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).
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Publication number: 20240073566Abstract: 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: ApplicationFiled: August 25, 2022Publication date: February 29, 2024Inventors: Alan A. FENNEMA, Haijun Yuan, Wilfredo C. NANITA, Oswald CORREYA, Jack R KELLY, Thomas J. Schwartz
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Patent number: 10505656Abstract: 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: GrantFiled: March 29, 2018Date of Patent: December 10, 2019Assignee: Nokia Solutions and Networks OyInventor: Alan A Fennema
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Publication number: 20180294912Abstract: 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: ApplicationFiled: March 29, 2018Publication date: October 11, 2018Applicant: Nokia Solutions and Networks OyInventor: Alan A. Fennema
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Patent number: 8032004Abstract: 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: GrantFiled: August 14, 2007Date of Patent: October 4, 2011Assignee: Vmedia Research, Inc.Inventors: Dagan Packman, Steven Bernard Volk, Jerry E. Hurst, Jr., Alan Fennema
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Patent number: 7518816Abstract: 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: GrantFiled: June 16, 2004Date of Patent: April 14, 2009Assignee: Seagate Technology LLCInventors: Alan A. Fennema, Gayle L. Noble
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Publication number: 20080273115Abstract: 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: ApplicationFiled: August 14, 2007Publication date: November 6, 2008Applicant: Vmedia Research, Inc.Inventors: Dagan Packman, Steven Bernard Volk, Jerry E. Hurst, Alan Fennema
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Patent number: 6912235Abstract: 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: GrantFiled: July 31, 2002Date of Patent: June 28, 2005Assignee: Iolon, Inc.Inventors: Douglas W. Anthon, Jill D. Berger, Alexander A. Tselikov, Stephen J. Hrinya, Howard S. Lee, Alan A. Fennema, Man F. Cheung
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Patent number: 6898221Abstract: 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: GrantFiled: March 15, 2002Date of Patent: May 24, 2005Assignee: 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
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Patent number: 6898038Abstract: 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: GrantFiled: March 15, 2001Date of Patent: May 24, 2005Assignee: Seagate Technology, LLCInventors: Alan A. Fennema, Gayle L. Noble
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Publication number: 20040228237Abstract: 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: ApplicationFiled: June 16, 2004Publication date: November 18, 2004Inventors: Alan A. Fennema, Gayle L. Noble
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Publication number: 20040213306Abstract: 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: ApplicationFiled: January 16, 2004Publication date: October 28, 2004Inventors: Alan A. Fennema, Howard S. Lee, Man F. Cheung
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Patent number: 6785075Abstract: 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: GrantFiled: July 26, 2001Date of Patent: August 31, 2004Assignee: Seagate Technology LLCInventors: Lawrence M. Bryant, Gabor Szïta, Alan A. Fennema, Karl A. Belser, Robert D. Murphy
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Patent number: 6771443Abstract: 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: GrantFiled: July 26, 2001Date of Patent: August 3, 2004Assignee: Seagate Technology LLCInventors: Gabor Szita, Lawrence Matthias Bryant, Karl Arnold Belser, Alan Fennema
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Publication number: 20030026302Abstract: 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: ApplicationFiled: July 31, 2002Publication date: February 6, 2003Inventors: Douglas W. Anthon, Jill D. Berger, Alexander A. Tselikov, Stephen J. Hrinya, Howard S. Lee, Alan A. Fennema, Man F. Cheung
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Publication number: 20020164125Abstract: 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: ApplicationFiled: March 15, 2002Publication date: November 7, 2002Inventors: 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
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Publication number: 20020145817Abstract: 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: ApplicationFiled: July 26, 2001Publication date: October 10, 2002Applicant: Seagate Technology LLCInventors: Gabor Szita, Lawrence Matthias Bryant, Karl Arnold Belser, Alan Fennema
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Publication number: 20020048107Abstract: 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: ApplicationFiled: July 26, 2001Publication date: April 25, 2002Inventors: Lawrence M. Bryant, Gabor Szita, Alan A. Fennema, Karl A. Belser, Robert D. Murphy
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Patent number: 6345021Abstract: 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: GrantFiled: November 10, 1998Date of Patent: February 5, 2002Assignee: Seagate TechnologyInventors: Karl A. Belser, Alan A. Fennema
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Patent number: 5974019Abstract: 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: GrantFiled: April 16, 1998Date of Patent: October 26, 1999Assignee: Seagate Technology, Inc.Inventors: Karl A. Belser, Joseph Drake, John H. Jerman, Alan A. Fennema
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Patent number: 5499231Abstract: 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: GrantFiled: November 15, 1994Date of Patent: March 12, 1996Assignee: International Business Machines CorporationInventors: Alan A. Fennema, Wayne I. Imaino, Hal J. Rosen