Patents by Inventor Jonathan A. Nagel

Jonathan A. Nagel 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).

  • Patent number: 6768875
    Abstract: Methods and systems for PMD compensation in an optical communication system are implemented by transmitting multiple optical signals through a common optical conduit to an optical compensator that adjustably rotates the polarization states of the multiple optical signals and transmits the rotated optical signals to an optical receiver. The receiver, upon sensing an excessive error condition, commands the optical compensator to change the polarization state of rotation, which changes the PMD profile of the received optical signals.
    Type: Grant
    Filed: December 1, 2000
    Date of Patent: July 27, 2004
    Assignee: AT&T Corp.
    Inventors: Michael Herbert Eiselt, Jonathan A. Nagel
  • Publication number: 20040136056
    Abstract: An optical repeater is provided that includes at least four optical amplifiers each supplying optical amplification to an optical signal traveling in a different unidirectional optical fiber that collectively form at least two bi-directional pairs of optical fibers. The repeater also includes a first plurality of pump sources for providing pump energy to a first optical fiber located in a first of the optical fiber pairs and a second optical fiber located in a second of the optical fiber pairs. The first optical fiber and the second optical fiber support optical signals traveling in a common direction. A first combiner arrangement combines the pump energy from the first plurality of pump sources and distributes it to the optical amplifiers supplying amplification to optical signals traveling in the first and the second optical fibers.
    Type: Application
    Filed: August 20, 2003
    Publication date: July 15, 2004
    Inventors: Jonathan A. Nagel, Michael J. Neubelt
  • Publication number: 20040126119
    Abstract: An optical transmission system has an optical transmission terminal with first and second optical interfaces. The first interface is configured to communicate in accordance with an industry-standard, network level protocol. The second interface is configured to communicate in accordance with a first optical layer transport protocol. The optical transmission span includes an optical interface device that has a third interface communicating with the second interface of the optical transmission terminal in accordance with the first optical layer transport protocol and a fourth interface configured to communicate in accordance with a second optical layer transport protocol. The optical interface device also has a signal processing unit for transforming optical signals between the first and second optical layer transport protocols.
    Type: Application
    Filed: July 16, 2003
    Publication date: July 1, 2004
    Inventors: Stephen G. Evangelides, Jay P. Morreale, Michael J. Neubelt, Mark K. Young, Jonathan A. Nagel
  • Publication number: 20040096215
    Abstract: An optical transmission system has an optical transmission terminal with first and second optical interfaces. The first interface is configured to communicate in accordance with an industry-standard, network level protocol. The second interface is configured to communicate in accordance with a first optical layer transport protocol. The optical transmission span includes an optical interface device that has a third interface communicating with the second interface of the optical transmission terminal in accordance with the first optical layer transport protocol and a fourth interface configured to communicate in accordance with a second optical layer transport protocol. The optical interface device also includes a signal processing unit for transforming optical signals between the first and second optical layer protocols. A test system is coupled to the signal processing unit for monitoring optical signal quality.
    Type: Application
    Filed: July 16, 2003
    Publication date: May 20, 2004
    Inventors: Stephen G. Evangelides, Jay P. Morreale, Michael J. Neubelt, Mark K. Young, Jonathan A. Nagel
  • Publication number: 20040036959
    Abstract: In an optical communication system that includes a transmitting terminal, a receiving terminal, and an optical transmission path optically coupling the transmitting and receiving terminals and having at least one rare-earth doped optical amplifier therein, a second optical amplifier is provided The second optical amplifier includes a first portion of the optical transmission path having a first end coupled to the transmitting terminal and a second end coupled to a first of the rare-earth doped optical amplifiers. In addition, the second optical amplifier includes a pump source providing pump energy to the first portion of the optical transmission path at one or more wavelengths that is less than a signal wavelength to provide Raman gain in the first portion at the signal wavelength.
    Type: Application
    Filed: December 6, 2002
    Publication date: February 26, 2004
    Inventors: Stephen G. Evangelides, Jonathan A. Nagel, Mark K. Young
  • Patent number: 6690504
    Abstract: A system and method for controlling gain shape in a Raman amplifier including a plurality of pumps. The pumps produce a spectral distribution of output power characteristic. A feedback control system provides one or more feedback control signals in response to the amplifier output for adjusting pump parameters to achieve a desired spectral distribution of output power characteristic.
    Type: Grant
    Filed: March 14, 2002
    Date of Patent: February 10, 2004
    Assignee: Tyco Telecommunications (US) Inc.
    Inventors: Jonathan A. Nagel, Sergey Y. Ten, Carl A. B. Clausen
  • Patent number: 6674972
    Abstract: Methods and systems for higher-order PMD compensation are implemented by developing an effective mathematical model and applying economical design techniques to the model. By assuming a constant precession rate for a narrow band of frequencies in an optical signal, a simplified model of a higher-order PMD compensator can be derived. The model can be used produce an economical compensator by making multiple uses of selected optical components.
    Type: Grant
    Filed: August 29, 2000
    Date of Patent: January 6, 2004
    Assignee: AT&T Corp.
    Inventors: Antonio Mecozzi, Jonathan A. Nagel, Mark Shtaif, Moshe Tur
  • Publication number: 20020131131
    Abstract: An optical communication system including a transmitter, an optical information channel, and a receiver. The transmitter is configured to transmit a plurality of optical signals in L-band wavelengths or between about 1560 nm and about 1630 nm. Use of the L-band in long-haul optical systems permits transmission over at least about 2,000 kilometers from an originating light source such as a transmitter or another regenerator. A method of modulating and transmitting data signals in the L-band is also provided.
    Type: Application
    Filed: October 17, 2001
    Publication date: September 19, 2002
    Inventors: Jonathan A. Nagel, Sergey Y. Ten, Carl A. B. Clausen
  • Patent number: 5822113
    Abstract: An optical amplifier achieves multistage amplification with a four port optical circulator with fiber amplifiers and Faraday rotators and mirrors connected to at least two of the ports. The fiber amplifiers permit the signal to pass through the fiber amplifiers twice.
    Type: Grant
    Filed: December 16, 1996
    Date of Patent: October 13, 1998
    Assignee: Lucent Technologies Inc.
    Inventors: Jean-Marc Pierre Delavaux, Jonathan A. Nagel
  • Patent number: 5481399
    Abstract: The present invention is an in-line multi-stage erbium doped fiber amplifier system for use in fiber optic communication systems. The system comprises two cascaded erbium doped fiber amplifiers (12), (14) separated by an drop/add device (20) for filtering out the amplifier spontaneous emission noise and the existing telemetry channel and for adding a new telemetry channel before the second amplifier (14). The invention also provides a method for providing a telemetry signal to in-line erbium doped fiber amplifier sites without affecting the signal capacity of the system, and also provides a method for monitoring the performance of a link in an optical fiber communication system.
    Type: Grant
    Filed: January 3, 1995
    Date of Patent: January 2, 1996
    Assignee: AT&T Corp.
    Inventors: Jonathan A. Nagel, Samia M. Bahsoun
  • Patent number: 5430572
    Abstract: High output power, high gain, and low noise are achieved in a two-stage optical amplifier, suitable for use as a repeater for a long haul lightwave communication system, in accordance with the principles of the invention, by employing a first amplifying stage having a signal gain sufficiently small to prevent self-saturation by amplified stimulated emission (ASE) that uses counter-propagating pump light to cause maximum inversion of the first stage amplifying medium. In an illustrative embodiment of the invention, EDFAs are used in each of two amplifying stages. The length of the EDFA in the first stage is short enough to ensure nearly complete inversion of the EDFA from pump light that counter-propagates with the signal. The counter-propagating pump light allows the invention to advantageously avoid the significant noise figure penalty from the input loss associated with co-propagating pump light.
    Type: Grant
    Filed: September 30, 1993
    Date of Patent: July 4, 1995
    Assignee: AT&T Corp.
    Inventors: David J. DiGiovanni, Joseph D. Evankow, Jonathan A. Nagel, Richard G. Smart, James W. Sulhoff, John L. Zyskind
  • Patent number: 5406404
    Abstract: The present invention relates to a method of mitigating gain peaking in a chain of fiber amplifiers by pumping the amplifiers at a predetermined wavelength to produce gain over a specified wavelength range.
    Type: Grant
    Filed: November 2, 1993
    Date of Patent: April 11, 1995
    Assignee: AT&T Corp.
    Inventors: David J. DiGiovanni, Jonathan A. Nagel, Richard G. Smart, James W. Sulhoff, John L. Zyskind
  • Patent number: 5394265
    Abstract: The present invention is an in-line multi-stage erbium doped fiber amplifier system for use in fiber optic communication systems. The system comprises two cascaded erbium doped fiber amplifiers (12), (14) separated by an drop/add device (20) for filtering out the amplifier spontaneous emission noise and the existing telemetry channel and for adding a new telemetry channel before the second amplifier (14). The invention also provides a method for providing a telemetry signal to in-line erbium doped fiber amplifier sites without affecting the signal capacity of the system, and also provides a method for monitoring the performance of a link in an optical fiber communication system.
    Type: Grant
    Filed: October 25, 1993
    Date of Patent: February 28, 1995
    Assignee: AT&T Corp.
    Inventors: Jonathan A. Nagel, Samia M. Bahsoun
  • Patent number: 5329396
    Abstract: A technique for reducing the power threshold at which stimulated brillouin scattering ("SBS") occurs within an optical fiber by directly modulating a conventional laser generating an optical signal propagated along that fiber. The modulation is accomplished by employing an alternating waveform to induce a dither upon the laser output. The specific frequency of the alternating waveform is chosen to be very much lower than the low frequency cut-off of any receiver coupled to the optical fiber, but sufficiently high enough to efficiently suppress the Brillouin gain. This dithering causes the laser to be frequency modulated, thereby broadening the effective linewidth of the laser output and increasing the SBS power threshold.
    Type: Grant
    Filed: October 28, 1992
    Date of Patent: July 12, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Daniel A. Fishman, Jonathan A. Nagel, Yong-Kwan Park
  • Patent number: 5225922
    Abstract: Increasing the capacity of an existing lightwave transmission system can be accomplished by either increasing the bit rate or adding wavelength-multiplexed channels. Recent advances in erbium-doped fiber amplifier technology make the wavelength division multiplexed option particularly attractive. Unfortunately, because of nonuniform wavelength-dependent gain profile and saturation characteristic of erbium-doped fiber amplifiers, each channel of a wavelength-multiplexed system will experience a different optical gain which, in turn, can result in an excessive bit-error-rate performance in some channels. This invention is directed toward processing apparatus which selectively equalizes the optical gain or the optical signal-to-noise ratios of the channels of a wavelength-multiplexed optical transmission system. The output powers and the signal-to-noise ratios are selectively equalized by adjusting the optical input signal powers.
    Type: Grant
    Filed: November 21, 1991
    Date of Patent: July 6, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Andrew R. Chraplyvy, Jonathan A. Nagel, Robert W. Tkach