Patents by Inventor Anthony S. Kewitsch

Anthony S. Kewitsch has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7848370
    Abstract: Semiconductor diode lasers are phase-locked by direct current injection and combined to form a single coherent output beam. The optical power is amplified by use of fiber amplifiers. Electronically control of the optical phases of each emitter enables power efficient combining of output beams to be maintained under dynamic conditions.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: December 7, 2010
    Assignee: Telaris Inc.
    Inventors: Anthony S. Kewitsch, George A. Rakuljic
  • Publication number: 20090296751
    Abstract: Semiconductor diode lasers are phase-locked by direct current injection and combined to form a single coherent output beam. The optical power is amplified by use of fiber amplifiers. Electronically control of the optical phases of each emitter enables power efficient combining of output beams to be maintained under dynamic conditions.
    Type: Application
    Filed: January 25, 2008
    Publication date: December 3, 2009
    Applicant: TELARIS INC.
    Inventors: ANTHONY S. KEWITSCH, GEORGE A. RAKULJIC
  • Publication number: 20080273844
    Abstract: Composite fiber optic cables having exposed, conductive traces external to the cable jacket enable non-invasive, wireless electrical tone tracing of fiber optic cables. The cross sectional geometry of the fiber optic cable prevents conductive traces from short circuiting when abutting other cables or grounded conductive elements. Moreover, the structure allows convenient electrical contact to the conductive traces at any location along the longitudinal extent of the cable without requiring penetration of the cable jacket or removal of fiber optic connectors. Traceable fiber optic cables of various types are disclosed, including simplex, duplex and ribbon cables. Systems of traceable cables utilizing connectors with integrated electrical antenna elements attached to the conductive elements of cable and RFID tags for remote connector port identification are further disclosed.
    Type: Application
    Filed: May 2, 2008
    Publication date: November 6, 2008
    Inventor: Anthony S. Kewitsch
  • Patent number: 7079320
    Abstract: Intrinsic material and optical properties of liquid crystal units, such as variable response to wavelength and temperature variations, are accommodated in accordance with the invention by introducing at least a pair of wave plates of different thicknesses which, together with the retardation introduced by the liquid crystal, serve to broaden the wavelength of response in fashion which also athermalizes the response. Specific retardations and angles of inclination relative to the input polarization are employed for overcoming these nonlinearlities.
    Type: Grant
    Filed: July 15, 2003
    Date of Patent: July 18, 2006
    Inventor: Anthony S. Kewitsch
  • Publication number: 20040244425
    Abstract: Systems devices and methods in accordance with the invention impart high strength index of refraction patterns to photosensitive optical devices, such as Bragg gratings written in optical fibers. A length of small diameter fiber retaining photosensitivity is fabricated by flame elongation of an optical fiber precursor having dopant containing cladding, using a diffuse, low velocity inverted flame that does not introduce water, OH or H2 into the fiber. By varying the flame velocity during each scan the fiber is diminished to a small, uniform diameter, waist region. Photosensitivity is preserved and enhanced by exposure of the prepared waist region to scanning actinic illumination within an in-diffusing environment of pressurizing hydrogen or deuterium, and controlling the exposure to optimize the photo-induced index change.
    Type: Application
    Filed: June 9, 2003
    Publication date: December 9, 2004
    Inventors: Xiaolin Tong, Anthony S. Kewitsch, George A. Rakuljic
  • Patent number: 6801310
    Abstract: For systems which disperse individual wavelength components of a DWDM beam into an array of converging beams, the individual wavelength signals are modified for blocking, equalization or other purposes by reflective liquid crystal cells. Thus modulated or modified components are then recombined by the system into an output beam, as by reverse passage through the system. Controlled full extinction or linear attenuation may be introduced by converging asymmetrical beams of separate polarization components for each wavelength into superposed relation on zero twist nematic crystal cells which are voltage controlled so as to retard for extinction of greater than 40 dB or to transform the state of polarization to a selected angle for attenuation. Polarization sensitive elements in the return paths of the reflected beams then filter the rejected components.
    Type: Grant
    Filed: August 2, 2002
    Date of Patent: October 5, 2004
    Assignee: Arroyo Optics, Inc.
    Inventors: Anthony S. Kewitsch, George Rakuljic, Victor Leyva
  • Patent number: 6795182
    Abstract: Systems and methods for modifying, switching, rearranging or otherwise controlling the individual wavelength components of DWDM optical signals are described, which employ compact refolding and reshaping of these dimensionally patterned beams within a confined volume. The wavelength components of the beam are diffractively dispersed with high diffraction efficiency, and then reversely converged to beam waists incident on different ones of an array of control elements such as liquid crystal cells, MEMs and other spatial light modulators, or fixed distributed patterns. With reflective control elements the wavelength components may be reversely refolded along reciprocal paths with rediffraction, to form a reconstituted and revised DWDM output signal. If the control elements transmit at least one of the wavelength components, a separate, adjacent three dimensional beam refolding path, with rediffraction, is used to feed recombined signals to a separate output.
    Type: Grant
    Filed: July 3, 2002
    Date of Patent: September 21, 2004
    Assignee: Arroyo Optics, Inc.
    Inventors: George Rakuljic, Anthony S. Kewitsch, Victor Leyva
  • Patent number: 6603903
    Abstract: Systems devices and methods in accordance with the invention impart high strength index of refraction patterns to photosensitive optical devices, such as Bragg gratings written in optical fibers. A length of small diameter fiber retaining photosensitivity is fabricated by flame elongation of an optical fiber precursor having dopant containing cladding, using a diffuse, low velocity inverted flame that does not introduce water, OH or H2 into the fiber. By varying the flame velocity during each scan the fiber is diminished to a small, uniform diameter, waist region. Photosensitivity is preserved and enhanced by exposure of the prepared waist region to scanning actinic illumination within an in-diffusing environment of pressurizing hydrogen or deuterium, and controlling the exposure to optimize the photo-induced index change.
    Type: Grant
    Filed: March 6, 2001
    Date of Patent: August 5, 2003
    Assignee: Arroyo Optics Inc.
    Inventors: Xiaolin Tong, Anthony S. Kewitsch, George A. Rakuljic
  • Patent number: 6578388
    Abstract: An add/drop filter for optical wave energy incorporates a Bragg grating in a very narrow waist region defined by merged lengths of elongated optical fibers. Light is propagated into the waist region via adiabatically tapered fibers and is transformed from two longitudinally adjacent fibers into two orthogonal modes within the air-glass waveguide of the waist and reflected off the grating from one fiber into the other. The geometry of the waist region is such that the reflected drop wavelength is polarization independent, without lossy peaks in the wavelength band of interest. Additionally, back reflection are shifted out of the wavelength band of interest. High strength gratings are written by photosensitizing the waist region fibers by constantly in-diffusing pressurized hydrogen or deuterium. For narrow spectral bandwidth gratings, dimensional variations must be minimized or compensated, and the grating is apodized by both a.c. and d.c. variations in writing beams at a net constant power.
    Type: Grant
    Filed: November 27, 2000
    Date of Patent: June 17, 2003
    Assignee: Arroyo Optics Inc.
    Inventors: Anthony S. Kewitsch, George A. Rakuljic, Phil A. Willems, Xiaolin Tong
  • Publication number: 20030095305
    Abstract: For systems which disperse individual wavelength components of a DWDM beam into an array of converging beams, the individual wavelength signals are modified for blocking, equalization or other purposes by reflective liquid crystal cells. Thus modulated or modified components are then recombined by the system into an output beam, as by reverse passage through the system. Controlled full extinction or linear attenuation may be introduced by converging asymmetrical beams of separate polarization components for each wavelength into superposed relation on zero twist nematic crystal cells which are voltage controlled so as to retard for extinction of greater than 40 dB or to transform the state of polarization to a selected angle for attenuation. Polarization sensitive elements in the return paths of the reflected beams then filter the rejected components.
    Type: Application
    Filed: August 2, 2002
    Publication date: May 22, 2003
    Applicant: Arroyo Optics, Inc.
    Inventors: Anthony S. Kewitsch, George Rakuljic, Victor Leyva
  • Patent number: 6546170
    Abstract: Asymmetric grating assisted couplers present unique problems if dispersion is to be reduced to levels at which high data rate signals can be transmitted. To overcome these problems, the method of the present invention includes precisely controlling and monitoring the cross-sectional geometry of the coupler during stretching and fusing. By monitoring states of polarization in lowest order modes as the coupler is formed, coupler fusion can be terminated when optimum form birefringence minimizing PMD is achieved. Dispersion is further minimized by impressing a saturated index of refraction grating with substantially flat add/drop characteristics in the coupler, and introducing a controlled amount of twist.
    Type: Grant
    Filed: March 6, 2001
    Date of Patent: April 8, 2003
    Assignee: Arroyo Optics, Inc.
    Inventors: Avishay Eyal, Anthony S. Kewitsch, George A. Rakuljic
  • Publication number: 20030011769
    Abstract: Systems and methods for modifying, switching, rearranging or otherwise controlling the individual wavelength components of DWDM optical signals are described, which employ compact refolding and reshaping of these dimensionally patterned beams within a confined volume. The wavelength components of the beam are diffractively dispersed with high diffraction efficiency, and then reversely converged to beam waists incident on different ones of an array of control elements such as liquid crystal cells, MEMs and other spatial light modulators, or fixed distributed patterns. With reflective control elements the wavelength components may be reversely refolded along reciprocal paths with rediffraction, to form a reconstituted and revised DWDM output signal. If the control elements transmit at least one of the wavelength components, a separate, adjacent three dimensional beam refolding path, with rediffraction, is used to feed recombined signals to a separate output.
    Type: Application
    Filed: July 3, 2002
    Publication date: January 16, 2003
    Applicant: Arroyo Optics, Inc.
    Inventors: George Rakuljic, Anthony S. Kewitsch, Victor Leyva
  • Patent number: 6465153
    Abstract: Advantageous methodologies are disclosed for embedding periodic patterns in optical waveguide elements such as optical fibers. Polarization independence in an elongated waist region of a coupler can be established by measuring polarization characteristics during fusion and elongation, and controlling the heating and stretching to impart a cross-sectional shape, such as a hybrid dumbbell-ellipsoid produces a polarization insensitive drop wavelength. Alternatively, or additionally, polarization dependence can be minimized by angular deformation of the elements along its light transmissive axis. In addition, an element of relatively low photosensitivity is held in an hydrogen or deuterium environment pressurized to about 1000 to 5000 psi. While the environment is pressurized, a scanning UV beam is transmitted through a photomask and impinges on the coupler waist. In writing the grating, the in-diffused gas is constantly replenished, enabling the grating to grow.
    Type: Grant
    Filed: October 31, 2000
    Date of Patent: October 15, 2002
    Assignee: Arroyo Optics, Inc.
    Inventors: Anthony S. Kewitsch, George A. Rakuljic, Doruk Engin, Seth J. Greenberg, Phil A. Willems, Xiaolin Tong
  • Patent number: 6459487
    Abstract: Optical components, particularly microoptic glass components used in synthesizing birefringence in filter systems based on polarization interferometer techniques, are fabricated using systems and methods which provide accurate frequency periodicity measurements. These measurements are derived from differential delays induced by in-process glass elements between beam components in a polarization interferometer unit and from progressive wavelength scanning across a wavelength band of interest. The consequent sinusoidal output variation has peak to peak spacings which are measured to provide frequency periodicity values from which precise length corrections for the optical elements can be calculated.
    Type: Grant
    Filed: September 4, 2001
    Date of Patent: October 1, 2002
    Inventors: Gang Paul Chen, Avishay Eyal, Anthony S. Kewitsch, Victor Leyva, George A. Rakuljic
  • Patent number: 6445851
    Abstract: Optical filter devices in accordance with the invention are based on tapered optical fibers having transversely distributed refractive index variations in a small diameter waist region where waves are propagated in combined cladding/air-guided modes. The grating has a periodicity selected for reflection of a selected center wavelength and the waist diameter and grating pattern split the wavelengths of the lossy cladding modes from the backreflected signals by more than 10 nm. Such wavelength selective optical fiber devices have a variety of applications. In one application, a tapered fiber grating with optical circulators is used to add or drop optical signals for communication via a common transmission path. In another application, the tapered fiber grating is used with grating assisted mode couplers and circulators to form an add/drop multiplexer. In another application, these components are used with optical switches to produce programmable add/drop filters and crossconnects.
    Type: Grant
    Filed: December 15, 1999
    Date of Patent: September 3, 2002
    Assignee: Arroyo Optics Inc.
    Inventors: George A. Rakuljic, Anthony S. Kewitsch
  • Publication number: 20020093662
    Abstract: Optical components, particularly microoptic glass components used in synthesizing birefringence in filter systems based on polarization interferometer techniques, are fabricated using systems and methods which provide accurate frequency periodicity measurements. These measurements are derived from differential delays induced by in-process glass elements between beam components in a polarization interferometer unit and from progressive wavelength scanning across a wavelength band of interest. The consequent sinusoidal output variation has peak to peak spacings which are measured to provide frequency periodicity values from which precise length corrections for the optical elements can be calculated.
    Type: Application
    Filed: September 4, 2001
    Publication date: July 18, 2002
    Inventors: Gang Paul Chen, Avishay Eyal, Anthony S. Kewitsch, Victor Leyva, George A. Rakuljic
  • Publication number: 20020085252
    Abstract: Interleavers for optical systems, including multiplexers and demultiplexers, are based on the use of non-birefringent elements in combination with polarization beam splitter to provide differential retardation effects for generation of precise transmittance functions. The retardation elements, in one particular example, are non-birefringent glasses arranged in individually athermal stages but the optical beams propagated through them are maintained in selected polarization states in each stage. Between or within the stages the polarization vectors are varied to match phase to a selected standard, such as an ITU grid. Within the stages, selected beam angle adjustments are made to shape the output transmittance characteristic.
    Type: Application
    Filed: July 5, 2001
    Publication date: July 4, 2002
    Inventors: Gang Paul Chen, Avishay Eyal, Anthony S. Kewitsch, Victor Leyva, William K. Marshall, George A. Rakuljic, Xiaolin Tong, Xian Li Yeh, Don Zambos
  • Patent number: 6387593
    Abstract: A polymer material is exposed to radiation of a type that changes some aspect of the polymer's radiation passing properties. The radiation that caused the property change is then contained by the material. The property change can be self-focusing or self-trapping light can be used. In that case, the same light that causes the photopolymerization is contained by the change in index of refraction that is caused by the polymerization.
    Type: Grant
    Filed: November 18, 1999
    Date of Patent: May 14, 2002
    Assignee: California Institute of Technology
    Inventors: Anthony S. Kewitsch, Amnon Yariv
  • Publication number: 20020045103
    Abstract: Polymer techniques are used to reduce the feature size in electrical or mechanical processes. A first embodiment uses a light sensitive polymer. A first illumination forms a lens structure. A second illumination is focused by that lens structure to form a final feature. The lens can then be removed. A second embodiment uses holographic techniques to pattern polymers and form consistent pores within the polymers.
    Type: Application
    Filed: August 28, 2001
    Publication date: April 18, 2002
    Applicant: California Institute of Technology
    Inventors: Anthony S. Kewitsch, Amnon Yariv
  • Patent number: 6289699
    Abstract: A wavelength selective optical fiber coupler having various applications in the field of optical communications is disclosed. The coupler is composed of dissimilar waveguides in close proximity. A light induced, permanent index of refraction grating is recorded in the coupler waist The grating filters and transfers energy within a particular range of wavelengths from a first waveguide to a second waveguide. Transversely asymmetric gratings provide an efficient means of energy transfer. The coupler can be used to combine or multiplex a plurality of lasers operating at slightly different wavelengths into a single fiber. Other embodiments such as a dispersion compensator and gain flattening filter are disclosed.
    Type: Grant
    Filed: March 6, 1998
    Date of Patent: September 18, 2001
    Assignee: Arroyo Optics, Inc.
    Inventors: Anthony S. Kewitsch, George A. Rakuljic, Amnon Yariv