Patents by Inventor Manuela Buda

Manuela Buda 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: 7251381
    Abstract: A single-mode optical device, including a first region, and a second region laterally disposed about the first region, and including an absorbing layer and an isolation layer between the absorbing layer and the first region, wherein the thickness of the isolation layer is selected to control optical loss from the first region to the absorbing layer in the second region and thereby to attenuate one or more high order lateral optical modes of the device. The one or more high order lateral optical modes are attenuated relative to the fundamental lateral mode to provide the device with a high kink power. The device can be a 980 nm ridge diode laser where the thickness of an oxide insulating layer around the ridge is selected to control optical losses into a gold contact layer and thereby attenuate the first order lateral mode, providing the laser with a kink power of at least about 250 mW.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: July 31, 2007
    Assignee: The Australian National University
    Inventors: Manuela Buda, Hark Hoe Tan, Lan Fu, Lalita Josyula, Michael Francis Aggett, Chennupati Jagadish
  • Patent number: 6993053
    Abstract: A diode laser having a plurality of layers including a thin (e.g., about 0.3 ?m or less) p-type cladding layer, the plurality of layers having a substantially asymmetric refractive index profile with respect to the layer growth direction to produce an optical field distribution with a larger fraction of the distribution in n-type layers than in p-type layers of the laser. The layers can be configured to produce a ridge diode laser having an internal loss less than about 3 cm?1, and able to generate an approximately 980 nm laser beam with a transverse divergence of about 28° or less, and a spot size of about 0.8 ?m or more.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: January 31, 2006
    Assignee: The Australian National University
    Inventors: Manuela Buda, Jillian Alice Hay, Hark Hoe Tan, Chennupati Jagadish
  • Patent number: 6882670
    Abstract: A diode laser formed by a plurality of layers including n-type layers and p-type layers, the plurality of layers having a substantially asymmetric refractive index profile with respect to the layer growth direction so as to generate an optical field distribution with a larger fraction in n-type layers than in p-type layers, and configured to generate a beam with a divergence of less than about 28° in the growth direction. The layers include an active layer for generating the optical field, a trap layer for attracting the optical field, and a separation layer between the active layer and the trap layer for repelling the optical field. The laser can be configured to have an internal loss of about 1.2 cm?1 or less, and to generate a laser beam with a spot size of at least about 1.1 ?m and a divergence of approximately 13° in the growth direction. If the length of the laser is at least about 1 mm, the threshold current density of the laser can be less than about 400 A cm?2.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: April 19, 2005
    Assignee: The Australian National University
    Inventors: Manuela Buda, Hark Hoe Tan, Michael Francis Aggett, Chennupati Jagadish
  • Publication number: 20040028104
    Abstract: A diode laser having a plurality of layers including a thin (e.g., about 0.3 &mgr;m or less) p-type cladding layer, the plurality of layers having a substantially asymmetric refractive index profile with respect to the layer growth direction to produce an optical field distribution with a larger fraction of the distribution in n-type layers than in p-type layers of the laser. The layers can be configured to produce a ridge diode laser having an internal loss less than about 3 cm−1, and able to generate an approximately 980 nm laser beam with a transverse divergence of about 28° or less, and a spot size of about 0.8 &mgr;m or more.
    Type: Application
    Filed: April 3, 2003
    Publication date: February 12, 2004
    Inventors: Manuela Buda, Jillian Alice Hay, Hark Hoe Tan, Chennupati Jagadish
  • Publication number: 20040017836
    Abstract: A single-mode optical device, including a first region, and a second region laterally disposed about the first region, and including an absorbing layer and an isolation layer between the absorbing layer and the first region, wherein the thickness of the isolation layer is selected to control optical loss from the first region to the absorbing layer in the second region and thereby to attenuate one or more high order lateral optical modes of the device. The one or more high order lateral optical modes are attenuated relative to the fundamental lateral mode to provide the device with a high kink power. The device can be a 980 nm ridge diode laser where the thickness of an oxide insulating layer around the ridge is selected to control optical losses into a gold contact layer and thereby attenuate the first order lateral mode, providing the laser with a kink power of at least about 250 mW.
    Type: Application
    Filed: April 3, 2003
    Publication date: January 29, 2004
    Inventors: Manuela Buda, Hark Hoe Tan, Lan Fu, Lalita Josyula, Michael Francis Aggett, Chennupati Jagadish
  • Publication number: 20040013147
    Abstract: A diode laser formed by a plurality of layers including n-type layers and p-type layers, the plurality of layers having a substantially asymmetric refractive index profile with respect to the layer growth direction so as to generate an optical field distribution with a larger fraction in n-type layers than in p-type layers, and configured to generate a beam with a divergence of less than about 28° in the growth direction. The layers include an active layer for generating the optical field, a trap layer for attracting the optical field, and a separation layer between the active layer and the trap layer for repelling the optical field. The laser can be configured to have an internal loss of about 1.2 cm−1 or less, and to generate a laser beam with a spot size of at least about 1.1 &mgr;m and a divergence of approximately 13° in the growth direction. If the length of the laser is at least about 1 mm, the threshold current density of the laser can be less than about 400 A cm−2.
    Type: Application
    Filed: April 3, 2003
    Publication date: January 22, 2004
    Inventors: Manuela Buda, Hark Hoe Tan, Michael Francis Aggett, Chennupati Jagadish
  • Patent number: 6522677
    Abstract: The high power laser diode comprise an active region and a trapping region separated by a passive region, all situated between a p-type confinement region and an n type confinement region such that the radiation field is attracted toward and spread into the trapping region assuring a reduced value for the confinement factor into the active region.
    Type: Grant
    Filed: November 30, 1999
    Date of Patent: February 18, 2003
    Inventors: Iulian Basarab Petrescu-Prahova, Manuela Buda, Aurel Mihai Vlaicu