Abstract: A rectal near infrared (NIR) scanning polarization imaging system uses NIR Photonic Prostatoscopy Analyzer (NIRPPA) for prostate cancer detection using light. The NIRPPA consists of a portable rectal NIR scanning polarization imaging unit and an optical fiber-based rectal probe capable of recording sets of 2D images of a prostate through rectum at different wavelengths and depths and obtaining a three dimensional (3D) image of the prostate and 3D locations of abnormal tissue inside the prostate. Diode lasers/light emission diodes (LEDs) with selected emitting wavelengths are used in the NIR spectral range from 650 nm to 2,400 nm corresponding to the four tissue optical windows (#I, 650 nm-950 nm; #II, 1,100 nm-1,350 nm; #III, 1,600 nm-1,870 nm; and #IV, 2,100 nm-2,300 nm). The fingerprint absorptions of water (H2O), Oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) in the prostate are used as native biomarkers for prostate cancer detection.

Abstract: A method detects the degree of spoilage of food by exposing a food sample to an excitation wave having a first wavelength of about 340 nm or about 380 nm, wherein the excitation wave has a bandwidth of 40 nm or less. The excitation wave is permitted to interact with the food sample and return emission spectra. A detector detects the emission spectra. A predetermined threshold value is established which defines when a food sample is or is not spoiled. The emission spectra is analyzed at a second wavelength of about 400 nm, about 450 nm or about 530 nm to provide a test or measured value of the emission spectra indicative of the degree of spoilage of the food sample. Whether or not a food sample is spoiled beyond the predetermined threshold is determined by comparing the measured value to the predetermined threshold value.

Abstract: A rectal near infrared (NIR) scanning polarization imaging system uses NIR Photonic Prostatoscopy Analyzer (NIRPPA) for prostate cancer detection using light. The NIRPPA consists of a portable rectal NIR scanning polarization imaging unit and an optical fiber-based rectal probe capable of recording sets of 2D images of a prostate through rectum at different wavelengths and depths and obtaining a three dimensional (3D) image of the prostate and 3D locations of abnormal tissue inside the prostate. Diode lasers/light emission diodes (LEDs) with selected emitting wavelengths are used in the NIR spectral range from 650 nm to 2,400 nm corresponding to the four tissue optical windows (#I, 650 nm-950 nm; #II, 1,100 nm-1,350 nm; #III, 1,600 nm-1,870 nm; and #IV, 2,100 nm-2,300 nm). The fingerprint absorptions of water (H2O), Oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) in the prostate are used as native biomarkers for prostate cancer detection.

Abstract: A method detects the degree of spoilage of food by exposing a food sample to an excitation wave having a first wavelength of about 340 nm or about 380 nm, wherein the excitation wave has a bandwidth of 40 nm or less. The excitation wave is permitted to interact with the food sample and return emission spectra. A detector detects the emission spectra. A predetermined threshold value is established which defines when a food sample is or is not spoiled. The emission spectra is analyzed at a second wavelength of about 400 nm, about 450 nm or about 530 nm to provide a test or measured value of the emission spectra indicative of the degree of spoilage of the food sample. Whether or not a food sample is spoiled beyond the predetermined threshold is determined by comparing the measured value to the predetermined threshold value.

Abstract: An apparatus and method of use for detecting vulnerable plaque (VP) in arterial walls is provided. The method includes measuring whether the Raman spectrum of adipose (lipid) tissue signal is present in a Raman signal from aortic intimal wall tissue. The Raman vibration modes for VP are strong bands at about 1435 cm?1, about 2850 cm?1, and about 2892 cm?1 and will be present when the aortic intimal wall tissue is thin.

Abstract: Spectral optical imaging at one or more key water absorption fingerprint wavelengths measures the difference in water content between a region of cancerous or precancerous tissue and a region of normal tissue. Water content is an important diagnostic parameter because cancerous and precancerous tissues have different water content than normal tissues. Key water absorption wavelengths include at least one of 980 nanometers (nm), 1195 nm, 1456 nm, 1944 nm, 2880 nm to 3360 nm, and 4720 nm. In the range of 400 nm to 6000 nm, one or more points of negligible water absorption are used as reference points for a comparison with one or more key neighboring water absorption wavelengths. Different images are generated using at least two wavelengths, including a water absorption wavelength and a negligible water absorption wavelength, to yield diagnostic information relevant for classifying a tissue region as cancerous, precancerous, or normal.

Abstract: A system for detecting ice formation on metal, painted metal and other material surfaces can include a transparent window having an exterior surface upon which ice can form; a light source and optics configured and arranged to illuminate the exterior surface of the window from behind the exterior surface; and a detector and optics configured and arranged to receive light backscattered by the exterior surface and any ice disposed on the exterior surface and determine the thickness of the ice layer. For example, the system can be used with aircraft by placing one or more windows in the wings of the aircraft. The system is used for a novel optical method for real-time on-board detection and warning of ice formation on surfaces of airplanes, unmanned aerial vehicles (UAVs), and other vehicles and stationary structures to improve their safety and operation.

Abstract: A system for detecting ice formation on metal, painted metal and other material surfaces can include a transparent window having an exterior surface upon which ice can form; a light source and optics configured and arranged to illuminate the exterior surface of the window from behind the exterior surface; and a detector and optics configured and arranged to receive light backscattered by the exterior surface and any ice disposed on the exterior surface and determine the thickness of the ice layer. For example, the system can be used with aircraft by placing one or more windows in the wings of the aircraft. The system is used for a novel optical method for real-time on-board detection and warning of ice formation on surfaces of airplanes, unmanned aerial vehicles (UAVs), and other vehicles and stationary structures to improve their safety and operation.

Abstract: The design and operation of a p-i-n device, operating in a sequential resonant tunneling condition for use as a photodetector and an optically pumped emitter, is disclosed. The device contains III-nitride multiple-quantum-well (MQW) layers grown between a III-nitride p-n junction. Transparent ohmic contacts are made on both p and n sides. The device operates under a certain electrical bias that makes the energy level of the first excitation state in each well layer correspond with the energy level of the ground state in the adjoining well layer. The device works as a high-efficiency and high-speed photodetector with photo-generated carriers transported through the active MQW region by sequential resonant tunneling. In a sequential resonant tunneling condition, the device also works as an optically pumped infrared emitter that emits infrared photons with energy equal to the energy difference between the first excitation state and the ground state in the MQWs.

Abstract: The design and operation of a p-i-n device, operating in a sequential resonant tunneling condition for use as a photodetector and an optically pumped emitter, is disclosed. The device contains III-nitride multiple-quantum-well (MQW) layers grown between a III-nitride p-n junction. Transparent ohmic contacts are made on both p and n sides. The device operates under a certain electrical bias that makes the energy level of the first excitation state in each well layer correspond with the energy level of the ground state in the adjoining well layer. The device works as a high-efficiency and high-speed photodetector with photo-generated carriers transported through the active MQW region by sequential resonant tunneling. In a sequential resonant tunneling condition, the device also works as an optically pumped infrared emitter that emits infrared photons with energy equal to the energy difference between the first excitation state and the ground state in the MQWs.

Abstract: Spectral optical imaging at one or more key water absorption fingerprint wavelengths measures the difference in water content between a region of cancerous or precancerous tissue and a region of normal tissue. Water content is an important diagnostic parameter because cancerous and precanerous tissues have different water content than normal tissues. Key water absorption wavelengths include at least one of 980 nanometers (nm), 1195 nm, 1456 nm, 1944 nm, 2880 nm to 3360 nm, and 4720 nm. In the range of 400 nm to 6000 nm, one or more points of negligible water absorption are used as reference points for a comparison with one or more key neighboring water absorption wavelengths. Different images are generated using at least two wavelengths, including a water absorption wavelength and a negligible water absorption wavelength, to yield diagnostic information relevant for classifying a tissue region as cancerous, precancerous, or normal.

Abstract: The present invention provides systems and methods for non-destructively detecting material abnormalities beneath a coated surface, comprising a mid-infrared (MIR) illumination unit for illuminating an area of the coated surface, and an MIR 2-D imager, which includes an MIR CCD or CMOS camera, for capturing an image of a material abnormalities under the illuminated area of the coated surface. In addition, the system may further comprise a scanning unit for moving the system to a next area.

Abstract: Spectral optical imaging at one or more key water absorption fingerprint wavelengths measures the difference in water content between a region of cancerous or precancerous tissue and a region of normal tissue. Water content is an important diagnostic parameter because cancerous and precanerous tissues have different water content than normal tissues. Key water absorption wavelengths include at least one of 980 nanometers (nm), 1195 nm, 1456 nm, 1944 nm, 2880 nm to 3360 nm, and 4720 nm. In the range of 400 nm to 6000 nm, one or more points of negligible water absorption are used as reference points for a comparison with one or more key neighboring water absorption wavelengths. Different images are generated using at least two wavelengths, including a water absorption wavelength and a negligible water absorption wavelength, to yield diagnostic information relevant for classifying a tissue region as cancerous, precancerous, or normal.

Abstract: The present invention provides systems and methods for non-destructively detecting material abnormalities beneath a coated surface, comprising a mid-infrared (MIR) detection unit for illuminating an area of the coated surface and detecting light reflected from the illuminated area of the coated surface, and a processing unit for producing an image from optical characteristics received from the MIR detection unit. In addition, the system may further comprise a scanning unit for moving the MIR detection unit to a next area.

Abstract: The design and operation of a p-i-n device, operating in a sequential resonant tunneling condition for use as a photodetector and an optically pumped emitter, is disclosed. The device contains III-nitride multiple-quantum-well (MQW) layers grown between a III-nitride p-n junction. Transparent ohmic contacts are made on both p and n sides. The device operates under a certain electrical bias that makes the energy level of the first excitation state in each well layer correspond with the energy level of the ground state in the adjoining well layer. The device works as a high-efficiency and high-speed photodetector with photo-generated carriers transported through the active MQW region by sequential resonant tunneling. In a sequential resonant tunneling condition, the device also works as an optically pumped infrared emitter that emits infrared photons with energy equal to the energy difference between the first excitation state and the ground state in the MQWs.

Abstract: The present invention provides systems and methods for non-destructively detecting material abnormalities beneath a coated surface, comprising a mid-infrared (MIR) illumination unit for illuminating an area of the coated surface, and an MIR 2-D imager, which includes an MIR CCD or CMOS camera, for capturing an image of a material abnormalities under the illuminated area of the coated surface. In addition, the system may further comprise a scanning unit for moving the system to a next area.

Abstract: The present invention provides systems and methods for non-destructively detecting material abnormalities beneath a coated surface, comprising a mid-infrared (MIR) detection unit for illuminating an area of the coated surface and detecting light reflected from the illuminated area of the coated surface, and a processing unit for producing an image from optical characteristics received from the MIR detection unit. In addition, the system may further comprise a scanning unit for moving the MIR detection unit to a next area.

Abstract: A method and system for examining biological materials using low-power cw excitation Raman spectroscopy. A low-power continuous wave (cw) pump laser beam and a low-power cw Stokes (or anti-Stokes) probe laser beam simultaneously illuminate a biological material and traverse the biological material in collinearity. The pump beam, whose frequency is varied, is used to induce Raman emission from the biological material. The intensity of the probe beam, whose frequency is kept constant, is monitored as it leaves the biological material. When the difference between the pump and probe excitation frequencies is equal to a Raman vibrational mode frequency of the biological material, the weak probe signal becomes amplified by one or more orders of magnitude (typically up to about 104-106) due to the Raman emission from the pump beam.

Abstract: Imaging of objects within tissue is enhanced by applying a contrast agent to a sample to be imaged to augment the emissions from an object, thereby forming a luminous object. The tissue is then illuminated and two image signals are recorded. The contrast agent is selected to bind to the object and provide spectral characteristics significantly different from that of the tissue for the two recorded image signals. The two image signals are subtracted to substantially minimize an image component resulting from the tissue and enhance an image component from the luminous object. The imaging methods and apparatus are particularly well suited for medical imaging where the object is diseased tissue such as tumors.

Abstract: A method and system for examining biological materials using low-power cw excitation Raman spectroscopy. In accordance with the teachings of the invention, a low-power continuous wave (cw) pump laser beam and a low-power cw Stokes (or anti-Stokes) probe laser beam simultaneously illuminate a biological material and traverse the biological material in collinearity. The pump beam, whose frequency is varied, is used to induce Raman emission from the biological material. The intensity of the probe beam, whose frequency is kept constant, is monitored as it leaves the biological material. When the difference between the pump and probe excitation frequencies is equal to a Raman vibrational mode frequency of the biological material, the weak probe signal becomes amplified by one or more orders of magnitude (typically up to about 10.sup.4 -10.sup.6) due to the Raman emission from the pump beam.