Patents by Inventor Carl R. Davidson
Carl R. Davidson 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: 20240027260Abstract: A system may include a distributed acoustic sensing (DAS) station, comprising a DAS transmitter to launch an outbound DAS signal in a first direction, over at least one span of an optical communications link. The system may further include a DAS receiver to receive a backscattered Rayleigh signal, based upon the outbound DAS signal, wherein the DAS signal is transmitted at least in part over a D? fiber.Type: ApplicationFiled: July 20, 2023Publication date: January 25, 2024Applicant: SUBCOM, LLCInventors: Jin-Xing CAI, Carl R. DAVIDSON, William W. PATTERSON, Alexei N. PILIPETSKII
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Publication number: 20240027261Abstract: A distributed acoustic sensing system. The DAS system may include a distributed acoustic sensing (DAS) station, comprising: a DAS transmitter, arranged to launch an outbound DAS signal through an optical fiber, over at least one span; a DAS receiver, arranged to receive a backscatter Rayleigh signal, based upon the DAS signal; and at least one component, coupled to the DAS transmitter, the DAS receiver, or both, and arranged to increase a sensitivity for sensing of the DAS system.Type: ApplicationFiled: July 20, 2023Publication date: January 25, 2024Applicant: SUBCOM, LLCInventors: Jin-Xing CAI, Carl R. DAVIDSON, William W. PATTERSON, Alexei N. PILIPETSKII
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Publication number: 20240027259Abstract: A sensing system may include a distributed acoustic sensing (DAS) station to launch a DAS signal as an outbound DAS signal, as well as a plurality of DAS loopback assemblies, arranged along a plurality of spans. The plurality of DAS loopback assemblies may be arranged to separately process the outbound DAS signal, and return to the DAS station, the outbound DAS signal, as a return DAS signal that comprises a backscattered Rayleigh signal. As such, a given DAS loopback assembly of the plurality of DAS loopback assemblies may include an Erbium-Doped Fiber Amplifier (EDFA) that is arranged to compensate the loss from Rayleigh scattering of the DAS signal, and a filter device having an optical filtering function that is arranged to selectively send back just a sensing wavelength of the DAS signal.Type: ApplicationFiled: July 20, 2023Publication date: January 25, 2024Applicant: SUBCOM, LLCInventors: Jin-Xing CAI, Carl R. DAVIDSON, William W. PATTERSON, Alexei N. PILIPETSKII
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Patent number: 8805204Abstract: In general, optical communication systems and methods may generate higher-level nmQAM from nQAM signals using one or more delay line interferometers (DLIs) arranged in various configurations. The nQAM signals may be generated by a lower-level modulator, such as a BPSK modulator, QPSK modulator or lower-level QAM modulator, with binary driving signals. Different parameters of the DLIs, such as free spectral range (FSR), phase shift, and amplitude imbalance, may be selected to accomplish the desired higher-level nmQAM depending upon the nQAM signal.Type: GrantFiled: February 23, 2011Date of Patent: August 12, 2014Assignee: Tyco Electronics Subsea Communications LLCInventors: Hongbin Zhang, Jin-Xing Cai, Yu Sun, Carl R. Davidson, Yi Cai, Georg Heinrich Mohs
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Patent number: 8437644Abstract: In general, optical communication systems and methods may implement a vestigial phase shift keying (PSK) modulation format to enable relatively high transmission rates with closer channel spacing and improved signal detection in a WDM optical communication system. A PSK modulated signal may be correlated with a phase shift, for example, using a delay line interferometer (DLI), to generate a vestigial PSK signal, which may be pre-filtered, combined, and transmitted in the WDM system. The correlation with a phase shift compresses and shifts the signal spectrum such that intersymbol interference (ISI) length may be reduced with minimal increase in the bit error rate (BER) when the vestigial PSK signal is detected.Type: GrantFiled: February 23, 2011Date of Patent: May 7, 2013Assignee: Tyco Electronics Subsea Communications LLCInventors: Hongbin Zhang, Carl R. Davidson, Jin-Xing Cai, Yi Cai
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Publication number: 20120213522Abstract: In general, optical communication systems and methods may generate higher-level nmQAM from nQAM signals using one or more delay line interferometers (DLIs) arranged in various configurations. The nQAM signals may be generated by a lower-level modulator, such as a BPSK modulator, QPSK modulator or lower-level QAM modulator, with binary driving signals. Different parameters of the DLIs, such as free spectral range (FSR), phase shift, and amplitude imbalance, may be selected to accomplish the desired higher-level nmQAM depending upon the nQAM signal.Type: ApplicationFiled: February 23, 2011Publication date: August 23, 2012Applicant: TYCO ELECTRONICS SUBSEA COMMUNICATIONS LLCInventors: Hongbin Zhang, Jin-Xing Cai, Yu Sun, Carl R. Davidson, Yi Cai, Georg Heinrich Mohs
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Publication number: 20120213521Abstract: In general, optical communication systems and methods may implement a vestigial phase shift keying (PSK) modulation format to enable relatively high transmission rates with closer channel spacing and improved signal detection in a WDM optical communication system. A PSK modulated signal may be correlated with a phase shift, for example, using a delay line interferometer (DLI), to generate a vestigial PSK signal, which may be pre-filtered, combined, and transmitted in the WDM system. The correlation with a phase shift compresses and shifts the signal spectrum such that intersymbol interference (ISI) length may be reduced with minimal increase in the bit error rate (BER) when the vestigial PSK signal is detected.Type: ApplicationFiled: February 23, 2011Publication date: August 23, 2012Applicant: TYCO ELECTRONICS SUBSEA COMMUNICATIONS LLCInventors: Hongbin Zhang, Carl R. Davidson, Jin-Xing Cai, Yi Cai
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Patent number: 8090270Abstract: An apparatus, system and method wherein a polarization multiplexed differential phase shift keying format (POLMUX-DPSK) is provided with offset and bit-interleaved frequency channels and demodulated using a DPSK demodulator.Type: GrantFiled: August 6, 2008Date of Patent: January 3, 2012Assignee: Tyco Electronics Subsea Communications LLCInventors: Hongbin Zhang, Carl R. Davidson
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Patent number: 7778550Abstract: A system and method using for wavelength monitoring and control in a WDM optical communication system. An aggregate channel monitor detects crosstalk between channels in the aggregate signal. Channel spacing may be modified by an element management system in response to the output of the aggregate channel monitor.Type: GrantFiled: July 27, 2007Date of Patent: August 17, 2010Assignee: Tyco Electronics Subsea Communications LLCInventors: Hongbin Zhang, Ralph Brian Jander, Carl R Davidson
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Publication number: 20100034537Abstract: An apparatus, system and method wherein a polarization multiplexed differential phase shift keying format (POLMUX-DPSK) is provided with offset and bit-interleaved frequency channels and demodulated using a DPSK demodulator.Type: ApplicationFiled: August 6, 2008Publication date: February 11, 2010Applicant: TYCO TELECOMMUNICATIONS (US) INC.Inventors: Hongbin Zhang, Carl R. Davidson
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Publication number: 20090028552Abstract: A system and method using for wavelength monitoring and control in a WDM optical communication system. An aggregate channel monitor detects crosstalk between channels in the aggregate signal. Channel spacing may be modified by an element management system in response to the output of the aggregate channel monitor.Type: ApplicationFiled: July 27, 2007Publication date: January 29, 2009Applicant: TYCO TELECOMMUNICATIONS (US) INC.Inventors: Hongbin Zhang, Ralph Brian Jander, Carl R. Davidson
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Patent number: 7373040Abstract: A WDM optical transmission system and method uses slope compensation at the transmit terminal and/or the receive terminal. The system and method may be used with modulation formats with a short pulse width and a broad optical spectrum.Type: GrantFiled: April 13, 2007Date of Patent: May 13, 2008Assignee: Tyco Telecommunications (US) Inc.Inventors: Jin-Xing Cai, Dmitri Foursa, Carl R. Davidson, Alexei N. Pilipetskii, Morten Nissov, Neal S. Bergano
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Publication number: 20070274728Abstract: An optical communication system and method may be configured to operate with optical signals having reduced channel spacing. The system may transmit optical signals on a plurality of optical channels with a pair-wise orthogonal relationship such that a first subset of channels has a first polarization state and a second subset of channels has a second polarization state. The channels may be spaced such that there is no overlap of modulation sidebands associated with channels in each of the polarization states. When receiving the optical signals, the orthogonal channels adjacent to a selected channel of interest may be nulled.Type: ApplicationFiled: May 26, 2006Publication date: November 29, 2007Inventors: Neal S. Bergano, Chien-Jen Chen, Carl R. Davidson
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Patent number: 7295728Abstract: A WDM optical transmission system and method uses slope compensation at the transmit terminal and/or the receive terminal. The system and method may be used with modulation formats with a short pulse width and a broad optical spectrum.Type: GrantFiled: February 27, 2006Date of Patent: November 13, 2007Assignee: Tyco Telecommunications (US) Inc.Inventors: Jin-Xing Cai, Dmitri Foursa, Carl R. Davidson, Alexei N. Pilipetskii, Morten Nissov, Neal S. Bergano
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Patent number: 7256877Abstract: A system and method for optimizing dispersion in an optical transmission line is provided. The system and method comprise measuring the amplitude of a d.c. voltage component of a synchronously demodulated data signal of at least one wavelength channel by an in-phase carrier at the baud frequency of the wavelength channel. In an alternative embodiment, the system and method comprise measuring the IF amplitude of the resulting a.c. signal of a data signal of the at least one wavelength channel comprising a received RZ signal mixed with a local oscillator, whose frequency differs from the wavelength channel baud by a relatively small amount, somewhere on the order of about 100 kHz.Type: GrantFiled: January 26, 2006Date of Patent: August 14, 2007Assignee: Tyco Telecommunications (US) Inc.Inventors: Robert R. Cordell, Carl R. Davidson, Yi Cai, Hongbin Zhang
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Patent number: 7130030Abstract: A system and method for optimizing dispersion in an optical transmission line is provided. The system and method comprise measuring the amplitude of a d.c. voltage component of a synchronously demodulated data signal of at least one wavelength channel by an in-phase carrier at the baud frequency of the wavelength channel. In an alternative embodiment, the system and method comprise measuring the IF amplitude of the resulting a.c. signal of a data signal of the at least one wavelength channel comprising a received RZ signal mixed with a local oscillator, whose frequency differs from the wavelength channel baud by a relatively small amount, somewhere on the order of about 100 kHz.Type: GrantFiled: October 2, 2003Date of Patent: October 31, 2006Assignee: Tyco Telecommunications (US) Inc.Inventors: Carl R. Davidson, Robert R. Cordell, Yi Cai, Hongbin Zhang
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Publication number: 20040141172Abstract: A system and method for optimizing dispersion in an optical transmission line is provided. The system and method comprise measuring the amplitude of a d.c. voltage component of a synchronously demodulated data signal of at least one wavelength channel by an in-phase carrier at the baud frequency of the wavelength channel. In an alternative embodiment, the system and method comprise measuring the IF amplitude of the resulting a.c. signal of a data signal of the at least one wavelength channel comprising a received RZ signal mixed with a local oscillator, whose frequency differs from the wavelength channel baud by a relatively small amount, somewhere on the order of about 100 kHz.Type: ApplicationFiled: October 2, 2003Publication date: July 22, 2004Applicant: Tyco Telecommunications (US) Inc.Inventors: Carl R. Davidson, Robert R. Cordell, Yi Cai, Hongbin Zhang
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Patent number: 6134033Abstract: A method and apparatus is provided for transmitting an optical signal. The method includes the step of generating an optical signal that includes a plurality of optical channels, which are sequentially numbered from 1 to N from lowest to highest wavelength. A state-of-polarization of predetermined odd-numbered channels is oriented to be substantially orthogonal to a state of polarization of predetermined even-numbered channels by directing the predetermined odd-numbered channels and the predetermined even-numbered channels through orthogonally polarizing inputs of a polarization coupler. The odd-numbered channels and the even-numbered channels may be directed through first and second wavelength combiners, respectively, prior to orienting their states of polarization.Type: GrantFiled: February 26, 1998Date of Patent: October 17, 2000Assignee: Tyco Submarine Systems Ltd.Inventors: Neal S. Bergano, Carl R. Davidson
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Patent number: 5946119Abstract: An apparatus is provided for transmitting an optical signal. The apparatus includes an optical signal source for generating an optical signal having a plurality of optical channels onto which data is modulated at a plurality of predetermined frequencies to provide a plurality of optical data channels. An amplitude modulator is coupled to the optical signal source for modulating each of the optical channels with a waveform that is independently adjustable from one another. A clock, coupled to the amplitude modulator, has a plurality of frequencies that respectively determine the modulation frequencies imparted to the plurality of optical channels by the amplitude modulator. Each of the frequencies of the clock is phase locked and equal to its respective predetermined frequency at which is data is modulated.Type: GrantFiled: February 12, 1997Date of Patent: August 31, 1999Assignee: Tyco Submarine Systems Ltd.Inventors: Neal S. Bergano, Carl R. Davidson, Stephen G. Evangelides, Jr.