Patents by Inventor Francis Pascal Romstad

Francis Pascal Romstad 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).

  • Method for fabricating a photonic crystal or photonic bandgap vertical-cavity surface-emitting laser
    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
  • Single-mode photonic-crystal VCSELs
    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
  • METHOD FOR FABRICATING A PHOTONIC CRYSTAL OR PHOTONIC BANDGAP VERTICAL-CAVITY SURFACE-EMITTING LASER
    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
  • Single-Mode Photonic-Crystal Vcsels
    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