Patents by Inventor Robert G. Waarts

Robert G. Waarts 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).

  • Publication number: 20030076577
    Abstract: A lossless optical link in an optical transmission system comprises an optical fiber that is configured to produce Raman gain and provide for Raman distributed gain, via one or more pump sources, along the fiber so that, as an end result, the gain experienced by one or more propagating signals in the fiber link is made fairly uniform along the link or at least a portion of the optical link, such as not vary, for example, no more than five dB along the length of the optical fiber. The several embodiments disclosed provide for different optical pump/component architectures to achieve this end result.
    Type: Application
    Filed: December 22, 2000
    Publication date: April 24, 2003
    Inventors: Vincent G. Dominic, David F. Welch, Robert G. Waarts, Stuart MacCormack, Mehrdad Ziari, Robert J. Lang, Donald R. Scifres
  • Patent number: 6483974
    Abstract: An optical fiber gain medium has a core region in which a signal propagates, and a cladding region surrounding the core into which a pump signal is coupled. The gain medium also includes a plurality of doped regions each of which has a different effect on the gain profile of the gain medium. In a first embodiment, two doped regions are located in the cladding region at different radial distances from the core. Each of the two doped regions has a different absorption characteristic such that it absorbs signal energy in a different wavelength region of the gain band. The relative contributions may be controlled by controlling a number of different factors, including type of dopant, density of dopant, radial width of the doped regions, and relative separation between the doped regions, and their positioning relative to evanescent portions of different wavelength bands.
    Type: Grant
    Filed: October 24, 2000
    Date of Patent: November 19, 2002
    Assignee: JDS Uniphase Corporation
    Inventor: Robert G. Waarts
  • Patent number: 6477295
    Abstract: Apparatus for coupling light into a fiber, such as a double clad fiber (DCF) having a core having a refractive index n1, surrounded by an inner cladding having refractive index n2 which is surrounded by an outer cladding having a refractive index n3, where n1>n2>n3. An optical coupler medium, referred to as a Fiber Space Division Multiplexor or FSDM, is formed on an exposed portion of the fiber inner cladding at a position along the length of the fiber without interfering with the continuity of its core and provides at, at least one position, the imaging of light external of the fiber into the inner cladding interface and its waveguiding with the inner cladding of the fiber. The FSDM coupler comprises an optical material in optical contact or integrated with the inner cladding and having a refractive index substantially equal to n2. The coupler medium may also be employed with a fiber having no core and where the inner cladding would function as a multimode core.
    Type: Grant
    Filed: January 20, 2000
    Date of Patent: November 5, 2002
    Assignee: JDS Uniphase Corporation
    Inventors: Robert J. Lang, Robert G. Waarts, Ian J. Booth, David M. Giltner, Steven Sanders
  • Patent number: 6434295
    Abstract: All-fiber coupling architectures include at least one fiber gain media, e.g. a fiber amplifier or a fiber laser, providing for the coupling light from one or more multi-wavelength pump sources propagating in a multimode core fiber at multiple points along a double clad fiber or at least at one point along multiple double clad fibers having their inner claddings fused to the multimode core fiber. The latter arrangement provides for a low cost utility multi-signal fiber amplifier for telecommunication applications.
    Type: Grant
    Filed: January 13, 2000
    Date of Patent: August 13, 2002
    Assignee: JDS Uniphase Corporation
    Inventors: Stuart MacCormack, Vincent G. Dominic, Robert G. Waarts
  • Patent number: 6411323
    Abstract: Power scaling by multiplexing multiple fiber gain sources with different wave-lengths is useful in printing applications requiring higher optical powers to perform the printing function, such as through thermal inducement in thermal ablation, thermal fusion, thermal diffusion or thermal transfer. A marking system is disclosed using a plurality of laser sources operating at different wavelengths with their respective outputs coupled into a respective single mode fiber. At least one WDM combiner is coupled to receive and combine the laser source outputs into a single output. The combined power single output provides sufficient power intensity to induce thermal marking on a marking medium.
    Type: Grant
    Filed: December 7, 2000
    Date of Patent: June 25, 2002
    Assignee: SDL, Inc.
    Inventors: Robert G. Waarts, David F. Welch
  • Patent number: 6407855
    Abstract: Optical pumping arrangements are provided for the broadband or multiple wavelength pumping of optical sources. Sources may be based on Raman gain media and may use multiple output couplers to couple out different wavelength ranges. Cascaded Raman resonator (CRR) configurations may also be used. Overlapping resonators at different wavelengths may be configured to share gain media, and may have separate portions in separate optical paths. Attenuation filters may also be used that are matched to the gain profile of a gain medium, to flatten the gain spectrum and allow equalization of gain to different output wavelengths. In one embodiment, polarization maintaining fiber is used to develop resonant conditions at different wavelengths in different polarization states. Wideband output gratings may be substituted for narrowband gratings to provide CRR configurations with a broader output band. Broadband amplification may also be provided by using a laser source operating in coherence collapse.
    Type: Grant
    Filed: October 29, 1999
    Date of Patent: June 18, 2002
    Assignee: SDL, Inc.
    Inventors: Stuart MacCormack, David M. Giltner, Vincent G. Dominic, Donald R. Scifres, Bardia Pezeshki, Edward C. Vail, Mehrdad Ziari, Robert G. Waarts
  • Patent number: 6330257
    Abstract: The effectiveness of reflected light to stabilize the operational characteristics of a semiconductor diode laser varies with the polarization orientation of the reflected light. Stabilization failure can occur if the polarization orientation of the reflected light is orthogonal to the polarization of the light emitted by the laser source. The use of multiple reflectors can reduce the probability of stabilization failure by arranging the reflectors to return to the laser source portions of light having polarization orientations that are statistically independent with respect to each other.
    Type: Grant
    Filed: August 4, 1999
    Date of Patent: December 11, 2001
    Assignee: SDL, Inc.
    Inventors: Jo S. Major, Jr., Garnet Luick, Ian J. Booth, David C. Dawson, Fritz Christo, Robert G. Waarts
  • Patent number: 6301271
    Abstract: A frequency conversion system comprises first and second gain sources providing first and second frequency radiation outputs where the second gain source receives as input the output of the first gain source and, further, the second gain source comprises a Raman or Brillouin gain fiber for wave shifting a portion of the radiation of the first frequency output into second frequency radiation output to provided a combined output of first and second frequencies. Powers are gain enhanced by the addition of a rare earth amplifier or oscillator, or a Raman/Brillouin amplifier or oscillator between the high power source and the NFM device. Further, polarization conversion using Raman or Brillouin wavelength shifting is provided to optimize frequency conversion efficiency in the NFM device.
    Type: Grant
    Filed: December 11, 2000
    Date of Patent: October 9, 2001
    Assignee: SDL, Inc.
    Inventors: Steven Sanders, Robert G. Waarts
  • Patent number: 6301273
    Abstract: A frequency conversion system includes at least one source providing a first near-IR wavelength output including a gain medium for providing high power amplification, such as double clad fiber amplifier, a double clad fiber laser or a semiconductor tapered amplifier to enhance the power output level of the near-IR wavelength output. The NFM device may be a difference frequency mixing (DFM) device or an optical parametric oscillation (OPO) device. Pump powers are gain enhanced by the addition of a rare earth amplifier or oscillator, or a Ra-man/Brillouin amplifier or oscillator between the high power source and the NFM device.
    Type: Grant
    Filed: December 11, 2000
    Date of Patent: October 9, 2001
    Assignee: SDL, Inc.
    Inventors: Steven Sanders, Robert J. Lang, Robert G. Waarts
  • Patent number: 6298187
    Abstract: Power scaling by multiplexing multiple fiber gain sources with different wavelengths, pulsing or polarization modes of operation is achieved through multiplex combining of the multiple fiber gain sources to provide high power outputs, such as ranging from tens of watts to hundreds of watts, provided on a single mode or multimode fiber.
    Type: Grant
    Filed: November 14, 2000
    Date of Patent: October 2, 2001
    Assignee: SDL, Inc.
    Inventors: Robert G. Waarts, David F. Welch, Stephen G. Grubb, Jean-Luc Archambault, Donald R. Scifres
  • Patent number: 6282016
    Abstract: A number of variations are provided of a device that provides an amplified single polarization optical signal. Each of these relies on the use of a non-polarization maintaining gain medium through which the signal is directed, and a polarization shifter and reflector that direct the signal back through the same gain medium with a shifted polarization state. An input polarization beamsplitter directs the returning optical signal away to an output, based on its shifted polarization state. The embodiments of the invention include the use of double-clad fiber. Multiple stages may be used to provide specific amplification parameters. In particular, a fiber with a relatively large mode field diameter may be used to enable high pulse power applications. Wavelength selective components are used in certain embodiments of the invention, to allow for wavelength selectivity, as well as a single polarization state, in amplifiers, lasers and amplified spontaneous emission (ASE).
    Type: Grant
    Filed: December 1, 1999
    Date of Patent: August 28, 2001
    Assignee: SDL, Inc.
    Inventors: Stuart MacCormack, Robert G. Waarts, Paul Freeman, Stephen G. Grubb
  • Patent number: 6275632
    Abstract: Power scaling by multiplexing multiple fiber gain sources with different wavelengths, pulsing or polarization modes of operation is achieved through multiplex combining of the multiple fiber gain sources to provide high power outputs, such as ranging from tens of watts to hundreds of watts, provided on a single mode or multimode fiber.
    Type: Grant
    Filed: November 25, 2000
    Date of Patent: August 14, 2001
    Assignee: SDL, Inc.
    Inventors: Robert G. Waarts, David F. Welch, Stephen G. Grubb, Jean-Luc Archambault, Steven Sanders, Raymond Zanoni, Donald R. Scifres
  • Patent number: 6229828
    Abstract: Laser diode pumped mid-IR wavelength sources include at least one high power, near-IR wavelength, injection and/or sources wherein one or both of such sources may be tunable providing a pump wave output beam to a quasi-phase matched (QPM) nonlinear frequency mixing (NFM) device. The NFM device may be a difference frequency mixing (DFM) device or an optical parametric oscillation (OPO) device. Wavelength tuning of at least one of the sources advantageously provides the ability for optimizing pump or injection wavelengths to match the QPM properties of the NFM device enabling a broad range of mid-IR wavelength selectivity. Also, pump powers are gain enhanced by the addition of a rare earth amplifier or oscillator, or a Raman/Brillouin amplifier or oscillator between the high power source and the NFM device. Further, polarization conversion using Raman or Brillouin wavelength shifting is provided to optimize frequency conversion efficiency in the NFM device.
    Type: Grant
    Filed: July 27, 1998
    Date of Patent: May 8, 2001
    Assignee: SDL, Inc.
    Inventors: Steven Sanders, Robert J. Lang, Robert G. Waarts
  • Patent number: 6222864
    Abstract: Coherent light sources combining a semiconductor optical source with a light diverging region, such as a flared resonator type laser diode or flared amplifier type MOPA, with a single lens adapted to correct the astigmatism of the light beam emitted from the source is disclosed. The lens has an acircular cylindrical or toroidal first surface and an aspheric or binary diffractive second surface. The first surface has a curvature chosen to substantially equalize the lateral and transverse divergences of the astigmatic beam. Sources with an array of light diverging regions producing an array of astigmatic beams and a single astigmatism-correcting lens array aligned with the beams are also disclosed. The single beam source can be used in systems with frequency converting nonlinear optics. The array source can be stacked with other arrays to produce very high output powers with high brightness.
    Type: Grant
    Filed: May 7, 1998
    Date of Patent: April 24, 2001
    Assignee: SDL, Inc.
    Inventors: Robert G. Waarts, Robert J. Lang, Julian S. Osinski, Edmund L. Wolak, John Endriz
  • Patent number: 6215809
    Abstract: Apparatus for providing a laser source optically coupled to an optical waveguide, such as an optical fiber, having a reflective grating positioned from the output facet of the laser source a distance equal to or greater than the coherence length of the laser source providing a portion of reflective feedback into the laser source optical cavity to maintain wavelength operation of the laser source in spite of changes in the laser operating temperature or drive current based upon coherence collapse in the laser operation. In cases where the fiber grating is positioned in the fiber within the coherence length of the laser source, intermittent coherence collapse, as opposed to continuous coherence collapse, is unavoidable. In cases where such a laser source is a pumping source for a solid state gain medium, such as an optical amplifier or laser having an active gain element, e.g.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: April 10, 2001
    Assignee: SDL, Inc.
    Inventors: Mehrdad Ziari, Robert G. Waarts, Robert J. Lang, John DeAndrea, Michael L. Bortz, Brian F. Ventrudo
  • Patent number: 6212310
    Abstract: Power scaling by multiplexing multiple fiber gain sources with different wavelengths, pulsing or polarization modes of operation is achieved through multiplex combining of the multiple fiber gain sources to provide high power outputs, such as ranging from tens of watts to hundreds of watts, provided on a single mode or multimode fiber.
    Type: Grant
    Filed: October 21, 1997
    Date of Patent: April 3, 2001
    Assignee: SDL, Inc.
    Inventors: Robert G. Waarts, David F. Welch, Stephen G. Grubb, Jean-Luc Archambault, Steven Sanders, Raymond Zanoni, Donald R. Scifres
  • Patent number: 6181465
    Abstract: An optical fiber used as the active amplifying medium in a fiber laser is arranged to have a high insertion loss at an undesired frequency, while retaining a low insertion loss at a desired lasing frequency. In one embodiment, loss at a Raman-shifted frequency is introduced by using an optical fiber which has multiple claddings with an index profile that includes an elevated index region located away from the core, but within the evanescent coupling region of the core. A distributed loss, which can be enhanced by bending, is produced at the Raman frequency which effectively raises the threshold at which Raman scattering occurs in the fiber and therefore results in a frequency-selective fiber. In another embodiment, an absorbing layer is placed around the core region. The absorbing layer is chosen to have a sharp absorption edge so that it absorbs highly at the Raman-shifted wavelength, but minimally at the desired lasing wavelength.
    Type: Grant
    Filed: April 5, 1999
    Date of Patent: January 30, 2001
    Assignee: SDL, Inc.
    Inventors: Stephen G. Grubb, Raymond Zanoni, Robert G. Waarts, Jean-Luc Archambault
  • Patent number: 6118575
    Abstract: An optical fiber used as the active amplifying medium in a fiber laser is arranged to have a high insertion loss at an undesired frequency, while retaining a low insertion loss at a desired lasing frequency. In one embodiment, loss at a Raman-shifted frequency is introduced by using an optical fiber which has multiple claddings with an index profile that includes an elevated index region located away from the core, but within the evanescent coupling region of the core. A distributed loss, which can be enhanced by bending, is produced at the Raman frequency which effectively raises the threshold at which Raman scattering occurs in the fiber and therefore results in a frequency-selective fiber. In another embodiment, an absorbing layer is placed around the core region. The absorbing layer is chosen to have a sharp absorption edge so that it absorbs highly at the Raman-shifted wavelength, but minimally at the desired lasing wavelength.
    Type: Grant
    Filed: April 5, 1999
    Date of Patent: September 12, 2000
    Assignee: SDL, Inc.
    Inventors: Stephen G. Grubb, Raymond Zanoni, Robert G. Waarts, Jean-Luc Archambault
  • Patent number: 6081369
    Abstract: An optical amplifier system includes a fiber amplifier doped with rare earth dopant provided in its fiber core. A plurality of fiber lasers have their light outputs optically coupled together for launching into the fiber amplifier for optically pumping the amplifier. Each of the fiber lasers have a rare earth dopant provided in its fiber core for stimulated lasing emission with the rare earth dopant of the fiber amplifier being different from the rear earth dopant of the fiber lasers. A reflector may be provided in each of the coupling fibers for reflecting a portion of the respective light outputs back into the fiber lasers to control their wavelength of operation, the wavelength of operation of the reflectors chosen to be within a high absorption region of the absorption band of the fiber amplifier. Where the pump source is a semiconductor laser source, the source may include a flared gain section to increase the output intensity of the light output of the source.
    Type: Grant
    Filed: August 2, 1999
    Date of Patent: June 27, 2000
    Assignee: SDL., Inc.
    Inventors: Robert G. Waarts, Steven Sanders, David F. Welch
  • Patent number: 6049415
    Abstract: A number of variations are provided of a device that provides an amplified single polarization optical signal. Each of these relies on the use of a non-polarization maintaining gain medium through which the signal is directed, and a polarization shifter and reflector that direct the signal back through the same gain medium with a shifted polarization state. An input polarization beamsplitter directs the returning optical signal away to an output, based on its shifted polarization state. The embodiments of the invention include the use of double-clad fiber. Multiple stages may be used to provide specific amplification parameters. In one embodiment, both amplification stages reside in the same polarization shifting optical path. A polarization maintaining amplifier of this type may be used as part of a master oscillator-power amplifier, in which polarization maintaining fiber is used as part of the source laser.
    Type: Grant
    Filed: December 8, 1997
    Date of Patent: April 11, 2000
    Assignee: SDL, Inc.
    Inventors: Stephen G. Grubb, Paul Freeman, Stuart MacCormack, Robert G. Waarts