Patents by Inventor Tirmula R. Ranganath

Tirmula R. Ranganath 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).

  • Long-Wavelength VCSEL using buried bragg reflectors
    Patent number: 6252896
    Abstract: An optically pumped vertical-cavity surface-emitting laser (VCSEL) device and a method of fabricating the device utilize two separate substrates that perform a filtering operation to selectively transmit only light having a long peak wavelength that is generated by the device. The optically pumped VCSEL device is a self-pumped device that can generate the pump light to drive the device to emit output laser light having a long peak wavelength. The optically pumped VCSEL device includes a short-wavelength VCSEL formed on one of the two substrates and a long-wavelength VCSEL formed on the other substrate. The short-wavelength VCSEL is a current-driven VCSEL that generates short-wavelength light to drive (i.e., optically pump) the long-wavelength VCSEL. The short-wavelength VCSEL and the long-wavelength VCSEL are bonded together such that the two substrates are separated by the two VCSELs.
    Type: Grant
    Filed: March 5, 1999
    Date of Patent: June 26, 2001
    Assignee: Agilent Technologies, Inc.
    Inventors: Michael R. T. Tan, Dubravko I. Babic, Scott W. Corzine, Tirmula R. Ranganath, Shih-Yuan Wang, Wayne Bi