Patents by Inventor Stig Nissen Knudsen

Stig Nissen Knudsen 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: 6865327
    Abstract: Applicants have discovered the existence of loss peaks in optical fiber transmission systems using wavelengths in the E-band and the L-band. Specifically, they have discovered the existence of narrow loss peaks at 1440 nm, 1583 nm and 1614 nm. Because the peaks are relatively narrow, they cannot be easily removed by conventional gain equalizers in long haul transmission systems, and although the peaks are relatively small, they can nonetheless cause transmission channels to drop out in amplified DWDM transmission systems. Applicants have further discovered that these loss peaks are due to carbon contamination of the transmission fiber. Thus optical fibers should be fabricated essentially free of carbon contamination. This means eliminating carbon-containing reagents in preform and tube-making processes.
    Type: Grant
    Filed: September 19, 2002
    Date of Patent: March 8, 2005
    Assignee: Fitel USA Corp.
    Inventors: Robert M. Atkins, Alice W. Liu, Poul Kristensen, Morten Østergaard Pedersen, Stig Nissen Knudsen, Jan Levin Nielsen, Jake Bromage, Kai H. Chang
  • Patent number: 6707976
    Abstract: An inverse dispersion fiber is provided that has a relatively low fiber loss, a relatively low fiber splice loss and a relatively large effective mode-field area. The inverse dispersion fiber includes a doped core region with an index of refraction n1, a cladding region with an index of refraction n2, and a trench region, a first barrier region and a second barrier region with indices of refraction n3, n4, and n5, respectively, formed between the doped core region and the cladding region. The various regions of the inverse dispersion fiber are manufactured in such a way that the refractive index value ranges are, for example, approximately 0.709%<(n1−n2)/n2<1.0%, approximately −0.358%<(n3−n2)/n2<−0.293%, approximately 0.194%<(n4−n2)/n2<0.237%, and approximately −0.045%<(n5−n2)/n2<−0.037%.
    Type: Grant
    Filed: September 4, 2002
    Date of Patent: March 16, 2004
    Assignee: Fitel USA Corporation
    Inventors: Lars Gruner-Nielsen, Stig Nissen Knudsen, Morten Ostergaard Pedersen
  • Publication number: 20040042748
    Abstract: An inverse dispersion fiber is provided that has a relatively low fiber loss, a relatively low fiber splice loss and a relatively large effective mode-field area. The inverse dispersion fiber includes a doped core region with an index of refraction n1, a cladding region with an index of refraction n2, and a trench region, a first barrier region and a second barrier region with indices of refraction n3, n4, and n5, respectively, formed between the doped core region and the cladding region. The various regions of the inverse dispersion fiber are manufactured in such a way that the refractive index value ranges are, for example, approximately 0.709%<(n1−n2)/n2<1.0%, approximately −0.358%<(n3−n2)/n2<−0.293%, approximately 0.194%<(n4−n2)/n2<0.237%, and approximately −0.045%<(n5−n2)/n2<−0.037%.
    Type: Application
    Filed: September 4, 2002
    Publication date: March 4, 2004
    Inventors: Lars Gruner-Nielsen, Stig Nissen Knudsen, Morten Ostergaard Pedersen
  • Publication number: 20040042746
    Abstract: Applicants have discovered the existence of loss peaks in optical fiber transmission systems using wavelengths in the E-band and the L-band. Specifically, they have discovered the existence of narrow loss peaks at 1440 nm, 1583 nm and 1614 nm. Because the peaks are relatively narrow, they cannot be easily removed by conventional gain equalizers in long haul transmission systems, and although the peaks are relatively small, they can nonetheless cause transmission channels to drop out in amplified DWDM transmission systems. Applicants have further discovered that these loss peaks are due to carbon contamination of the transmission fiber. Thus optical fibers should be fabricated essentially free of carbon contamination. This means eliminating carbon-containing reagents in preform and tube-making processes.
    Type: Application
    Filed: September 19, 2002
    Publication date: March 4, 2004
    Inventors: Robert M. Atkins, Alice W. Liu, Poul Kristensen, Morten Ostergaard Pedersen, Stig Nissen Knudsen, Jan Levin Nielsen, Jake Bromage, Kai H. Chang
  • Patent number: 6633715
    Abstract: Embodiments of the invention include an optical communications system with optical fiber cable, coupled between optical transmission and receiving devices, having positive dispersion fiber and corresponding inverse dispersion fiber. The inverse dispersion fiber includes a doped core region with an index of refraction n1, a cladding region with an index of refraction n2, and a trench region, a first barrier region and a second barrier region with indices of refraction n3, n4, and n5, respectively, formed between the doped core region and the cladding region. The various regions of the inverse dispersion fiber are manufactured in such a way that the refractive index value ranges are, e.g., 0.745%<(n1−n2)/n2<0.759%,−0.403%<(n3−n2)/n2<−0.394%, 0.152%<(n4−n2)/n2<0.166%, and −0.083%<(n5−n2)/n2<−0.041%.
    Type: Grant
    Filed: December 6, 2001
    Date of Patent: October 14, 2003
    Assignee: Fitel USA Corp.
    Inventors: Stig Nissen Knudsen, Morten Ostergaard Pedersen
  • Patent number: 6603914
    Abstract: A dispersion compensating fiber is described having a core and cladding as well as methods for making such fiber. The cladding has a first cladding region surrounding the core, a second cladding region surrounding the first cladding region, and a third cladding region surrounding the second cladding region. The core, and the first, second, and third cladding regions are doped to create a refraction index profile characteristic of dispersion compensating fiber. The core is doped with germanium, the first cladding region is doped with fluorine, and the second cladding region is doped with germanium and fluorine. A portion of the cladding is doped with phosphorus, thereby resulting in splice loss reduction.
    Type: Grant
    Filed: February 7, 2001
    Date of Patent: August 5, 2003
    Assignee: Fitel USA Corp.
    Inventors: Bent Edvold, Lars Gruner-Nielsen, Stig Nissen Knudsen, Torben Erik Veng
  • Publication number: 20030113084
    Abstract: Embodiments of the invention include an optical communications system with optical fiber cable, coupled between optical transmission and receiving devices, having positive dispersion fiber and corresponding inverse dispersion fiber. The inverse dispersion fiber includes a doped core region with an index of refraction n1, a cladding region with an index of refraction n2, and a trench region, a first barrier region and a second barrier region with indices of refraction n3, n4, and n5, respectively, formed between the doped core region and the cladding region. The various regions of the inverse dispersion fiber are manufactured in such a way that the refractive index value ranges are, e.g., 0.745%<(n1−n2)/n2<0.759%, −0.403%<(n3−n2)/n2<−0.394%, 0.152%<(n4−n2)/2<0.166%, and −0.083%<(n5−n2)/n2<−0.041%.
    Type: Application
    Filed: December 6, 2001
    Publication date: June 19, 2003
    Inventors: Stig Nissen Knudsen, Morten Ostergaard Pedersen
  • Publication number: 20020159735
    Abstract: A dispersion compensating fiber is described having a core and cladding. The cladding has a first cladding region surrounding the core, a second cladding region surrounding the first cladding layer, and a third cladding region surrounding the second cladding layer. The core, and the first, second, and third cladding regions are doped to create a refraction index profile characteristic of dispersion compensating fiber. A portion of the cladding is doped with phosphorus, thereby resulting in splice loss reduction.
    Type: Application
    Filed: February 7, 2001
    Publication date: October 31, 2002
    Inventors: Bent Edvold, Lars Gruner-Nielsen, Stig Nissen Knudsen, Torben Erik Veng