Patents by Inventor Dan Birkedal

Dan Birkedal 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: 7883914
    Abstract: The invention relates to fabrication of VCSELs. It provides a method for fabricating a VCSEL that contains a micro/nano-structured mode selective lateral layer, where the micro/nano-structured layer is obtained by well controlled local etching. The invention enables control of the micro/nano-structured layer thickness with very high precision. In particular, the invention relates to a method for fabricating a VCSEL with a micro/nano-structured mode selective layer for controlling the VCSELs transverse electromagnetic modes.
    Type: Grant
    Filed: May 27, 2007
    Date of Patent: February 8, 2011
    Assignee: Alight Technologies A/S
    Inventors: Dan Birkedal, Svend Bischoff, Michael Juhl, Magnus Hald Madsen, Francis Pascal Romstad
  • Patent number: 7693203
    Abstract: This specification discloses a VCSEL (Vertical-Cavity Surface-Emitting Laser) device with single-mode output and optionally single polarization output. This device is given by lateral mode confinement by the PBG (Photonic Band-Gap) effect by shallow etching in a partial VCSEL top mirror. The PBG area encircles a MS-region (Mode-Shaping region), which is characterized by large longitudinal mode losses. The MS-region encircles the LA-region (Light Aperture region), which is characterised by low longitudinal mode losses. The MS-region does not contribute to the lateral mode-confinement to the LA-aperture, and the lateral modes confined by the PBG area. The VCSEL is thus optimized for single fundamental mode operation.
    Type: Grant
    Filed: November 29, 2005
    Date of Patent: April 6, 2010
    Assignee: Alight Photonics APS
    Inventors: Dan Birkedal, Svend Bischoff, Michael Juhl, Magnus Hald Madsen, Francis Pascal Romstad
  • Publication number: 20090203158
    Abstract: The invention relates to fabrication of VCSELs. It provides a method for fabricating a VCSEL that contains a micro/nano-structured mode selective lateral layer, where the micro/nano-structured layer is obtained by well controlled local etching. The invention enables control of the micro/nano-structured layer thickness with very high precision. In particular, the invention relates to a method for fabricating a VCSEL with a micro/nano-structured mode selective layer for controlling the VCSELs transverse electromagnetic modes.
    Type: Application
    Filed: May 27, 2007
    Publication date: August 13, 2009
    Inventors: Dan Birkedal, Svend Bischoff, Michael Juhl, Magnus Hald Madsen, Francis Pascal Romstad
  • Publication number: 20080219307
    Abstract: This specification discloses a VCSEL (Vertical-Cavity Surface-Emitting Laser) device with single-mode output and optionally single polarization output. This device is given by lateral mode confinement by the PBG (Photonic Band-Gap) effect by shallow etching in a partial VCSEL top mirror. The PBG area encircles a MS-region (Mode-Shaping region), which is characterized by large longitudinal mode losses. The MS-region encircles the LA-region (Light Aperture region), which is characterised by low longitudinal mode losses. The MS-region does not contribute to the lateral mode-confinement to the LA-aperture, and the lateral modes confined by the PBG area. The VCSEL is thus optimized for single fundamental mode operation.
    Type: Application
    Filed: November 29, 2005
    Publication date: September 11, 2008
    Inventors: Dan Birkedal, Svend Bischoff, Michael Juhl, Magnus Hald Madsen, Francis Pascal Romstad
  • Patent number: 6683898
    Abstract: A vertical cavity surface emitting laser (VCSEL) having a photonic band gap (PBG) region formed within or adjacent to a first and/or a second mirror, or within a spacer layer positioned between a gain region and at least one of the mirrors. The PBG region has a predetermined periodicity which substantially prevents the generated light from propagating the region, and defines a light aperture without the periodicity so as to allow the generated light to propagate through the aperture. The PBG region does not extend through the gain region, thereby allowing the full gain region to be used. Controls the efficiency of laser action by suppressing or preventing laser action in certain modes without losses, rather the modes are made forbidden. Energy from the forbidden modes is eventually coupled back to the allowed mode(s). Provides a separation of the confinement of the gain region and the mode control without introducing energy losses.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: January 27, 2004
    Assignee: Alight Technologies A/S
    Inventors: John Erland Østergaard, Dan Birkedal
  • Publication number: 20020163947
    Abstract: A vertical cavity surface emitting laser (VCSEL) having a photonic band gap (PBG) region formed within or adjacent to a first and/or a second mirror, or within a spacer layer positioned between a gain region and at least one of the mirrors. The PBG region has a predetermined periodicity which substantially prevents the generated light from propagating the region, and defines a light aperture without the periodicity so as to allow the generated light to propagate through the aperture. The PBG region does not extend through the gain region, thereby allowing the full gain region to be used. Controls the efficiency of laser action by suppressing or preventing laser action in certain modes without losses, rather the modes are made forbidden. Energy from the forbidden modes is eventually coupled back to the allowed mode(s).
    Type: Application
    Filed: March 8, 2002
    Publication date: November 7, 2002
    Inventors: John Erland Ostergaard, Dan Birkedal