Patents by Inventor Tirumala Ranganath

Tirumala 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).

  • Publication number: 20070176728
    Abstract: In accordance with the invention, a tiled periodic metal film sensor can be used to measure refractive index changes of a thin layer of liquid to determine changes in the liquid composition. The tiled periodic metal film sensor senses reflected light as a function of wavelength and infers a change in the refractive index of the fluid.
    Type: Application
    Filed: January 31, 2006
    Publication date: August 2, 2007
    Inventors: Tirumala Ranganath, Mihail Sigalas
  • Publication number: 20070099238
    Abstract: Fluorescent dyes or quantum dots may be embedded in a dielectric volume of appropriate dimensions where typically half the surface of the dielectric volume is covered by a metal coating allow for increased absorption and emission efficiencies. Alternatively, fluorescent dyes or quantum dots may be attached to metal coated dielectric shapes using the appropriate chemistries.
    Type: Application
    Filed: October 31, 2005
    Publication date: May 3, 2007
    Inventors: Mihail Sigalas, Tirumala Ranganath
  • Publication number: 20070052535
    Abstract: An object locator system in accordance with the invention includes an activator unit and an object incorporating an embedded signal generator to generate a signal that provides location information of the object. A power switch of the object is settable to a first position where a power source of the object is coupled to an electronic load, and to a second position where the power source is coupled to the embedded signal generator.
    Type: Application
    Filed: September 2, 2005
    Publication date: March 8, 2007
    Inventor: Tirumala Ranganath
  • Publication number: 20070052814
    Abstract: Method and apparatus for white-balancing an image of an object. Light reflected from the object illuminated with light having known spectral characteristics is collected, and the spectral reflectivity characteristics of the object is determined from the collected light. Light reflected from the object illuminated with light having unknown spectral characteristics is collected to form an image of the object, and the formed image is white-balanced in accordance with the determined spectral reflectivity characteristics of the object.
    Type: Application
    Filed: September 7, 2005
    Publication date: March 8, 2007
    Inventor: Tirumala Ranganath
  • Publication number: 20070037365
    Abstract: During the growth of semiconductor nanowires on a substrate, different respective vapor-liquid-solid reactions that respectively form target segments and sacrificial segments of the semiconductor nanowires at growth locations defined by catalyst particles are supported. The sacrificial segments of the semiconductor nanowires are selectively removed to form semiconductor nanostructures corresponding to the target segments of the semiconductor nanowires.
    Type: Application
    Filed: August 15, 2005
    Publication date: February 15, 2007
    Inventors: Tirumala Ranganath, Sungsoo Yi, William McAllister
  • Publication number: 20060062537
    Abstract: Undoped layers are introduced in the passive waveguide section of a butt-joined passive waveguide connected to an active structure. This reduces the parasitic capacitance of the structure.
    Type: Application
    Filed: September 17, 2004
    Publication date: March 23, 2006
    Inventors: Tirumala Ranganath, Jintian Zhu
  • Publication number: 20060051103
    Abstract: Multi-channel Fabry-Perot laser transmitters and methods of generating multiple modulated optical signals are described. In one aspect, an optical transmitter includes a Fabry-Perot (FP) laser, an optical isolator, an optical splitter, and multiple electroabsorption modulators (EAMs). The FP laser is operable to generate multimode laser light. The optical isolator is arranged to transmit the multimode laser light. The optical splitter has more than one optical output and an optical input that is arranged to receive the multimode laser light transmitted by the optical isolator. Each of the EAMs is operable to modulate a respective laser light output from a respective optical output of the optical splitter. In another aspect, multimode laser light is generated. The multimode laser light is directionally isolated. The directionally-isolated multimode laser light is divided into more than one divided laser light output.
    Type: Application
    Filed: September 8, 2004
    Publication date: March 9, 2006
    Inventor: Tirumala Ranganath
  • Publication number: 20060024000
    Abstract: A concentration of particles or a single particle may be detected using a conducting cavity sensor. The conducting cavity sensor includes a two dimensional periodic lattice of conducting rods surrounded by a dielectric medium with a defect in the periodic lattice serving as the sensing volume.
    Type: Application
    Filed: September 26, 2005
    Publication date: February 2, 2006
    Inventors: Mihail Sigalas, Tirumala Ranganath
  • Publication number: 20050276615
    Abstract: Electroabsorption-modulated Fabry-Perot lasers and methods of making the same are described. In one aspect, a light source includes a Fabry-Perot (FP) laser that is operable to generate multimode laser light, an electroabsorption modulator (EAM) that is configured to selectively absorb and transmit laser light traveling therethrough, and an optical isolator. The optical isolator is on an optical path between the FP laser and the EAM. The optical isolator is configured to transmit laser light traveling along the optical path from the FP laser to the EAM.
    Type: Application
    Filed: June 15, 2004
    Publication date: December 15, 2005
    Inventor: Tirumala Ranganath
  • Publication number: 20050274941
    Abstract: Semiconductor quantum well devices and methods of making the same are described. In one aspect, a device includes a quantum well structure that includes semiconductor layers defining interleaved heavy-hole and light-hole valance band quantum wells. Each of the quantum wells includes a quantum well layer interposed between barrier layers. One of the semiconductor layers that functions as a barrier layer of one of the light-hole quantum wells also functions as the quantum well layer of one of the heavy-hole quantum wells. Another of the semiconductor layers that functions as a barrier layer of one of the heavy-hole quantum wells also functions as the quantum well layer of one of the light-hole quantum wells.
    Type: Application
    Filed: June 14, 2004
    Publication date: December 15, 2005
    Inventor: Tirumala Ranganath
  • Publication number: 20050258430
    Abstract: Electro-absorption modulators and methods of making the same are described. In one aspect, an electroabsorption modulator includes first and second electrodes, first and second cladding regions, an active region, and a tunnel junction structure. The first and second cladding regions are between the first and second electrodes. The active region is between the first and second cladding regions and includes a light absorption region. The tunnel junction structure is between the active region and one of the first and second cladding regions.
    Type: Application
    Filed: May 19, 2004
    Publication date: November 24, 2005
    Inventor: Tirumala Ranganath