Patents by Inventor Renganathan Ashokan

Renganathan Ashokan 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: 9031195
    Abstract: An imaging detector includes a scintillator having a scintillator pixel that is configured to emit light. The detector also includes a photosensor that defines a photosensor pixel that is configured to absorb light emitted by the scintillator pixel. A lens is positioned between the scintillator pixel and the photosensor pixel for directing light emitted from the scintillator to the photosensor pixel. The lens is configured to converge light emitted from the scintillator pixel toward the photosensor pixel.
    Type: Grant
    Filed: May 20, 2011
    Date of Patent: May 12, 2015
    Assignee: General Electric Company
    Inventors: Renganathan Ashokan, Reinaldo Gonzalez
  • Publication number: 20120294416
    Abstract: An imaging detector includes a scintillator having a scintillator pixel that is configured to emit light. The detector also includes a photosensor that defines a photosensor pixel that is configured to absorb light emitted by the scintillator pixel. A lens is positioned between the scintillator pixel and the photosensor pixel for directing light emitted from the scintillator to the photosensor pixel. The lens is configured to converge light emitted from the scintillator pixel toward the photosensor pixel.
    Type: Application
    Filed: May 20, 2011
    Publication date: November 22, 2012
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Renganathan Ashokan, Reinaldo Gonzalez
  • Patent number: 6657194
    Abstract: At a face of a silicon semiconductor substrate tilted about one degree from a [100] orientation, a readout integrated circuit (ROIC) is implemented, specially designed and fabricated for direct epitaxial growth. Layers of II-VI semiconductor material, preferably including layers of HgCdTe of different bandgaps, are successively and monolithically grown on the face by molecular beam epitaxy (MBE) within a window masking the face and then patterned and wet-etched to create mesas of two-color detector elements in an array. Preferably a beginning buffer layer of CdTe is grown to minimize crystalline mismatch between the Si and the HgCdTe. Sloped sidewalls of the mesas ensure good step coverage of the conductive interconnects from the detector elements to the ROIC.
    Type: Grant
    Filed: April 13, 2001
    Date of Patent: December 2, 2003
    Assignee: EPIR Technologies, Inc.
    Inventors: Renganathan Ashokan, Paul Boieriu, Yuanping Chen, Jean-Pierre Faurie, Sivalingam Sivananthan
  • Publication number: 20030160172
    Abstract: Multispectral infrared detectors are needed for advanced imaging systems with capabilities to discriminate actual targets against decoys. Simultaneous detection of the infrared radiation emitted by the target in more than one wavelength range has significant advantages for this purpose. In the current invention, a technology for producing a plurality of multi-color infrared sensing elements in a monolithic array format is provided. Each element has a multi-layer structure of mercury cadmium telluride (HgCdTe), a group II-VI semiconductor. The unit cell of the integrated detector consists of two co-located detectors, each sensitive to a different infrared wavelength. The prior art to produce such infrared device arrays is ‘hybrid technology’, meaning the infrared sensing elements and the read-out electronics are fabricated on two different materials-silicon and HgCdTe and joined together by indium pillars/bumps.
    Type: Application
    Filed: April 13, 2001
    Publication date: August 28, 2003
    Applicant: EPIR LTD.
    Inventors: Renganathan Ashokan, Paul Boieriu, Yuanping Chen, Jean-Pierre Faurie, Sivalingam Sivananthan
  • Publication number: 20030102432
    Abstract: An infrared sensing device including a multi-layer II-VI semiconductor material grown by molecular beam epitaxy on a readout circuit fabricated on silicon substrate having a orientation one degree tilted from the (100) direction is provided in this invention. A method to grow single crystalline mercury cadmium telluride multi-layer structure on custom-designed readout circuit (ROIC) is provided. Due to the height difference of more than 15 micron between the two planes containing the detector output gates and the ROIC signal input gates, a mesa with at least one sloped side is fabricated and the interconnecting metal electrodes running on them to connect the detector output to ROIC input. Planar photovoltaic junctions are fabricated selectively on the II-VI mesa structure formed on ROIC. At least one infrared detecting cell being formed in the mesa, with a conductor interconnect layer connecting the detection cell to the readout integrated circuit.
    Type: Application
    Filed: April 12, 2001
    Publication date: June 5, 2003
    Applicant: EPIR LTD.
    Inventors: Paul Boieriu, Renganathan Ashokan, Yuanping Chen, Jean-Pierre Faurie, Sivalingam Sivananthan