Patents by Inventor Pradip Mitra

Pradip Mitra 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: 7485097
    Abstract: A method of and apparatus for detecting diseased tissue based upon infrared imaging in two different bands of infrared wavelengths is described. The use of two series of infrared images taken in two different bands of infrared wavelengths increases sensitivity to the subtle temperature changes caused by diseased skin and tissue, especially in the case of cancerous tissue. By sensing skin temperature, the homogeneity thereof, the time variations thereof and the correlation between the two series of infrared images, the present invention decreases the rate of false positives and false negatives. The increased discrimination due to two series of infrared images allows for reliable detection of diseased or cancerous tissue even in the presence of skin tone variations such as birthmarks, tattoos and freckles. The present invention finds special application in the field of breast cancer detection where subtle skin temperature variations may readily be sensed using two series of infrared images.
    Type: Grant
    Filed: March 14, 2007
    Date of Patent: February 3, 2009
    Assignee: Lockheed Martin Corporation
    Inventor: Pradip Mitra
  • Publication number: 20070173707
    Abstract: A method of and apparatus for detecting diseased tissue based upon infrared imaging in two different bands of infrared wavelengths is described. The use of two series of infrared images taken in two different bands of infrared wavelengths increases sensitivity to the subtle temperature changes caused by diseased skin and tissue, especially in the case of cancerous tissue. By sensing skin temperature, the homogeneity thereof, the time variations thereof and the correlation between the two series of infrared images, the present invention decreases the rate of false positives and false negatives. The increased discrimination due to two series of infrared images allows for reliable detection of diseased or cancerous tissue even in the presence of skin tone variations such as birthmarks, tattoos and freckles. The present invention finds special application in the field of breast cancer detection where subtle skin temperature variations may readily be sensed using two series of infrared images.
    Type: Application
    Filed: March 14, 2007
    Publication date: July 26, 2007
    Applicant: LOCKHEED MARTIN CORPORATION
    Inventor: Pradip Mitra
  • Publication number: 20070167831
    Abstract: A method of and apparatus for detecting diseased tissue based upon infrared imaging in two different bands of infrared wavelengths is described. The use of two series of infrared images taken in two different bands of infrared wavelengths increases sensitivity to the subtle temperature changes caused by diseased skin and tissue, especially in the case of cancerous tissue. By sensing skin temperature, the homogeneity thereof, the time variations thereof and the correlation between the two series of infrared images, the present invention decreases the rate of false positives and false negatives. The increased discrimination due to two series of infrared images allows for reliable detection of diseased or cancerous tissue even in the presence of skin tone variations such as birthmarks, tattoos and freckles. The present invention finds special application in the field of breast cancer detection where subtle skin temperature variations may readily be sensed using two series of infrared images.
    Type: Application
    Filed: March 14, 2007
    Publication date: July 19, 2007
    Applicant: LOCKHEED MARTIN CORPORATION
    Inventor: Pradip Mitra
  • Publication number: 20070161923
    Abstract: A method of and apparatus for detecting diseased tissue based upon infrared imaging in two different bands of infrared wavelengths is described. The use of two series of infrared images taken in two different bands of infrared wavelengths increases sensitivity to the subtle temperature changes caused by diseased skin and tissue, especially in the case of cancerous tissue. By sensing skin temperature, the homogeneity thereof, the time variations thereof and the correlation between the two series of infrared images, the present invention decreases the rate of false positives and false negatives. The increased discrimination due to two series of infrared images allows for reliable detection of diseased or cancerous tissue even in the presence of skin tone variations such as birthmarks, tattoos and freckles. The present invention finds special application in the field of breast cancer detection where subtle skin temperature variations may readily be sensed using two series of infrared images.
    Type: Application
    Filed: March 14, 2007
    Publication date: July 12, 2007
    Applicant: LOCKHEED MARTIN CORPORATION
    Inventor: Pradip Mitra
  • Publication number: 20070156062
    Abstract: A method of and apparatus for detecting diseased tissue based upon infrared imaging in two different bands of infrared wavelengths is described. The use of two series of infrared images taken in two different bands of infrared wavelengths increases sensitivity to the subtle temperature changes caused by diseased skin and tissue, especially in the case of cancerous tissue. By sensing skin temperature, the homogeneity thereof, the time variations thereof and the correlation between the two series of infrared images, the present invention decreases the rate of false positives and false negatives. The increased discrimination due to two series of infrared images allows for reliable detection of diseased or cancerous tissue even in the presence of skin tone variations such as birthmarks, tattoos and freckles. The present invention finds special application in the field of breast cancer detection where subtle skin temperature variations may readily be sensed using two series of infrared images.
    Type: Application
    Filed: March 14, 2007
    Publication date: July 5, 2007
    Applicant: LOCKHEED MARTIN CORPORATION
    Inventor: Pradip Mitra
  • Patent number: 7214195
    Abstract: A method of and apparatus for detecting diseased tissue based upon infrared imaging in two different bands of infrared wavelengths is described. The use of two series of infrared images taken in two different bands of infrared wavelengths increases sensitivity to the subtle temperature changes caused by diseased skin and tissue, especially in the case of cancerous tissue. By sensing skin temperature, the homogeneity thereof, the time variations thereof and the correlation between the two series of infrared images, the present invention decreases the rate of false positives and false negatives. The increased discrimination due to two series of infrared images allows for reliable detection of diseased or cancerous tissue even in the presence of skin tone variations such as birthmarks, tattoos and freckles. The present invention finds special application in the field of breast cancer detection where subtle skin temperature variations may readily be sensed using two series of infrared images.
    Type: Grant
    Filed: July 23, 2003
    Date of Patent: May 8, 2007
    Assignee: Lockheed Martin Corporation
    Inventor: Pradip Mitra
  • Publication number: 20070029485
    Abstract: An avalanche photodiode is operated in avalanche mode at a selected reverse bias that achieves high gain and a reduced gain normalized dark current.
    Type: Application
    Filed: August 3, 2005
    Publication date: February 8, 2007
    Inventors: Jeffrey Beck, Pradip Mitra, Chang-Feng Wan, Michael Kinch
  • Patent number: 7135698
    Abstract: A multi-spectral super-pixel photodetector for detecting four or more different bands of infrared radiation is described. The super-pixel photodetector includes two or more sub-pixel photodetectors, each of which includes a diffractive resonant optical cavity that resonates at two or more infrared radiation bands of interest. By detecting infrared radiation at two or more different applied biases and by generating a spectral response curve for each of the sub-pixel photodetectors at each of these biases, the response to each of the individual bands of infrared radiation can be calculated. The response to each band of infrared radiation can be found by deconvolving the response at each bias. The super-pixel photodetector finds use in military and medical imaging applications and can cover a broad portion of the infrared spectrum.
    Type: Grant
    Filed: December 5, 2002
    Date of Patent: November 14, 2006
    Assignee: Lockheed Martin Corporation
    Inventor: Pradip Mitra
  • Patent number: 7041983
    Abstract: The described embodiments of the present invention include a method for forming a radiation detector. A radiation absorption layer is formed on a substrate. A wider bandgap layer is formed on the radiation absorption layer. A passivation layer is formed on the wider bandgap layer. A doping layer is formed on the passivation layer. The doping layer is then patterned and dopant is driven from the patterned doping layer into the junction layer and the radiation absorption layer to form a doped region. The passivation layer is patterned to expose the doped region and an electrical contact to the doped region is formed.
    Type: Grant
    Filed: October 12, 2001
    Date of Patent: May 9, 2006
    Assignee: Lockheed Martin Corporation
    Inventor: Pradip Mitra
  • Patent number: 6920290
    Abstract: An array of diffraction grating coupled infrared photodetectors is coupled to corresponding high-speed amplifiers for creating a multiple channel high speed receiver for an optical communication system. Each photodetector includes a three-dimensional diffractive resonant optical cavity formed by a diffraction grating that resonates over a narrow range of wavelengths. By creating different resonant optical cavities, the receiver detects each optical channel individually, thereby simplifying receiver design. The receiver finds ready application in systems based upon high power CO2 lasers and semiconductor lasers such as quantum cascade lasers allowing extremely long line of sight communication, such as between satellites. Other applications include ship to ship or ground to missile communications. These applications will benefit from increased jamming resistance and security.
    Type: Grant
    Filed: July 11, 2001
    Date of Patent: July 19, 2005
    Assignee: Lockheed Martin Corporation
    Inventor: Pradip Mitra
  • Patent number: 6897447
    Abstract: A multi-spectral photodetector for detecting two or more different bands of infrared radiation is described. The photodetector includes a diffractive resonant optical cavity that resonates at the two or more infrared radiation bands of interest. By detecting infrared radiation at two or more discrete applied biases and by generating a spectral response curve for the photodetector at each of these biases, the response to each of the individual bands of infrared radiation can be calculated. The response to each band of infrared radiation can be found by deconvolving the response at each bias. The photodetector finds many uses including military and medical imaging applications and can cover a broad portion of the infrared spectrum.
    Type: Grant
    Filed: December 5, 2002
    Date of Patent: May 24, 2005
    Assignee: Lockheed Martin Corporation
    Inventor: Pradip Mitra
  • Patent number: 6882409
    Abstract: A multi-spectral detector for use in a passive/active system and a method for use in identifying an object in a field of view are disclosed. The multi-spectral detection system comprises an optically dispersive element, a detector array, and an integrated circuit. The optically dispersive element is capable of separating received LADAR radiation and radiation received from a scene into a plurality of spectral components and distributing the separated spectral components; and a detector array. The detector array includes a plurality of detectors capable of detecting the LADAR radiation; and a plurality of detectors capable of detecting the spectral components of the scene radiation. The integrated circuit is capable of generating a plurality of electrical signals representative of predetermined characteristics of the detected LADAR radiation and the detected spectral components.
    Type: Grant
    Filed: June 25, 2003
    Date of Patent: April 19, 2005
    Assignee: Lockheed Martin Corporation
    Inventors: Bruno J. Evans, Pradip Mitra
  • Publication number: 20050068517
    Abstract: A multi-spectral detector for use in a passive/active system and a method for use in identifying an object in a field of view are disclosed. The multi-spectral detection system comprises an optically dispersive element, a detector array, and an integrated circuit. The optically dispersive element is capable of separating received LADAR radiation and radiation received from a scene into a plurality of spectral components and distributing the separated spectral components; and a detector array. The detector array includes a plurality of detectors capable of detecting the LADAR radiation; and a plurality of detectors capable of detecting the spectral components of the scene radiation. The integrated circuit is capable of generating a plurality of electrical signals representative of predetermined characteristics of the detected LADAR radiation and the detected spectral components.
    Type: Application
    Filed: June 25, 2003
    Publication date: March 31, 2005
    Inventors: Bruno Evans, Pradip Mitra
  • Publication number: 20050020924
    Abstract: A method of and apparatus for detecting diseased tissue based upon infrared imaging in two different bands of infrared wavelengths is described. The use of two series of infrared images taken in two different bands of infrared wavelengths increases sensitivity to the subtle temperature changes caused by diseased skin and tissue, especially in the case of cancerous tissue. By sensing skin temperature, the homogeneity thereof, the time variations thereof and the correlation between the two series of infrared images, the present invention decreases the rate of false positives and false negatives. The increased discrimination due to two series of infrared images allows for reliable detection of diseased or cancerous tissue even in the presence of skin tone variations such as birthmarks, tattoos and freckles. The present invention finds special application in the field of breast cancer detection where subtle skin temperature variations may readily be sensed using two series of infrared images.
    Type: Application
    Filed: July 23, 2003
    Publication date: January 27, 2005
    Inventor: Pradip Mitra
  • Patent number: 6828642
    Abstract: A diffraction grating coupled infrared photodetector for providing high performance detection of infrared radiation is described. The photodetector includes a three-dimensional diffractive resonant optical cavity formed by a diffraction grating that resonates over a range of infrared radiation wavelengths. By placing a limited number of p/n junctions throughout the photodetector, the photodetector thermal noise is reduced due to the reduction in junction area. By retaining signal response and reducing the noise, the sensitivity increases at a given operating temperature when compared to traditional photovoltaic and photoconductive infrared photodetectors up to the background limit. The photodetector device design can be used with a number of semiconductor material systems, can form one- and two-dimensional focal plane arrays, and can readily be tuned for operation in the long wavelength infrared and the very long wavelength infrared where sensitivity and noise improvements are most significant.
    Type: Grant
    Filed: April 17, 2001
    Date of Patent: December 7, 2004
    Assignee: Lockhead Martin Corporation
    Inventors: Lewis T. Claiborne, Pradip Mitra
  • Patent number: 6775067
    Abstract: A method and apparatus for stretching a pulse, shaping a stretched pulse, and modeling a stretched and/or shaped pulse are disclosed. An etalon has a port, a partially reflective surface, and a fully reflective surface. A base pulse is introduced into the etalon, and a plurality of portions of the base pulse propagating from the etalon are collected. The collected portions are then combined to generate a stretched pulse whose width is proportional to the width of the base pulse. This can be modeled by assigning a transmission factor value to each one of a plurality of taps and a reflection factor value to each one of the taps, excepting only one tap. A transport delay for is assigned to each tap to which a reflection factor value was assigned, wherein the transport delay is proportional to the width of a base pulse.
    Type: Grant
    Filed: June 6, 2002
    Date of Patent: August 10, 2004
    Assignee: Lockheed Martin Corporation
    Inventors: James R. Wood, Pradip Mitra
  • Publication number: 20040108461
    Abstract: A multi-spectral photodetector for detecting two or more different bands of infrared radiation is described. The photodetector includes a diffractive resonant optical cavity that resonates at the two or more infrared radiation bands of interest. By detecting infrared radiation at two or more discrete applied biases and by generating a spectral response curve for the photodetector at each of these biases, the response to each of the individual bands of infrared radiation can be calculated. The response to each band of infrared radiation can be found by deconvolving the response at each bias. The photodetector finds many uses including military and medical imaging applications and can cover a broad portion of the infrared spectrum.
    Type: Application
    Filed: December 5, 2002
    Publication date: June 10, 2004
    Applicant: LOCKHEED MARTIN CORPORATION
    Inventor: Pradip Mitra
  • Publication number: 20040108564
    Abstract: A multi-spectral super-pixel photodetector for detecting four or more different bands of infrared radiation is described. The super-pixel photodetector includes two or more sub-pixel photodetectors, each of which includes a diffractive resonant optical cavity that resonates at two or more infrared radiation bands of interest. By detecting infrared radiation at two or more different applied biases and by generating a spectral response curve for each of the sub-pixel photodetectors at each of these biases, the response to each of the individual bands of infrared radiation can be calculated. The response to each band of infrared radiation can be found by deconvolving the response at each bias. The super-pixel photodetector finds use in military and medical imaging applications and can cover a broad portion of the infrared spectrum.
    Type: Application
    Filed: December 5, 2002
    Publication date: June 10, 2004
    Applicant: LOCKHEED MARTIN CORPORATION
    Inventor: Pradip Mitra
  • Publication number: 20030227686
    Abstract: A method and apparatus for stretching a pulse, shaping a stretched pulse, and modeling a stretched and/or shaped pulse are disclosed. An etalon comprises a port, a partially reflective surface, and a fully reflective surface. A base pulse is introduced into the etalon, and a plurality of portions of the base pulse propagating from the etalon are collected. The collected portions are then combined to generate a stretched pulse whose width is proportional to the width of the base pulse. This can be modeled by assigning a transmission factor value to each one of a plurality of taps and a reflection factor value to each one of the taps, excepting only one tap. A transport delay for is assigned to each tap to which a reflection factor value was assigned, wherein the transport delay is proportional to the width of a base pulse.
    Type: Application
    Filed: June 6, 2002
    Publication date: December 11, 2003
    Inventors: James R. Wood, Pradip Mitra
  • Publication number: 20030071221
    Abstract: The described embodiments of the present invention include a method for forming a radiation detector, including the steps of: forming a radiation absorption layer on a substrate; forming a wider bandgap layer on the radiation absorption layer; forming a passivation layer on the wider bandgap layer; forming a doping layer on the passivation layer; patterning the doping layer; driving dopant from the patterned doping layer into the junction layer and the radiation absorption layer to form a doped region; patterning the passivation layer to expose the doped region; and forming an electrical contact to the doped region.
    Type: Application
    Filed: October 12, 2001
    Publication date: April 17, 2003
    Applicant: LOCKHEED MARTIN CORPORATION
    Inventor: Pradip Mitra