the varying input polarization maintains the polarization of the output optical signal at a fixed and known value.
    Type: Grant
    Filed: February 2, 2000
    Date of Patent: May 7, 2002
    Assignee: Lucent Technologies Inc.
    Inventor: William Shieh
  • Publication number: 20020051277
    Abstract: A low dispersion comb filter or interleaver comprises a first birefringent element assembly having at least one birefringent element and a second birefringent element assembly having at least one other birefringent element. The first birefringent element assembly and the second birefringent element assembly are configured so as to cooperate with one another in a manner which mitigates dispersion of the interleaver. By aligning the polarization directions of the odd channels and the even channels so as to be parallel with respect to one another prior to entering the second birefringent element assembly, zero or nearly zero dispersion is obtained simultaneously for both the odd and even channels.
    Type: Application
    Filed: June 25, 2001
    Publication date: May 2, 2002
    Inventor: Bin Zhao
  • Publication number: 20020048074
    Abstract: An optical spectrum slicer capable of converting and outputting discontinuous spectrum lights having spectral components at a desired wavelength spacing from a broad band continuous spectrum light, with a simple constitution and at a reduced cost, the slider comprising a birefringent device having two polarization axes each orthogonal to an optical axis (z) and linear polarizers disposed at the light incident end and the light emission end thereof, with the direction of polarization being inclined by about 45° relative to each of polarization axes, and a heat generator for controlling the temperature of the birefringent device thereby variably controlling each of wavelengths while maintaining the wavelength spacing of the discontinuous spectrum lights.
    Type: Application
    Filed: July 16, 2001
    Publication date: April 25, 2002
    Applicant: MORITEX CORPORATION
    Inventors: Yoshihiro Ohtsuka, Koji Horio, Syumei Tokuyama
  • Patent number: 6373614
    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: Grant
    Filed: August 31, 2000
    Date of Patent: April 16, 2002
    Assignee: Cambridge Research Instrumentation Inc.
    Inventor: Peter J. Miller
  • Patent number: 6331910
    Abstract: In an arrangement and a method for electrically controlling the intensity of non-polarized light, a polarizing beam splitter is acted upon by the light to be controlled via an input face such that the light is split into two polarized light bundles that are orthogonal with respect to each other. Provision is made that a first reflecting device is configured for the reflection of at least one of the polarized light bundles, so that both polarized light bundles run in parallel. At least one electro-optical element is provided in a path of the parallel running polarized light bundles. The polarization is changed as a function of the supplied control voltage. Also provided is a second reflecting device for reflecting the light bundles in the opposite direction.
    Type: Grant
    Filed: January 19, 2000
    Date of Patent: December 18, 2001
    Assignee: Deutsche Telekom AG
    Inventors: Wolfgang Dultz, Leonid Beresnev, Galina Patrusheva, Wolfgang Haase
  • Patent number: 6321023
    Abstract: A computer-readable signal bearing medium (10) has components (11, 21, 31) which act via a data processor (86) in an imaging system having an acoustic energy source (81) and a birefringent detector (84, 70) to record first data (14) from a first portion (61) of an object (60), the first portion attenuating first acoustic energy (12) at least part way to a first attenuation maximum (13, 43) along a first acousto-optic response (41) of the birefringent detector; to record second data (24) from a second portion (62) of the object, the second portion attenuating second acoustic energy (22) at least part way to a second attenuation maximum (23, 53) along a second acousto-optic response (51) of the birefringent detector; combines the data (32), and outputs a result.
    Type: Grant
    Filed: June 20, 2000
    Date of Patent: November 20, 2001
    Inventors: Honghui Wang, Jaswinder S. Sandhu, Witold J. Popek
  • Patent number: 6317250
    Abstract: A method and apparatus for optically isolating multiple core optical fibers while at the same time substantially reducing polarization mode dispersion, is disclosed. A multiple core fiber is optically coupled to optical birefringent elements, reciprocal and non-reciprocal rotators, and through a lens assembly to a multiple core optical fiber output.
    Type: Grant
    Filed: September 12, 2000
    Date of Patent: November 13, 2001
    Assignee: E-Tek Dynamics, Inc.
    Inventors: Kejian Guan, Kok Wai Chang
  • Patent number: 6310713
    Abstract: An illumination system and display are disclosed that include a light for providing light, a polarizing beam splitter (PBS) having a first surface that receives the light from the backlight. The PBS passes a first polarization of the received light to a curved mirror located at a second PBS face, which second PBS face is opposite the first PBS face. The curvature of the mirror provides the optical power necessary for proper imaging, while limiting the reflecting area of the mirror provides an aperture stop that determines the numerical aperture of the optical system. The display also includes a quarter wave plate and a spatial light modulator (SLM). The quarter wave plate is located between the PBS and mirror and changes the first polarization of light, directed from the PBS to the mirror, to a second polarization which is reflected from the mirror back to the PBS.
    Type: Grant
    Filed: April 7, 1997
    Date of Patent: October 30, 2001
    Assignee: International Business Machines Corporation
    Inventors: Fuad Elias Doany, Rama Nand Singh
  • Publication number: 20010024314
    Abstract: The present invention provides a method for calculating the birefringence of an optical element and selecting the direction of minimum birefringence in the optical element. A material for manufacturing the optical element is a fluoride single crystal with a birefringence value that is reduced compared to conventional materials. The fluoride single crystal is cut from a fluoride single crystal ingot obtained by crystal growth so that the {111} crystal planes are two parallel planes, after which the optical performance is improved by subjecting this material to a heat treatment. The birefringence of the optical element is calculated by converting known piezo-optical constants in a specified three-dimensional orthogonal coordinate system for the optical material into piezo-optical constants in an arbitrary three-dimensional orthogonal coordinate system.
    Type: Application
    Filed: December 27, 2000
    Publication date: September 27, 2001
    Applicant: Nikon Corporation
    Inventors: Shigeru Sakuma, Shuuichi Takano
  • Patent number: 6285473
    Abstract: The present invention,is directed to an optical space switch accommodating a plurality of input light paths and output light paths. The optical space switch comprises a plurality of polarization control optical switches, each consisting essentially of: polarization control means having elements, one for each input light path, for rotating through 90° the polarizing direction of light information incident from each input light path or otherwise retaining the polarizing direction thereof for output; and a light path routing element for routing the light path for the light information output from the polarization control means in accordance with the polarizing direction of the light information. These polarization control optical switches are arranged in a matrix pattern or coupled in cascade to implement a polarization control optical space switch.
    Type: Grant
    Filed: August 2, 2000
    Date of Patent: September 4, 2001
    Assignee: Fujitsu Limited
    Inventors: Tetsuya Nishi, Takuji Maeda, Satoshi Kuroyanagi, Tsuyoshi Yamamoto
  • Patent number: 6236507
    Abstract: The invention features systems and methods for generating optical beams having substantially orthogonal polarizations for use in distance measuring interferometry. In one embodiment, the invention features a system including a source which during operation generates two nonparallel propagating source beams; and a retarder element positioned to receive the two nonparallel propagating source beams and convert them into two nonparallel propagating output beams that are polarized substantially orthogonal to one another. The system can further include a birefringent prism positioned to receive the two nonparallel propagating output beams and produce two parallel output beams.
    Type: Grant
    Filed: April 17, 1998
    Date of Patent: May 22, 2001
    Assignee: Zygo Corporation
    Inventors: Henry A. Hill, Peter de Groot
  • Patent number: 6204952
    Abstract: A Bragg modulator modulates the intensity of a light beam, in particular of a laser beam. The Bragg modulator includes an electro-optic crystal wafer with a rectangular top face, in particular a lithium niobate or lithium tantalate crystal wafer, and a grid structure with normal zones and inversion zones. In the inversion zones, the direction of the spontaneous polarization is inverted compared to a normal direction in the normal zones. Electrodes are disposed on the top and bottom faces of the crystal wafer to generate an electric field therebetween. The grid structure is spaced apart from the front, back and side faces of the crystal wafer and is completely covered by the electrodes. The inversion zones of the grid structure are disposed at the Bragg angle (&THgr;B) relative to the direction of a light beam entering the front face of the crystal wafer. The entire grid structure is positioned such that the refracted light beam exits the crystal wafer on its rear face.
    Type: Grant
    Filed: March 5, 1999
    Date of Patent: March 20, 2001
    Assignee: Fraunhofer-Gesellschaft zur Forderung der angewandten Forschung e.V.
    Inventors: Vladimir Hinkov, Iliyana Hinkov
  • Patent number: 6201634
    Abstract: The present invention provides a method for calculating the birefringence of an optical element and selecting the direction of minimum birefringence in the optical element. A material for manufacturing the optical element is a fluoride single crystal with a birefringence value that is reduced compared to conventional materials. The fluoride single crystal is cut from a fluoride single crystal ingot obtained by crystal growth so that the {111} crystal planes are two parallel planes, after which the optical performance is improved by subjecting this material to a heat treatment. The birefringence of the optical element is calculated by converting known piezo-optical constants in a specified three-dimensional orthogonal coordinate system for the optical material into piezo-optical constants in an arbitrary three-dimensional orthogonal coordinate system.
    Type: Grant
    Filed: March 11, 1999
    Date of Patent: March 13, 2001
    Assignee: Nikon Corporation
    Inventors: Shigeru Sakuma, Shuuichi Takano
  • Patent number: 6172792
    Abstract: An apparatus for redirecting physical energy includes a substrate defining a first boundary of a region, a first electrode defining a second boundary of the region, the second boundary disposed opposite to the first boundary, a second electrode adjacent to the first boundary for cooperating with the first electrode to apply a non-uniform electric field to the region, the non-uniform electric field having electrical field intensities simultaneously including a first electric field intensity and a second electric field intensity, and a layer of material disposed in the region, the layer having a variable index of refraction responsive to the electric field intensities of the non-uniform electric field, the variable index of refraction including a first index of refraction in response to the first electric field intensity and a second index of refraction in response to the second electric field intensity.
    Type: Grant
    Filed: January 30, 1998
    Date of Patent: January 9, 2001
    Inventors: Mary Lou Jepsen, Phillip Alvelda
  • Patent number: 6167174
    Abstract: A multiport isolator provides optical isolation between pairs of optical fibers so that light may pass from a first fiber to a second fiber of the pair, but not from the second fiber to the first fiber. The multiport isolator has first and second coupling modules to couple light from different fibers, and an isolator module between the coupling modules to prevent light from passing from the second fiber to the first fiber of a fiber pair.
    Type: Grant
    Filed: October 27, 1998
    Date of Patent: December 26, 2000
    Assignee: ADC Telecommunications, Inc.
    Inventors: B. Barry Zhang, Liang-Ju Lu
  • Patent number: 6134031
    Abstract: The present invention is directed to an optical space switch accommodating a plurality of input light paths and output light paths. The optical space switch comprises a plurality of polarization control optical switches, each consisting essentially of: polarization control means having elements, one for each input light path, for rotating through 90.degree. the polarizing direction of light information incident from each input light path or otherwise retaining the polarizing direction thereof for output; and a light path routing element for routing the light path for the light information output from the polarization control means in accordance with the polarizing direction of the light information. These polarization control optical switches are arranged in a matrix pattern or coupled in cascade to implement a polarization control optical space switch.
    Type: Grant
    Filed: February 23, 1994
    Date of Patent: October 17, 2000
    Assignee: Fujitsu Limited
    Inventors: Tetsuya Nishi, Takuji Maeda, Satoshi Kuroyanagi, Tsuyoshi Yamamoto
  • Patent number: 6061167
    Abstract: An optical isolator capable of simultaneously transmitting a plurality of light beams emitted from a plurality of optical fibers in one direction. It includes a plurality of optical fibers for transmitting light beams; a pair of collimating lenses for converting the light beams, emitted from or entered into the optical fibers, into parallel light beams; a pair of symmetric birefringent elements having at least one tapered surface for emitting by polarization the plurality of parallel light beams having passed the collimating lenses, and condensing all the light beams traveling in a forward direction onto the optical fibers, respectively; and a Faraday rotator interposed between the birefringent elements for rotating the light beams incident thereto by 45 degrees. A plurality of tapered faces having the same tapered angle are formed on one surface of the birefringent element so that a plurality of light beams can be simultaneously transmitted in one direction.
    Type: Grant
    Filed: May 11, 1999
    Date of Patent: May 9, 2000
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jin Young Song