Patents by Inventor Alan A. Fennema

Alan A. Fennema 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).

  • Publication number: 20240073566
    Abstract: Advanced hologram techniques pre-calculate holograms to be displayed on an LCoS switch panel of a wavelength selective switch (WSS) module. The holograms are generated offline and are then stored on the WSS module for later retrieval. Each of the holograms is associated with a defined parameter, such as an attenuation level, and each of the holograms is configured to create a reconfigurable phase grating profile or pattern of the pixels of the LCoS switch panel. Each phase pattern selectively directs desired diffraction orders of optical channels from the LCoS switch panel for output to selected ports and selectively directs undesired diffraction orders away from the ports and at a desired attenuation level. During operation, the WSS module can retrieve the stored holograms. Interpolation can determine intermediate holograms between parameter values, and a ramp function can be added to the pattern to account for steering adjustments.
    Type: Application
    Filed: August 25, 2022
    Publication date: February 29, 2024
    Inventors: Alan A. FENNEMA, Haijun Yuan, Wilfredo C. NANITA, Oswald CORREYA, Jack R KELLY, Thomas J. Schwartz
  • Patent number: 10505656
    Abstract: An apparatus includes an optical wavelength selective switch that includes an optical wavelength separator, a layer of liquid crystal having a two-dimensional array of s electrically operable pixel regions, and an electronic controller connected to individual apply voltages across the pixel regions. The optical wavelength separator is configured to substantially direct individual wavelength ranges of light received at an input optical port to separate lateral areas of said layer of liquid crystal. The electronic controller is configured to apply the voltages such that at least one neighboring pair of the lateral areas have refractive indexes modulated along a first direction and are separated by a guard band of the pixel regions along a different second direction.
    Type: Grant
    Filed: March 29, 2018
    Date of Patent: December 10, 2019
    Assignee: Nokia Solutions and Networks Oy
    Inventor: Alan A Fennema
  • Publication number: 20180294912
    Abstract: An apparatus includes an optical wavelength selective switch that includes an optical wavelength separator, a layer of liquid crystal having a two-dimensional array of s electrically operable pixel regions, and an electronic controller connected to individual apply voltages across the pixel regions. The optical wavelength separator is configured to substantially direct individual wavelength ranges of light received at an input optical port to separate lateral areas of said layer of liquid crystal. The electronic controller is configured to apply the voltages such that at least one neighboring pair of the lateral areas have refractive indexes modulated along a first direction and are separated by a guard band of the pixel regions along a different second direction.
    Type: Application
    Filed: March 29, 2018
    Publication date: October 11, 2018
    Applicant: Nokia Solutions and Networks Oy
    Inventor: Alan A. Fennema
  • Patent number: 8032004
    Abstract: A format for accessing content such as a full-length move from an optical disc uses an XML description file stored on the disc to generate one or more screens that a user employs to access the content. The decoding requirements of a hardware or software player are reduced by discarding specific elements of an encoding standard such as MPEG4 that is used to encode the content on the disc. The maximum average and peak bitrates at which the data is transferred are limited to further reduce the demands on the player.
    Type: Grant
    Filed: August 14, 2007
    Date of Patent: October 4, 2011
    Assignee: Vmedia Research, Inc.
    Inventors: Dagan Packman, Steven Bernard Volk, Jerry E. Hurst, Jr., Alan Fennema
  • Patent number: 7518816
    Abstract: The present invention includes a method and apparatus to write and read copy protected data on a disc drive storage system by encoding and decoding data to be copy protected using servo wedge data as the encoding element. In one aspect, the drive is marked by a number generated from the servo wedge data.
    Type: Grant
    Filed: June 16, 2004
    Date of Patent: April 14, 2009
    Assignee: Seagate Technology LLC
    Inventors: Alan A. Fennema, Gayle L. Noble
  • Publication number: 20080273115
    Abstract: A format for accessing content such as a full-length move from an optical disc uses an XML description file stored on the disc to generate one or more screens that a user employs to access the content. The decoding requirements of a hardware or software player are reduced by discarding specific elements of an encoding standard such as MPEG4 that is used to encode the content on the disc. The maximum average and peak bitrates at which the data is transferred are limited to further reduce the demands on the player.
    Type: Application
    Filed: August 14, 2007
    Publication date: November 6, 2008
    Applicant: Vmedia Research, Inc.
    Inventors: Dagan Packman, Steven Bernard Volk, Jerry E. Hurst, Alan Fennema
  • Patent number: 6912235
    Abstract: An apparatus and method for controlling the phase of a tunable laser is provided. Stabilization of the mode of a laser beam is provided as the laser is tuned to a target frequency. For one embodiment, a laser generates a reference beam and an output beam. The power of each of beam is measured by optical detectors, and a ratio thereof is utilized to detect when a mode hop occurs as the laser is coarsely tuned. The average of the pre and post mode hop ratios is utilized as a control setpoint while finely tuning the laser to the target frequency. Wavelength lockers, optical power dividers and optical detectors are utilized to determine power levels of the reference and output beams while also monitoring frequency characteristics thereof. A control unit utilizes the outputs from the wavelength locker to control the operation of the extended cavity laser during and after tuning.
    Type: Grant
    Filed: July 31, 2002
    Date of Patent: June 28, 2005
    Assignee: Iolon, Inc.
    Inventors: Douglas W. Anthon, Jill D. Berger, Alexander A. Tselikov, Stephen J. Hrinya, Howard S. Lee, Alan A. Fennema, Man F. Cheung
  • Patent number: 6898221
    Abstract: An apparatus comprising a first reference element having an output power that varies monotonically with input frequency over an operating frequency range and receiving at least a portion of an output beam of light from an optical source. A second reference element having an output power that is frequency dependent receives at least a portion of the output beam of light. A first optical detector measures the power of a first reference beam of light from the first reference element. A second optical detector measures the power of a second reference beam of light from the second reference element. Electronic circuitry is coupled to the first and second optical detectors for receiving first and second reference signals therefrom and producing a coarse error signal for permitting coarse adjustment and a fine error signal for permitting fine adjustment of the frequency of the output beam of light.
    Type: Grant
    Filed: March 15, 2002
    Date of Patent: May 24, 2005
    Assignee: Iolon, Inc.
    Inventors: Jill D. Berger, Subrata K. Dutta, Alan A. Fennema, Olga A. Gorbounova, Stephen J. Hrinya, Fedor A. Ilkov, David A. King, Heather L. Tavernier, Alexander A. Tselikov
  • Patent number: 6898038
    Abstract: The present invention includes a method and apparatus to write and read copy protected data on a disc drive storage system by encoding and decoding data to be copy protected using servo wedge data as the encoding element. In one aspect, the drive is marked by a number generated from the servo wedge data.
    Type: Grant
    Filed: March 15, 2001
    Date of Patent: May 24, 2005
    Assignee: Seagate Technology, LLC
    Inventors: Alan A. Fennema, Gayle L. Noble
  • Publication number: 20040228237
    Abstract: The present invention includes a method and apparatus to write and read copy protected data on a disc drive storage system by encoding and decoding data to be copy protected using servo wedge data as the encoding element. In one aspect, the drive is marked by a number generated from the servo wedge data.
    Type: Application
    Filed: June 16, 2004
    Publication date: November 18, 2004
    Inventors: Alan A. Fennema, Gayle L. Noble
  • Publication number: 20040213306
    Abstract: An apparatus and method for controlling the phase of a tunable laser is provided. Stabilization of the mode of a laser beam is provided as the laser is tuned to a target frequency. For one embodiment, a laser generates a reference beam and an output beam. The power of each of beam is measured by optical detectors, and a ratio thereof is utilized to detect when a mode hop occurs as the laser is coarsely tuned. The average of the pre and post mode hop ratios is utilized as a control setpoint while finely tuning the laser to the target frequency. Wavelength lockers, optical power dividers and optical detectors are utilized to determine power levels of the reference and output beams while also monitoring frequency characteristics thereof. A control unit utilizes the outputs from the wavelength locker to control the operation of the extended cavity laser during and after tuning.
    Type: Application
    Filed: January 16, 2004
    Publication date: October 28, 2004
    Inventors: Alan A. Fennema, Howard S. Lee, Man F. Cheung
  • Patent number: 6785075
    Abstract: A disc drive with an information portion previously written on a rotatable disc surface, a servo write clock generator phase lock loop circuit controlling timing for writing a reference mark to the rotatable disc surface in substantial time alignment and phase and frequency coherent with the information portion previously written to the rotatable disc surface, a servo write clock generator phase lock loop circuit controlling timing for writing the reference mark, a pulse detector circuit for creating logic level signals from the reference mark, a pattern generator for generating reference mark write signals from the logic level signals, a memory buffer for storing radial position correction tables and values for writing the reference mark, and a self-servo control and sequencing circuit synchronizing timing signals for writing the reference mark to rotatable disc surface of disc drive.
    Type: Grant
    Filed: July 26, 2001
    Date of Patent: August 31, 2004
    Assignee: Seagate Technology LLC
    Inventors: Lawrence M. Bryant, Gabor Szïta, Alan A. Fennema, Karl A. Belser, Robert D. Murphy
  • Patent number: 6771443
    Abstract: A propagating method is provided in which timing and servo sector information is propagated throughout a data storage media that initially contains only a guide pattern. The method uses an offset between the write element and the read element in a read/write head to position and propagate the timing information. In addition, a method for circumferentially aligning timing and servo sector information is disclosed that utilizes a time delay to position the propagated timing and servo sector information. Another method for attenuating timing errors during timing and servo sector propagation to a data storage media is disclosed. Timing errors are attenuated through the use of phase locked loop circuit and measurement of the phase error detected between different tracks on the data storage media. Apparatuses implementing the methods including a storage device readable by a computer system that implements the methods are provided.
    Type: Grant
    Filed: July 26, 2001
    Date of Patent: August 3, 2004
    Assignee: Seagate Technology LLC
    Inventors: Gabor Szita, Lawrence Matthias Bryant, Karl Arnold Belser, Alan Fennema
  • Publication number: 20030026302
    Abstract: An apparatus and method for controlling the phase of a tunable laser is provided. Stabilization of the mode of a laser beam is provided as the laser is tuned to a target frequency. For one embodiment, a laser generates a reference beam and an output beam. The power of each of beam is measured by optical detectors, and a ratio thereof is utilized to detect when a mode hop occurs as the laser is coarsely tuned. The average of the pre and post mode hop ratios is utilized as a control setpoint while finely tuning the laser to the target frequency. Wavelength lockers, optical power dividers and optical detectors are utilized to determine power levels of the reference and output beams while also monitoring frequency characteristics thereof. A control unit utilizes the outputs from the wavelength locker to control the operation of the extended cavity laser during and after tuning.
    Type: Application
    Filed: July 31, 2002
    Publication date: February 6, 2003
    Inventors: Douglas W. Anthon, Jill D. Berger, Alexander A. Tselikov, Stephen J. Hrinya, Howard S. Lee, Alan A. Fennema, Man F. Cheung
  • Publication number: 20020164125
    Abstract: An apparatus comprising a first reference element having an output power that varies monotonically with input frequency over an operating frequency range and receiving at least a portion of an output beam of light from an optical source. A second reference element having an output power that is frequency dependent receives at least a portion of the output beam of light. A first optical detector measures the power of a first reference beam of light from the first reference element. A second optical detector measures the power of a second reference beam of light from the second reference element. Electronic circuitry is coupled to the first and second optical detectors for receiving first and second reference signals therefrom and producing a coarse error signal for permitting coarse adjustment and a fine error signal for permitting fine adjustment of the frequency of the output beam of light.
    Type: Application
    Filed: March 15, 2002
    Publication date: November 7, 2002
    Inventors: Jill D. Berger, Subrata K. Dutta, Alan A. Fennema, Olga A. Gorbounova, Stephen J. Hrinya, Fedor A. Ilkov, David A. King, Heather L. Tavernier, Alexander A. Tselikov
  • Publication number: 20020145817
    Abstract: A propagating method is provided in which timing and servo sector information is propagated throughout a data storage media that initially contains only a guide pattern. The method uses an offset between the write element and the read element in a read/write head to position and propagate the timing information. In addition, a method for circumferentially aligning timing and servo sector information is disclosed that utilizes a time delay to position the propagated timing and servo sector information. Another method for attenuating timing errors during timing and servo sector propagation to a data storage media is disclosed. Timing errors are attenuated through the use of phase locked loop circuit and measurement of the phase error detected between different tracks on the data storage media. Apparatuses implementing the methods including a storage device readable by a computer system that implements the methods are provided.
    Type: Application
    Filed: July 26, 2001
    Publication date: October 10, 2002
    Applicant: Seagate Technology LLC
    Inventors: Gabor Szita, Lawrence Matthias Bryant, Karl Arnold Belser, Alan Fennema
  • Publication number: 20020048107
    Abstract: A disc drive with an information portion previously written on a rotatable disc surface, a servo write clock generator phase lock loop circuit controlling timing for writing a reference mark to the rotatable disc surface in substantial time alignment and phase and frequency coherent with the information portion previously written to the rotatable disc surface, a servo write clock generator phase lock loop circuit controlling timing for writing the reference mark, a pulse detector circuit for creating logic level signals from the reference mark, a pattern generator for generating reference mark write signals from the logic level signals, a memory buffer for storing radial position correction tables and values for writing the reference mark, and a self-servo control and sequencing circuit synchronizing timing signals for writing the reference mark to rotatable disc surface of disc drive.
    Type: Application
    Filed: July 26, 2001
    Publication date: April 25, 2002
    Inventors: Lawrence M. Bryant, Gabor Szita, Alan A. Fennema, Karl A. Belser, Robert D. Murphy
  • Patent number: 6345021
    Abstract: A system and method for encoding servo sector information in a nonvolatile data storage and retrieval system using rotating recording disks. Servo sectors are angularly-spaced approximately radial regions reserved for position reference and tracking adjustment information. Servo timing marks including means for detecting defects on the recording surface, encoded track address and sector address data, and position error signal blocks are permanently fabricated into a number of servo sectors. The present invention helps the storage system controller locate, certify, and follow any particular track and sector while maximizing the amount of disk surface area available for data storage and retrieval.
    Type: Grant
    Filed: November 10, 1998
    Date of Patent: February 5, 2002
    Assignee: Seagate Technology
    Inventors: Karl A. Belser, Alan A. Fennema
  • Patent number: 5974019
    Abstract: A positioning system for selectively directing a first beam of light towards a destination and a second beam of light towards a first diffractive optic. The first beam of light and the second beam of light traverse a substantially co-linear optical path. The first diffractive optic diffracts the second beam of light into a plurality of optical spots. The second beam of light comprising the plurality of optical spots is directed onto a second diffractive optic. A change in position of the plurality of optical spots relative to the second diffractive optic is sensed in a reflection of the second beam of light by a detection element and representative signals are derived thereof. The signals are coupled to a directing assembly, which directs the first beam of light towards the destination.
    Type: Grant
    Filed: April 16, 1998
    Date of Patent: October 26, 1999
    Assignee: Seagate Technology, Inc.
    Inventors: Karl A. Belser, Joseph Drake, John H. Jerman, Alan A. Fennema
  • Patent number: 5499231
    Abstract: An optical disk drive with a multiple data layer optical disk uses computed axial velocity values of the data layers to optimize the interlayer transition of the focused light beam. In the preferred embodiment, the axial velocities of the data layers are computed for a set of radial and angular positions on the data layer surfaces using one of several techniques. The data layer axial velocity values are computed from the measured current values to the voice coil motor focus actuator or from the output of the detector that generates the focus error signal (FES). A routine is run at disk drive startup, or at various times during disk drive operation, to measure the coil current or FES at different radial and angular positions and compute the axial velocity values. The computed axial velocity values are then mapped into memory storage according to addresses corresponding to their radial and angular positions.
    Type: Grant
    Filed: November 15, 1994
    Date of Patent: March 12, 1996
    Assignee: International Business Machines Corporation
    Inventors: Alan A. Fennema, Wayne I. Imaino, Hal J. Rosen