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).
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Patent number: 7485097Abstract: 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: GrantFiled: March 14, 2007Date of Patent: February 3, 2009Assignee: Lockheed Martin CorporationInventor: Pradip Mitra
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Publication number: 20070173707Abstract: 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: ApplicationFiled: March 14, 2007Publication date: July 26, 2007Applicant: LOCKHEED MARTIN CORPORATIONInventor: Pradip Mitra
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Publication number: 20070167831Abstract: 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: ApplicationFiled: March 14, 2007Publication date: July 19, 2007Applicant: LOCKHEED MARTIN CORPORATIONInventor: Pradip Mitra
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Publication number: 20070161923Abstract: 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: ApplicationFiled: March 14, 2007Publication date: July 12, 2007Applicant: LOCKHEED MARTIN CORPORATIONInventor: Pradip Mitra
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Publication number: 20070156062Abstract: 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: ApplicationFiled: March 14, 2007Publication date: July 5, 2007Applicant: LOCKHEED MARTIN CORPORATIONInventor: Pradip Mitra
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Patent number: 7214195Abstract: 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: GrantFiled: July 23, 2003Date of Patent: May 8, 2007Assignee: Lockheed Martin CorporationInventor: Pradip Mitra
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Publication number: 20070029485Abstract: 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: ApplicationFiled: August 3, 2005Publication date: February 8, 2007Inventors: Jeffrey Beck, Pradip Mitra, Chang-Feng Wan, Michael Kinch
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Patent number: 7135698Abstract: 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: GrantFiled: December 5, 2002Date of Patent: November 14, 2006Assignee: Lockheed Martin CorporationInventor: Pradip Mitra
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Patent number: 7041983Abstract: 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: GrantFiled: October 12, 2001Date of Patent: May 9, 2006Assignee: Lockheed Martin CorporationInventor: Pradip Mitra
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Patent number: 6920290Abstract: 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: GrantFiled: July 11, 2001Date of Patent: July 19, 2005Assignee: Lockheed Martin CorporationInventor: Pradip Mitra
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Patent number: 6897447Abstract: 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: GrantFiled: December 5, 2002Date of Patent: May 24, 2005Assignee: Lockheed Martin CorporationInventor: Pradip Mitra
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Patent number: 6882409Abstract: 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: GrantFiled: June 25, 2003Date of Patent: April 19, 2005Assignee: Lockheed Martin CorporationInventors: Bruno J. Evans, Pradip Mitra
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Publication number: 20050068517Abstract: 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: ApplicationFiled: June 25, 2003Publication date: March 31, 2005Inventors: Bruno Evans, Pradip Mitra
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Publication number: 20050020924Abstract: 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: ApplicationFiled: July 23, 2003Publication date: January 27, 2005Inventor: Pradip Mitra
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Patent number: 6828642Abstract: 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: GrantFiled: April 17, 2001Date of Patent: December 7, 2004Assignee: Lockhead Martin CorporationInventors: Lewis T. Claiborne, Pradip Mitra
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Patent number: 6775067Abstract: 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: GrantFiled: June 6, 2002Date of Patent: August 10, 2004Assignee: Lockheed Martin CorporationInventors: James R. Wood, Pradip Mitra
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Publication number: 20040108461Abstract: 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: ApplicationFiled: December 5, 2002Publication date: June 10, 2004Applicant: LOCKHEED MARTIN CORPORATIONInventor: Pradip Mitra
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Publication number: 20040108564Abstract: 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: ApplicationFiled: December 5, 2002Publication date: June 10, 2004Applicant: LOCKHEED MARTIN CORPORATIONInventor: Pradip Mitra
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Publication number: 20030227686Abstract: 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: ApplicationFiled: June 6, 2002Publication date: December 11, 2003Inventors: James R. Wood, Pradip Mitra
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Publication number: 20030071221Abstract: 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: ApplicationFiled: October 12, 2001Publication date: April 17, 2003Applicant: LOCKHEED MARTIN CORPORATIONInventor: Pradip Mitra