Patents by Inventor Roger J. Helkey
Roger J. Helkey 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: 7142744Abstract: A method for equalizing optical signal power in a group of optical signals transmitted through an optical switch in an optical transmission system. In one embodiment a group of optical signals is input into an optical switch having at least one movable mirror array with a plurality of reflectors formed thereon, the optical beam being directed onto a selected at least one reflector and wherein attenuating the optical beam is accomplished by controllably detuning at least one of the selected at least one reflector to attenuate the optical beam.Type: GrantFiled: February 24, 2005Date of Patent: November 28, 2006Assignee: Calient NetworksInventors: Tony Walter, Dan Blumenthal, John E. Bowers, Peter Hunt, Roger J. Helkey, Xuezhe Zheng
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Patent number: 6950215Abstract: An optical switching apparatus is provided. Generally, a plurality of optical input switches is provided. A plurality of optical output switches is provided. A plurality of central optical switches connected between the plurality of input switches and plurality of output switches is provided. A plurality of test light sources, where each test light source is connected to an optical input switch, is provided. A first plurality of optical detectors connected to the optical output switches is provided.Type: GrantFiled: July 11, 2001Date of Patent: September 27, 2005Assignee: Calient NetworksInventors: Walt Fant, Roger J. Helkey, Tony Walter, Peter Hunt, David Welsh
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Patent number: 6819815Abstract: An optical switch embodiment includes a switching array of arranged to accomplish switching of input light beams to any of a plurality of output channels and an array of beam monitoring elements for indirectly measuring and providing information used for adjusting output beams. The beam monitoring element further includes means for measuring the angular misalignment and the positional misalignment of a monitor beam and adjusting the reflectors based on monitor beam information such that optical beams are output from the switch having the desired optical characteristics, such as optimized power. Another optical switch embodiment includes an array of rhomboid prism assemblies positioned to receive the output beams from the switching array and such that the beams are split into substantially parallel working and monitor beams.Type: GrantFiled: December 12, 2001Date of Patent: November 16, 2004Assignee: Calient NetworksInventors: Charles Corbalis, John E. Bowers, Shifu Yuan, David Welsh, Roger J. Helkey
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Publication number: 20040120636Abstract: A method for equalizing optical signal power in a group of optical signals transmitted through an optical switch in an optical transmission system. In one embodiment a group of optical signals is input into an optical switch having at least one movable mirror array with a plurality of reflectors formed thereon, the optical beam being directed onto a selected at least one reflector and wherein attenuating the optical beam is accomplished by controllably detuning at least one of the selected at least one reflector to attenuate the optical beam.Type: ApplicationFiled: December 10, 2003Publication date: June 24, 2004Applicant: Calient NetworksInventors: Tony Walter, Dan Blumenthal, John E. Bowers, Peter Hunt, Roger J. Helkey, Xuezhe Zheng
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Patent number: 6697547Abstract: A method for equalizing optical signal power in a group of optical signals transmitted through an optical switch in an optical transmission system. In one embodiment a group of optical signals is input into an optical switch having at least one movable mirror array with a plurality of reflectors formed thereon, the optical beam being directed onto a selected at least one reflector and wherein attenuating the optical beam is accomplished by controllably detuning at least one of the selected at least one reflector to attenuate the optical beam.Type: GrantFiled: May 14, 2001Date of Patent: February 24, 2004Assignee: Calient NetworksInventors: Tony Walter, Dan Blumenthal, John E. Bowers, Peter Hunt, Roger J. Helkey, Xuezhe Zheng
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Publication number: 20030012481Abstract: An optical switching apparatus is provided. Generally, a plurality of optical input switches is provided. A plurality of optical output switches is provided. A plurality of central optical switches connected between the plurality of input switches and plurality of output switches is provided. A plurality of test light sources, where each test light source is connected to an optical input switch, is provided. A first plurality of optical detectors connected to the optical output switches is provided.Type: ApplicationFiled: July 11, 2001Publication date: January 16, 2003Inventors: Walt Fant, Roger J. Helkey, Tony Walter, Peter Hunt, David Welsh
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Publication number: 20020168131Abstract: A method for equalizing optical signal power in a group of optical signals transmitted through an optical switch in an optical transmission system. In one embodiment a group of optical signals is input into an optical switch having at least one movable mirror array with a plurality of reflectors formed thereon, the optical beam being directed onto a selected at least one reflector and wherein attenuating the optical beam is accomplished by controllably detuning at least one of the selected at least one reflector to attenuate the optical beam.Type: ApplicationFiled: May 14, 2001Publication date: November 14, 2002Inventors: Tony Walter, Dan Blumenthal, John E. Bowers, Peter Hunt, Roger J. Helkey, Xuezhe Zheng
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Patent number: 6028424Abstract: A linearized optical sampler is described. The optical sampler includes an electro-optic modulator having an optical signal input, an electrical signal input, and at least two optical signal outputs that generate at least two modulated optical signals. The optical sampler also includes at least two detectors each of which being optically coupled to a respective one of the at least two modulated optical signals. Each detector generates an electrical signal in response to an optical intensity of the respective one of the at least two modulated optical signals. The optical sampler also includes a signal processor electrically connected to each of the at least two detectors. The signal processor applies an inverse transform of the modulator transfer function. The signal processor also generates an electrical signal from the electrical signals generated by the detectors and from the inverse transform that is linearly related to an RF signal electrically that is coupled to the electrical signal input.Type: GrantFiled: April 6, 1999Date of Patent: February 22, 2000Assignee: Massachuetts Institute of TechnologyInventors: Jonathan C. Twichell, Roger J. Helkey
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Patent number: 5955875Abstract: A linearized optical sampler is described. The optical sampler includes an electro-optic modulator having an optical signal input, an electrical signal input, and at least two optical signal outputs that generate at least two modulated optical signals. The optical sampler also includes at least two detectors each of which being optically coupled to a respective one of the at least two modulated optical signals. Each detector generates an electrical signal in response to an optical intensity of the respective one of the at least two modulated optical signals. The optical sampler also includes a signal processor electrically connected to each of the at least two detectors. The signal processor applies an inverse transform of the modulator transfer function. The signal processor also generates an electrical signal from the electrical signals generated by the detectors and from the inverse transform that is linearly related to an RF signal electrically that is coupled to the electrical signal input.Type: GrantFiled: January 31, 1997Date of Patent: September 21, 1999Assignee: Massachusetts Institute of TechnologyInventors: Jonathan C. Twichell, Roger J. Helkey
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Patent number: 5802084Abstract: The mode-locked laser with improved pulse power output can be realized by combining an optical oscillator with a flared CW or modulated gain amplifier. An optical filter or isolator may be disposed between the oscillator and amplifier to avoid feedback of spontaneous noise. A two-segment laser is devised by providing a flared gain section between a modulated gain section and an absorber section within the integrated semiconductor laser. The flared section may taper from a larger modulated gain section to a smaller cross section absorber section or vice versa. Various combinations of absorber sections coupled to modulated gain sections by CW gain or passive flared gain sections may be combined with various arrangements of reflectors and tapered CW gain amplifiers are cascades of such amplifiers and modulated gain pairs.Type: GrantFiled: November 14, 1994Date of Patent: September 1, 1998Assignee: The Regents of the University of CaliforniaInventors: John E. Bowers, Alan Mar, Roger J. Helkey, Judy Karin
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Patent number: 5799024Abstract: The mode-locked laser with improved pulse power output can be realized by combining an optical oscillator with a flared CW or modulated gain amplifier. An optical filter or isolator may be disposed between the oscillator and amplifier to avoid feedback of spontaneous noise. A two-segment laser is devised by providing a flared gain section between a modulated gain section and an absorber section within the integrated semiconductor laser. The flared section may taper from a larger modulated gain section to a smaller cross section absorber section or vice versa. Various combinations of absorber sections coupled to modulated gain sections by CW gain or passive flared gain sections may be combined with various arrangements of reflectors and tapered CW gain amplifiers are cascades of such amplifiers and modulated gain pairs.Type: GrantFiled: December 19, 1996Date of Patent: August 25, 1998Assignee: The Regents of the University of CaliforniaInventors: John E. Bowers, Alan Mar, Roger J. Helkey, Judy Karin
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Patent number: 5293170Abstract: A Global Positioning System (GPS) commercial receiver is provided with a digital processor that can utilize to advantage P-code modulated L1 and L2 satellite signals which have been modulated with an unknown security code. Integration of the L1 and L2 signals, after demodulation by locally generated carrier and P-code signals, is repetitively accomplished over a duration that is estimated to be the period of the modulation code. The C/A-code L1 signal, which is not modulated with the unknown security code, is also used in locking the locally generated carrier and P-code generators in phase with the received L1 and L2 satellite signals. A interpolative technique is used for adjusting the phase of the locally generated carriers and code in increments much smaller than the period clock sources. Those locked phases can then be utilized to determine position, distance, time, etc., as is done in GPS receivers not utilizing the anti-spoofed signals but with increased accuracy and resolution.Type: GrantFiled: April 6, 1992Date of Patent: March 8, 1994Assignee: Ashtech Inc.Inventors: Robert G. Lorenz, Roger J. Helkey, Kamran K. Abadi
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Patent number: 5134407Abstract: A Global Positioning System (GPS) commercial receiver is provided with a digital processor that can utilize to advantage P-code modulated L1 and L2 satellite signals which have been modulated with an unknown security code. Integration of the L1 and L2 signals, after demodulation by locally generated carrier and P-code signals, is repetitively accomplished over a duration that is estimated to be the period of the modulation code. The C/A-code L1 signal, which is not modulated with the unknown security code, is also used in locking the locally generated carrier and P-code generators in phase with the received L1 and L2 satellite signals. An interpolative technique is used for adjusting the phase of the locally generated carriers and code in increments much smaller than the period clock sources. Those locked phases can then be utilized to determine position, distance, time, etc., as is done in GPS receivers not utilizing the anti-spoofed signals but with increased accuracy and resolution.Type: GrantFiled: April 10, 1991Date of Patent: July 28, 1992Assignee: Ashtech Telesis, Inc.Inventors: Robert G. Lorenz, Roger J. Helkey, Kamran K. Abadi
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Patent number: 4928106Abstract: A global positioning system (GPS) receiver having a common radio frequency section and a separate digital signal processing channel for each of a plurality of satellite signals which are simultaneously being received and processed by the receiver in order to calculate the position, velocity or other desired parameters of the receiver. The radio frequency section receives and processes both of the standard satellite signals on different frequency L1 and L2 carriers in order to provide the multi-channel digital section signals from which the relative phase of the carriers from each of the plurality of satellites may be determined. Particular mutually coherent local oscillator and digital clock frequencies are selected in order to minimize the complexity of the receiver without creating any undesired side effects.Type: GrantFiled: July 14, 1988Date of Patent: May 22, 1990Assignee: Ashtech Telesis, Inc.Inventors: Javad Ashjaee, Roger J. Helkey, Robert G. Lorenz, Robert A. Sutherland