Patents by Inventor Chellappan Narayanan

Chellappan Narayanan 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: 20200220319
    Abstract: In an example, a mode-locked laser includes a resonator cavity having a saturable absorber, a hollow core fiber coupled to the saturable absorber, and an optical amplifier optically coupled between the hollow core fiber and an output coupler. The mode-locked laser further includes a first pump laser and a wavelength division multiplexer coupled to the first pump laser. The wavelength division multiplexer is configured to couple light from the first pump laser into the resonator cavity to pump the optical amplifier. The mode-locked laser is configured to generate a pulse waveform at a repetition rate of approximately 100 MHz to 200 MHz.
    Type: Application
    Filed: January 9, 2019
    Publication date: July 9, 2020
    Applicant: Honeywell International Inc.
    Inventors: Chellappan Narayanan, Jeffrey Earl Lewis, Sorin Mosor, Tiequn Qiu
  • Publication number: 20200073895
    Abstract: A device may receive a query from a user device, and may process the query using a machine learning model to determine categories related to the query. The device may send a message, instructing a user to select a category, to the user device to cause the user device to display the message. The device may receive, from the user device, a selection related to the categories, and may call, based on the selection, a module to cause the module to process the query. The device may receive from the module a response to the query, and may send the response to the user device, to cause the user device to display the response. The device may send the query, the selection, and the response to one or more servers for storage, and may retrain the machine learning model based on information stored by the one or more servers.
    Type: Application
    Filed: August 12, 2019
    Publication date: March 5, 2020
    Inventors: Ashok VIRA, Raghavan IYER, Sangita AGARWAL, N.R. SRIKANTH, Chellappan MURUGAPPAN, Swetha KOMMARAJU, Sankara NARAYANAN
  • Patent number: 10451421
    Abstract: An optical resonator is provided. The optical resonator comprises: an optical resonator coil comprising a first port and a second port; wherein the optical resonator coil comprises antiresonant nodeless fiber; a resonator loop closure optics system; and wherein the antiresonant nodeless fiber has a length such that the resonant frequencies the optical resonator of the desired polarization state of light and of the undesired polarization state of light are separated by between a tenth of a free spectral range and nine tenths of a free spectral range to minimize gyroscope errors.
    Type: Grant
    Filed: April 13, 2018
    Date of Patent: October 22, 2019
    Assignee: Honeywell International Inc.
    Inventors: Glen A. Sanders, Clarence Eugene Laskoskie, Chellappan Narayanan, Lee K. Strandjord
  • Publication number: 20190212148
    Abstract: An optical resonator is provided. The optical resonator comprises: an optical resonator coil comprising a first port and a second port; wherein the optical resonator coil comprises antiresonant nodeless fiber; a resonator loop closure optics system; and wherein the antiresonant nodeless fiber has a length such that the resonant frequencies the optical resonator of the desired polarization state of light and of the undesired polarization state of light are separated by between a tenth of a free spectral range and nine tenths of a free spectral range to minimize gyroscope errors.
    Type: Application
    Filed: April 13, 2018
    Publication date: July 11, 2019
    Applicant: Honeywell International Inc.
    Inventors: Glen A. Sanders, Clarence Eugene Laskoskie, Chellappan Narayanan, Lee K. Strandjord
  • Patent number: 9252559
    Abstract: An optical-fiber filter system to narrow a linewidth and to reduce noise fluctuations of an optical beam is provided. The optical-fiber filter system includes an optical fiber having a first end-face and an opposing second end-face, the first end-face and the second end-face setting a fiber length; a fiber Bragg grating having a first reflectivity positioned at the first end-face; and a reflector having a second reflectivity positioned at the second end-face. When the optical beam at a first frequency is coupled from a laser into one of the first end-face or the second end-face, a resonant cavity is established at the first frequency between the fiber Bragg grating and the reflector while Brillouin scattered light shifted from the first frequency within the optical fiber is transmitted through the fiber Bragg grating.
    Type: Grant
    Filed: July 10, 2012
    Date of Patent: February 2, 2016
    Assignee: Honeywell International Inc.
    Inventors: Chellappan Narayanan, Glen A. Sanders, Lee K. Strandjord, Jianfeng Wu
  • Publication number: 20140204387
    Abstract: An optical-fiber filter system to narrow a linewidth and to reduce noise fluctuations of an optical beam is provided. The optical-fiber filter system includes an optical fiber having a first end-face and an opposing second end-face, the first end-face and the second end-face setting a fiber length; a fiber Bragg grating having a first reflectivity positioned at the first end-face; and a reflector having a second reflectivity positioned at the second end-face. When the optical beam at a first frequency is coupled from a laser into one of the first end-face or the second end-face, a resonant cavity is established at the first frequency between the fiber Bragg grating and the reflector while Brillouin scattered light shifted from the first frequency within the optical fiber is transmitted through the fiber Bragg grating.
    Type: Application
    Filed: July 10, 2012
    Publication date: July 24, 2014
    Applicant: HONEYWELL INTERNATIONAL INC.
    Inventors: Chellappan Narayanan, Glen A. Sanders, Lee K. Strandjord, Jianfeng Wu
  • Publication number: 20100284018
    Abstract: Effective relative intensity noise (RIN) subtraction systems and methods for improving ARW performance of a depolarized gyros. This invention taps the RIN detector light in the sensing loop, after the light transmits through the depolarizer and the coil but before it combines with the counter propagating lightwave. The tapped RIN lightwaves are polarized with pass-axis orientated in the same direction as that of the IOC, so that the RIN detector receives lightwaves with spectrum substantially identical to that of the rate detector, leading to more effective RIN subtraction.
    Type: Application
    Filed: May 11, 2009
    Publication date: November 11, 2010
    Applicant: HONEYWELL INTERNATIONAL INC.
    Inventors: Tiequn Qiu, Steven J. Sanders, Chellappan Narayanan
  • Publication number: 20080116361
    Abstract: Apparatus and method are provided for chemical and biological agent sensing. The sensing apparatus includes a resonator having a resonance frequency and one or more optical fiber coils. The optical fiber coil has a permeable cladding and an indicator embedded in the cladding that reacts to an agent (e.g., a chemical or biological substance). The resonator circulates light through the coil and produces a resonance shape centered at the resonance frequency and measured via the input light. A predetermined change in the resonance shape indicates a presence of the agent in the environment.
    Type: Application
    Filed: November 16, 2006
    Publication date: May 22, 2008
    Inventors: Glen A. Sanders, Chellappan Narayanan
  • Patent number: 6442311
    Abstract: Transmission characteristics of an optical device 200, fabricated from multiple layers 16, 27, 28 of silica-based glass on a silicon substrate 26, are modified by localized thermal treatment. The beam 501 of a carbon-dioxide (CO2) laser 510 is used to selectively soften the core and/or cladding material of a waveguide structure during or after the fabrication process. In one application, softening relieves the strain developed between the waveguide structure and the silicon substrate and substantially reduces or eliminates birefringence. In a second application, the CO2 laser is operated at another power level in order to modify the index of refraction. Changes in the index of refraction change the speed of light through a waveguide thereby changing the phase shift associated with the waveguide. In a third application, the CO2 laser is operated at yet another power level to increase the transmission loss of the waveguide.
    Type: Grant
    Filed: July 9, 1999
    Date of Patent: August 27, 2002
    Assignee: Agere Systems Guardian Corp.
    Inventors: Giovanni Barbarossa, Chellappan Narayanan
  • Patent number: 6055976
    Abstract: A method for preparing operative end faces of integrated circuit chips or dies utilizes a beveled cutting blade to impart a desired contact angle to the operative end faces of the chip. The method includes the steps of mounting feet on the chip, trimming the feet where necessary, mounting the chip on a fixture with tape, cutting the end faces, and removing the chip from the fixture.
    Type: Grant
    Filed: January 29, 1998
    Date of Patent: May 2, 2000
    Assignee: Lucent Technologies, Inc.
    Inventors: Scott Thomas Davies, Francis M. Mess, Chellappan Narayanan
  • Patent number: 5980120
    Abstract: Disclosed is an apparatus for testing an array of optical fibers. According to the invention, modulated light is projected through individual fibers of a fiber array onto a photo-sensitive position sensor. The photo-sensitive sensor will provide position information relative to the position of the light projected upon its surface to a system computer. The positions of the optical fibers within the array relative to each other may thus be found. A loop is introduced into the optical fibers to lower the wavelength at which the fiber is multi-moded. The actual positions of the optical fibers are compared to desired positions and the fiber array is accepted or rejected based on whether it meets predetermined limits.
    Type: Grant
    Filed: September 25, 1997
    Date of Patent: November 9, 1999
    Assignee: Lucent Technologies Inc.
    Inventor: Chellappan Narayanan
  • Patent number: 5978539
    Abstract: An optical interconnection device has a passive control mechanism for substantially eliminating thermal effects on optical properties of the apparatus Specifically, the interconnection apparatus includes a control material coupled to an optical circuit substrate, wherein the control material has a thermal expansion coefficient that is different than a substrate thermal expansion coefficient. In response to an increase or decrease an ambient temperature, the control material thermally expands or contracts at a different rate than the substrate to create a non-planar substrate distortion transmitted to the core portion, thereby creating a temperature independent optical path length within the optical core portion.
    Type: Grant
    Filed: October 3, 1997
    Date of Patent: November 2, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Scott T. Davies, Daren Li, Yuan P. Li, Chellappan Narayanan, Kevin G. Sullivan, Jianluo Zhang
  • Patent number: 5796906
    Abstract: An optical planar waveguide notch filter employs a waveguide with first, second and third regions. The first and third regions have structures for propagating an optical signal in a first transmission mode. The second region is located between the first and third regions and has a structure in which an optical signal propagates in the first transmission mode as well as at least one other higher order transmission mode. The structure of the second region further couples a particular wavelength band of the signal propagating in the first transmission mode to at least one of the other transmission modes. This coupling causes an attenuation of energy of such bandwidth in the signal propagating in the first transmission mode. As a result, the signal propagating from the second region to the third region in the first transmission mode is a notch filtered signal possessing an attenuation at the particular wavelength band.
    Type: Grant
    Filed: August 27, 1996
    Date of Patent: August 18, 1998
    Assignee: Lucent Technologies Inc.
    Inventors: Chellappan Narayanan, Herman Melvin Presby
  • Patent number: 5768452
    Abstract: A method is provided of trimming the optical coupling ratio of an optical coupler to a prescribed value. The optical coupler is formed from a plurality of waveguides which each include a core and cladding. In accordance with the method, an irradiation energy is selected that is absorbed by portions of the waveguides located in a coupling region. A dosage of radiation is applied to the waveguide portions at least sufficient to adjust the optical coupling ratio to the prescribed value. The radiation, which may be absorbed by the cladding and/or the core of the waveguides, causes a change in the refractive index difference between the core and cladding of the waveguides. This change in the refractive index difference will result in a change in the optical coupling ratio of the device.
    Type: Grant
    Filed: April 17, 1996
    Date of Patent: June 16, 1998
    Assignee: Lucent Technologies Inc.
    Inventors: Robert Michael Atkins, Benjamin Irvin Greene, Chellappan Narayanan, Herman Melvin Presby
  • Patent number: 5768457
    Abstract: In many assembly applications of optical arrays, a bridging member is bonded to the arrays to hold them securely. It has been found that a pad made of layers of glass and silicon provides an efficient heat transmitting structure for this purpose. Because glass is absorbent to laser radiation at 10.6 .mu.m, it absorbs all the incident laser radiation, and imparts the heat generated to the silicon, which transmits it uniformly over its entire surface. The heat can then be used to melt solder or to heat-cure an adhesive, thereby affecting a robust mechanical bond in an efficient and rapid manner.
    Type: Grant
    Filed: November 30, 1995
    Date of Patent: June 16, 1998
    Assignee: Lucent Technologies Inc.
    Inventors: Chellappan Narayanan, Herman Melvin Presby
  • Patent number: 5588085
    Abstract: A method of making a silicate optical waveguide structure for transforming an optical beam of a first modal spot size to a beam of a second modal spot size includes the step of selecting an irradiation energy which is at least partially absorbed by the cladding of the structure. A variable dosage of radiation is then provided along the length of the structure. The radiation has an energy equal to the selected irradiation energy so that a refractive index change of the cladding is greater than a refractive index change of the core.
    Type: Grant
    Filed: April 17, 1996
    Date of Patent: December 24, 1996
    Assignee: Lucent Technologies Inc.
    Inventors: Benjamin I. Greene, Chellappan Narayanan, Herman M. Presby