Patents by Inventor Gregory J. Letal

Gregory J. Letal 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: 6797533
    Abstract: A quantum well structure having an indium gallium arsenide phosphide (InGaAsP) quantum well active region has a low temperature grown indium phosphide (LT-InP) cap layer grown on it. Defects in the cap layer are intermixed into the quantum well active region by rapid thermal annealing to produce a blue shift in the active region. The blue shift increases as the growth temperature of the LT-InP cap layer decreases or as the phosphine flow rate during production of the LT-InP layer increases.
    Type: Grant
    Filed: October 4, 2002
    Date of Patent: September 28, 2004
    Assignee: McMaster University
    Inventors: David A. Thompson, Bradley J. Robinson, Gregory J. Letal, Alex S. W. Lee, Brooke Gordon
  • Patent number: 6611007
    Abstract: A novel quantum well intermixing method for regionally modifying the bandgap properties of InGaAsP quantum well structures is disclosed. The method induces bandgap wavelength blue shifting and deep states for reducing carrier lifetime within InGaAsP quantum well structures. The novel quantum well intermixing technique is applied to the modulator section of an integrated DFB laser/electro-absorption modulator, wherein the modulator exhibits fast switching times with efficient optical coupling between the DFB laser and modulator region.
    Type: Grant
    Filed: May 9, 2002
    Date of Patent: August 26, 2003
    Assignee: Fiber Optic Systems Technology, Inc.
    Inventors: David A. Thompson, Brad J. Robinson, Gregory J. Letal, Alex S. W. Lee
  • Publication number: 20030071265
    Abstract: A quantum well structure having an indium gallium arsenide phosphide (InGaAsP) quantum well active region has a low temperature grown indium phosphide (LT-InP) cap layer grown on it. Defects in the cap layer are intermixed into the quantum well active region by rapid thermal annealing to produce a blue shift in the active region. The blue shift increases as the growth temperature of the LT-InP cap layer decreases or as the phosphine flow rate during production of the LT-InP layer increases.
    Type: Application
    Filed: October 4, 2002
    Publication date: April 17, 2003
    Applicant: FOX TEK
    Inventors: David A. Thompson, Bradley J. Robinson, Gregory J. Letal, Alex S.W. Lee, Brooke Gordon
  • Publication number: 20020127752
    Abstract: A novel quantum well intermixing method for regionally modifying the bandgap properties of InGaAsP quantum well structures is disclosed. The method induces bandgap wavelength blue shifting and deep states for reducing carrier lifetime within InGaAsP quantum well structures. The novel quantum well intermixing technique is applied to the modulator section of an integrated DFB laser/electro-absorption modulator, wherein the modulator exhibits fast switching times with efficient optical coupling between the DFB laser and modulator region.
    Type: Application
    Filed: May 9, 2002
    Publication date: September 12, 2002
    Inventors: David A. Thompson, Brad J. Robinson, Gregory J. Letal, Alex S.W. Lee
  • Publication number: 20020030185
    Abstract: A novel quantum well intermixing method for regionally modifying the bandgap properties of InGaAsP quantum well structures is disclosed. The method induces bandgap wavelength blue shifting and deep states for reducing carrier lifetime within InGaAsP quantum well structures. The novel quantum well intermixing technique is applied to the modulator section of an integrated DFB laser/electro-absorption modulator, wherein the modulator exhibits fast switching times with efficient optical coupling between the DFB laser and modulator region.
    Type: Application
    Filed: April 12, 2001
    Publication date: March 14, 2002
    Inventors: David A. Thompson, Brad J. Robinson, Gregory J. Letal, Alex S.W. Lee