Abstract: Optical methods and devices for the thermal detection and imaging of infrared, sub-millimeter, millimeter and high energy radiation, wherein the thermal mass of the detector is minimized by the use of microscopic photoluminescent temperature probes having a weight mass which can be of the order of 10?11 grams or smaller. Used for detection of high energy radiation, including quantum calorimetry, said temperature probes allow non-contact measurements free of electrical sources of noise like Johnson noise or Joule heating.

Abstract: Optical methods and devices for measuring temperature and a second physical parameter, using a single photoluminescent probe material comprised of a single luminophor, and methods and devices for determining temperature-corrected values of said second physical parameter, which can be an oxygen or air pressure or a parameter chosen from the group comprising an electrical current, a magnetic field and an electrical field or voltage. The luminophor is excited sequentially by a first excitation light of chosen first wavelengths and intensity P1 which generates a first luminescence light of intensity I1, and a second excitation light of chosen second wavelengths and intensity P2 which generates a second luminescence light of intensity I2. The ratio (I2.P1/I1.P2) varies substantially in a known manner with varying temperature, substantially independent of the magnitude of said second physical parameter, thus providing a temperature correction factor to the measurement of said second physical parameter.

Abstract: Optical methods and devices for measuring temperature and a secong physical parameter, using a single photoluminescent probe material comprised of a single luminophor, and methods and devices for determining temperature-corrected values of said second physical parameter, which can be an oxygen or air pressure or a parameter chosen from the group comprising an electrical current, a magnetic field and an electrical field or voltage. The luminophor is excited sequentially by a first excitation light of chosen first wavelengths and intensity P1 which generates a first luminescence light of intensity I1, and a second excitation light of chosen second wavelengths and intensity P2 which generates a second luminescence light of intensity I2. The ratio (I2.P1/I1.P2) varies substantially in a known manner with varying temperature, substantially independent of the magnitude of said second physical parameter, thus providing a temperature correction factor to the measurement of said second physical parameter.

Abstract: Method and devices for measuring spot temperatures and surface temperature distributions using a luminophor, and method and devices for determining temperature-corrected oxygen or surface air pressure distributions using the same oxygen-sensitive luminophor. The luminophor is excited sequentially by a first light of wavelengths &lgr;1 and intensity P1 and a second light of wavelengths &lgr;v and intensity PT·, generating a first luminescence light of intensity I1 and a second luminescence light of intensity IT, respectively. The absorption of light of wavelength &lgr;v is substantially temperature-dependent in such a manner that the ratio (IT·P1/I1·PT) increases substantially in a known manner with increasing temperature, substantially independent of any oxygen pressure, and the oxygen pressure can be determined as a function of the luminescence decay time.

Abstract: An arrangement for the noninvasive coupling of information from a plurality of devices, including sensors, to an optical fiber at different locations uses a photodetector and a fiber bender attached to each device in such a manner that the sequential transmission of trigger signals to the photodetector of each device causes the sequential coupling of the information to the optical fiber by the fiber bender.

Abstract: In the fiber optic refrigerator of this invention the absorption of a photon of a preselected energy causes the emission of a luminescence photon of energy higher than that of the absorbed photon. This process requires the extraction of thermal energy from the fiber optic refrigerator, thus causing the cooling of any object or environment in thermal communication with the refrigerator.

Abstract: Methods and devices for medical treatment of biological tissue use fiber optic tips attached to the end of an optical fiber light guide for thermal treatment or photo-irradiation of said tissue, said tip including a photoluminescent material capable of acting as the tip's temperature probe. The photoluminescent material allows the tip to act as a controlled temperature surgical device or as a simple, efficient and easy to fabricate laser light diffuser.

Abstract: Optical temperature sensors use a temperature-dependent relative distribution of the intensity of interrogating light of wavelengths .lambda..sub.1 between two light-guiding regions of a light-guiding probe. The relative distribution can be determined by a plurality of means including the spatial separation of the lights carried by the two light-guiding regions, and/or the conversion of one of the lights into light of wavelengths .lambda..sub.2 different and easily separable from light of wavelength .lambda..sub.1. The sensors can be adapted to measure infrared radiation by measuring its heating effect on the sensing probes and to convert a thermal infrared image into a visible image.

Abstract: The method subject of the invention is based on fiber optic technology, and in particular on the light transmission changes at a wavelength or wavelengths .lambda..sub.s within an optical absorption band of hemoglobin occurring over a length of bare core of an optical fiber, inserted in an artery and covered with the patient's blood, when a clear aqueous saline or dextrose solution, optically transparent at said wavelength or wavelengths .lambda..sub.s, displaces much of the blood as it flows around the fiber core under the heart's pumping action.

Abstract: The invention relates to fiber optic methods and devices for sensing physical parameters, like temperature or force, by converting a fraction of the intensity of the interrogating light into a positive signal with wavelengths and/or light propagation modes different from those of the interrogating light. Preferred embodiments make use of the redistribution of the intensity of the interrogating light between the core and a secong light-guiding region of an optical fiber probe, and the processing of the light carried by said second light-guiding region into a positive signal separable from the interrogating light.

Abstract: Optical temperature sensors use a temperature-dependent relative distribution of the intensity of interrogating light between two light-guiding regions of a light-guiding probe. The relative distribution can be determined by a plurality of means including the spatial separation of the lights carried by the two light-guiding regions, and/or the conversion of one of the lights into light of wavelengths different easily separable from the wavelength or wavelengths of the interrogating light. The sensors can be adapted to measure infrared radiation by measuring its heating effect on the sensing probes to convert a thermal infrared image into a visible image.

Abstract: Methods and devices for sensing temperature changes at a plurality of locations use a light-transmitting optical fiber system along a path including said locations, said optical fiber system having a first end and a second end and a sensing element of said locations, each sensing element being so characterized that, when exposed to the temperature changes to be sensed and transmitting interrogating light of suitable wavelength or wavelengths .lambda..sub.v and an intensity P.sub.o, it converts a fraction .alpha.P.sub.o of the intensity of said interrogating light into a light separable from the interrogating light, at least part of the intensity of which is emitted from at least one of said two ends of the probe at wavelengths .lambda..sub.f different from .lambda..sub.v, where .alpha. is a temperature-dependent fraction smaller than unity, the value of which increases with increasing temperature within a temperature range, the intensity of said light of wavelengths .lambda..sub.

Abstract: A fiber optical source of stimulated optical radiation comprises an optical fiber which includes a core doped with laser material having optical gain in two wavelength regions, the fiber additionally including a material in optical communication with said laser material in such a manner as to absorb radiation emitted from said laser material within one of said wavelength regions.

Abstract: The invention is drawn to a planar luminescent solar concentrator including an optical fiber comprised of laser material. Solar energy collected by the concentrator is processed into laser radiation emitted by the optical fiber with high energy density corresponding to a concentration factor much greater than possible with prior art luminescent solar concentrators.

Abstract: The invention relates to methods and devices for measuring physical parameters by converting a fraction of the intensity of the interrogating light into a positive optical signal with wavelengths and/or light propagation modes different from those of the interrogating light, and having at least one characteristic which is a known function of the physical parameter being measured. The invention is adapted to the measurement of distributed forces and/or temperatures along a continuous length of optical fiber, and to the non-invasive coupling of information into an optical fiber from the side at any point or a multiplicity of points. The optical fiber is so designed that information signals coupled into it simultaneously at different points are separable at one end of the fiber and measurable without interference from each other.

Abstract: The invention is drawn to methods and devices for measuring temperature with a simple probe, a single interrogating light source and a single photodetector in a manner that the same probe can be used for simultaneously sensing another physical parameter, using the same interrogating light source and the same photodetector. The invention also allows the use of a single probe for measuring temperature in two independent physical modes, using a single interrogating light source and a single photodetector. In a preferred embodiment the probe includes a photoluminescent material having a luminescence decay time which decreases substantially with increasing temperature over a temperature range within which its luminescence quantum efficiency remains approximately constant or varies only minimally.

Abstract: Optical sensors for physical parameters use a parameter-dependent relative distribution of the intensity of interrogating light of wavelengths .lambda..sub.1 between two light-guiding regions of a light-guiding probe. The relative distribution can be determined by a plurality of means including the spatial separation of the lights carried by the two light-guiding regions, and/or the conversion of one of the lights into light of wavelengths .lambda..sub.2 different and easily separable from light of wavelength .lambda..sub.1. The sensors can be adapted to measure diverse physical parameters, including but not limited to temperature, and to measure infrared radiation by measuring its heating effect on the sensing probes.

Abstract: The invention is drawn to methods and devices for measuring temperature with a simple probe, a single interrogating light source and a single photodetector in a manner that the same probe can be used for simultaneously sensing another physical parameter, using the same interrogating light source and the same photodetector. The invention also allows the use of a single probe for measuring temperature in two independent physical modes, using a single interrogating light source and a single photodetector. In a preferred embodiment the probe includes a photoluminescent material having a luminescence decay time which decreases substantially with increasing temperature over a temperature range within which its luminescence quantum efficiency remains approximately constant or varies only minimally.

Abstract: The invention relates to methods and devices for measuring physical parameters by converting a fraction of the intensity of the interrogating light into a positive optical signal with wavelengths and/or light propagation modes different from those of the interrogating light, and having at least one characteristic which is a known function of the physical parameter being measured. The invention is adapted to the measurement of distributed forces and/or temperatures along a continuous length of optical fiber, and to the non-invasive coupling of information into an optical fiber from the side at any point or a multiplicity of points. The optical fiber is so designed that information signals coupled into it simultaneously at different points are separable at one end of the fiber and measurable without interference from each other.

Abstract: The invention is drawn to methods and devices which allow the simultaneous optical measurement of temperature and another physical parameter using a single probe, a single interrogating light source and a single photodetector. The invention also allows the use of a single probe for meausring temperature in two independent physical modes, using a single interrogating light source and a single photodetector. The single probe includes a photoluminescent material having luminescent centers which when excited with transient interrogating light of a wavelength within a predetermined spectral range emit luminescence light from two excited electronic energy levels, one of them being higher than the other and having a higher rate of luminescence decay than the other level, and wherein the relative intensities of the luminescence light emitted from each of the two excited energy levels vary as a function of the probe temperature.