Patents by Inventor Craig D. Liddle

Craig D. Liddle 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).

  • Birefringence compensated integrated optical switching or modulation device
    Patent number: 6760499
    Abstract: A planar waveguide Mach-Zehnder interferometer (MZ) has improved performance as a variable optical attenuator as well as a thermo-optic switch (TOS) with reduced polarization dependent loss (PDL) in high attenuation states. The PDL was reduced by correcting for the increased birefringence that occurs on heating one waveguide arm by making the two waveguides inherently asymmetric, such that when one of the waveguides is heated, the differential birefringence of the two arms becomes zero. This asymmetry can be realized simply by changing the width of one of the waveguides. The modified device allows for very small PDL in the high attenuation state of a VOA and for theoretically perfect contrast in a TOS in the off state, with only a small penalty in PDL of the on state.
    Type: Grant
    Filed: July 8, 2002
    Date of Patent: July 6, 2004
    Assignee: JDS Uniphase Corporation
    Inventors: Bardia Pezeshki, Mark Missey, Anca L. Sala, Craig D. Liddle, Barthelemy Fondeur
  • Birefringence compensated integrated optical switching or modulation device
    Publication number: 20030026518
    Abstract: A planar waveguide Mach-Zehnder interferometer (MZ) has improved performance as a variable optical attenuator as well as a thermo-optic switch (TOS) with reduced polarization dependent loss (PDL) in high attenuation states. The PDL was reduced by correcting for the increased birefringence that occurs on heating one waveguide arm by making the two waveguides inherently asymmetric, such that when one of the waveguides is heated, the differential birefringence of the two arms becomes zero. This asymmetry can be realized simply by changing the width of one of the waveguides. The modified device allows for very small PDL in the high attenuation state of a VOA and for theoretically perfect contrast in a TOS in the off state, with only a small penalty in PDL of the on state.
    Type: Application
    Filed: July 8, 2002
    Publication date: February 6, 2003
    Applicant: JDS Uniphase Corporation
    Inventors: Bardia Pezeshki, Mark Missey, Anca L. Sala, Craig D. Liddle, Barthelemy Fondeur