Patents by Inventor James L. Lafuse
James L. Lafuse 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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Patent number: 7756424Abstract: An optical code division multiple access communication system using a processor processes at least one collimated input beam which has been modulated with a data signal to produce multiple time-delayed output beams. The multiple time-delayed output beams are spatially distributed and independently phase shifted. An integration lens receives the phase modulated output beams and reintegrates the phase modulated output beams into a single encoded beam with a time series chip sequence. The integrated encoded beam is transmitted. A receiving system includes a processor to process the encoded collimated light beams received from a transmitter to produce multiple time-delayed output beams. The multiple time-delayed output beams are spatially distributed and independently phase shifted. An integration lens receives the phase-shifted output beams and reintegrates the phase-shifted output beams into a single decoded beam.Type: GrantFiled: January 22, 2002Date of Patent: July 13, 2010Assignee: Northrop Grumman Systems CorporationInventors: Terry M. Turpin, James L. Lafuse
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Patent number: 7509048Abstract: An Optical Tapped Delay Line (OTDL), which resolves multiple wavelength signals having extremely narrow wavelength spacing, is combined with other known optical devices to provide a wide variety of optical signal processing applications, including: multiplexing and de-multiplexing a multi-channel signal; adding a signal to, or dropping a signal from, a multi-channel optical signal; specialized coding processing such as generating code division multiple access signals; wavelength locking (stabilizing) a signal; filtering a signal; and analyzing and monitoring a signal spectrum. The OTDL spatially separates individual channels to allow separate processing on each channel. Fixed and tunable embodiments are identified in appropriate cases. Bulk, hybrid, and integrated optical embodiment and methods of fabrication are described, as are curved self-focusing and evanescent embodiments of OTDL devices.Type: GrantFiled: July 22, 2002Date of Patent: March 24, 2009Assignee: Essex CorporationInventors: Terry M. Turpin, Craig H. Price, Fred F. Froelich, Bruce D. Nichols, James L. Lafuse, Keith R. Frampton
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Patent number: 7215277Abstract: Methods for mitigating sidelobes and aliases, providing levels of suppression in excess of 20 dB. The methods may include 1) a version of the CLEAN algorithm developed in radio astronomy, modified to work on sub-aperture images; 2) weighting functions based on the phase and amplitude statistics of the sub-aperture image pixels to select points in the CLEAN algorithm; and 3) weighting functions based on the phase and amplitude statistics of the sub-aperture image pixels to mitigate sidelobes and aliases, in conjunction with CLEAN or separately. The methods may be used with all synthetic aperture techniques and are not limited to SAR.Type: GrantFiled: December 6, 2005Date of Patent: May 8, 2007Assignee: Essex Corp.Inventors: Paul W. Woodford, Gerald Davieau, James L. Lafuse
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Patent number: 7130292Abstract: A method and apparatus for enhancing the receiving and information identification functions of multiple access communications systems by employing one or more optical processors configured as a bank of 1-D correlators. The present invention is particularly useful in a DS/SS CDMA communications system, resulting in a multiuser CDMA system that approaches carrier to noise performance (C/N) as opposed to being limited by multiple access interference (MAI). The correlators are arranged in parallel to detect and/or demodulate the received signal, in conjunction with one or more complex algorithms to perform near-optimum multiuser detection, perform multipath combining and/or perform carrier Doppler compensation.Type: GrantFiled: January 19, 2001Date of Patent: October 31, 2006Assignee: Essex CorporationInventors: Terry M. Turpin, James L. Lafuse
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Patent number: 7042386Abstract: Methods for mitigating sidelobes and aliases, providing levels of suppression in excess of 20 dB. The methods may include 1) a version of the CLEAN algorithm developed in radio astronomy, modified to work on sub-aperture images; 2) weighting functions based on the phase and amplitude statistics of the sub-aperture image pixels to select points in the CLEAN algorithm; and 3) weighting functions based on the phase and amplitude statistics of the sub-aperture image pixels to mitigate sidelobes and aliases, in conjunction with CLEAN or separately. The methods may be used with all synthetic aperture techniques and are not limited to SAR.Type: GrantFiled: April 28, 2004Date of Patent: May 9, 2006Assignee: Essex CorporationInventors: Paul W. Woodford, Gerald Davieau, James L. Lafuse
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Publication number: 20040227659Abstract: Methods for mitigating sidelobes and aliases, providing levels of suppression in excess of 20 dB. The methods may include 1) a version of the CLEAN algorithm developed in radio astronomy, modified to work on sub-aperture images; 2) weighting functions based on the phase and amplitude statistics of the sub-aperture image pixels to select points in the CLEAN algorithm; and 3) weighting functions based on the phase and amplitude statistics of the sub-aperture image pixels to mitigate sidelobes and aliases, in conjunction with CLEAN or separately. The methods may be used with all synthetic aperture techniques and are not limited to SAR.Type: ApplicationFiled: April 28, 2004Publication date: November 18, 2004Applicant: Essex Corp.Inventors: Paul W. Woodford, Gerald Davieau, James L. Lafuse
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Publication number: 20030128917Abstract: An Optical Tapped Delay Line (OTDL), which resolves multiple wavelength signals having extremely narrow wavelength spacing, is combined with other known optical devices to provide a wide variety of optical signal processing applications, including: multiplexing and de-multiplexing a multi-channel signal; adding a signal to, or dropping a signal from, a multi-channel optical signal; specialized coding processing such as generating code division multiple access signals; wavelength locking (stabilizing) a signal; filtering a signal; and analyzing and monitoring a signal spectrum. The OTDL spatially separates individual channels to allow separate processing on each channel. Fixed and tunable embodiments are identified in appropriate cases. Bulk, hybrid, and integrated optical embodiment and methods of fabrication are described, as are curved self-focusing and evanescent embodiments of OTDL devices.Type: ApplicationFiled: July 22, 2002Publication date: July 10, 2003Inventors: Terry M. Turpin, Craig H. Price, Fred F. Froelich, Bruce D. Nichols, James L. Lafuse, Keith Frampton
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Publication number: 20020126644Abstract: A method and apparatus for enhancing the receiving and information identification functions of multiple access communications systems by employing one or more optical processors configured as a bank of 1-D correlators. The present invention is particularly useful in a DS/SS CDMA communications system, resulting in a multiuser CDMA system that approaches carrier to noise performance (C/N) as opposed to being limited by multiple access interference (MAI). The correlators are arranged in parallel to detect and/or demodulate the received signal, in conjunction with one or more complex algorithms to perform near-optimum multiuser detection, perform multipath combining and/or perform carrier Doppler compensation.Type: ApplicationFiled: January 19, 2001Publication date: September 12, 2002Inventors: Terry M. Turpin, James L. Lafuse
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Publication number: 20020105705Abstract: An optical code division multiple access communication system using a processor processes at least one collimated input beam which has been modulated with a data signal to produce multiple time-delayed output beams. The multiple time-delayed output beams are spatially distributed and independently phase shifted. An integration lens receives the phase modulated output beams and reintegrates the phase modulated output beams into a single encoded beam with a time series chip sequence. The integrated encoded beam is transmitted. A receiving system includes a processor to process the encoded collimated light beams received from a transmitter to produce multiple time-delayed output beams. The multiple time-delayed output beams are spatially distributed and independently phase shifted. An integration lens receives the phase-shifted output beams and reintegrates the phase-shifted output beams into a single decoded beam.Type: ApplicationFiled: January 22, 2002Publication date: August 8, 2002Inventors: Terry M. Turpin, James L. Lafuse
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Patent number: 5202776Abstract: Optical systems are disclosed which are capable of generating and rapidly changing time delays of electrical signals for true time delay beam formation and beam steering. The systems utilize an interferometer configuration. A first optical modulator and a Fourier transform lens define a Fourier transform plane in a first leg of the interferometer. In a second leg of the interferometer, a second optical modulator provides beam steering to a prism stack, which produces a set of plane reference waves having a range of orientations required to generate a desired range of time delays. Preferably the optical modulators are acousto optic Bragg cells. Alternatively, a holographic optic element could be used in place of the prism stack.Type: GrantFiled: December 12, 1991Date of Patent: April 13, 1993Assignee: Essex CorporationInventors: Leslie H. Gesell, James L. Lafuse