Abstract: A temperature sensor that has an elongated sensing element having a length of at least 10 m, measured at a temperature of 20° C. The elongated sensing element includes an elongated jacket and an optical fiber mounted in the jacket and having an EFL of at least 0.35%, wherein the elongated sensing element has an average temperature error of less than 2° C.

Abstract: A composite photonic crystal comprising an inverse opal structure defining an ordered array of voids with a filler composition received within the voids. A property of the filler composition changes in response to a stimulus, such as a temperature change, thereby changing the band gap of radiation that is reflected by the composite photonic crystal.

Abstract: The invention relates to a method and a sensor for determining the hydrocarbon dew point in a gas, in particular in a gaseous fuel. According to the invention a roughened condensation surface is provided on a planar measurement surface of a transparent body. Light is shone onto the roughened condensation surface through the transparent body and the intensity of the light reflected back into the transparent body is measured. The hydrocarbon dew point temperature can be inferred from changes in the intensity of the light which is reflected back when heating or cooling the condensation surface.

Abstract: A coating material (20) for coating a machine component (10), especially a gas turbine or a part thereof, comprises a mixture of at least a refractory material and an indicator material having an optical emission (e.g. fluorescence) spectrum which varies in response to a physical parameter of the coated component. In a preferred embodiment, the coating consists of yttrium aluminum garnet (YAG) or yttrium stabilized zirconium. The dopant is preferably a rare earth metal, e.g. Eu, Tb, Dy.

Abstract: A method for monitoring a status of a sleeve for lining a system of pipes or conduits, the sleeve being impregnated with a curable resin, includes the steps of providing the sleeve, disposing at least one fiber optic sensor in thermally conductive contact with the sleeve, and generating, using the at least one fiber optic sensor, a positionally resolved thermographic image representative of a temperature of the sleeve as a function of position and time

Abstract: A method of measuring a temperature of a noble gas in a chamber includes providing the noble gas in the chamber. The noble gas is characterized by a pressure and a temperature. The method also includes directing a first laser beam into the chamber and directing a second laser beam into the chamber. The first laser beam is characterized by a first frequency and the second laser beam is characterized by a second frequency. The method further includes converting at least a portion of the first laser beam and the second laser beam into a coherent anti-Stokes beam, measuring a Doppler broadening of the coherent anti-Stokes beam, and computing the temperature using the Doppler broadening.

Abstract: To provide a temperature sensor probe that can take stable measurements, and a manufacturing method thereof. The temperature sensor probe related to the present invention is a temperature sensor probe for measuring temperature using a fluorescent substance that changes fluorescent characteristics depending on temperature. Then, a powdered fluorescent substance, a guide wave route member that propagates excitation light, which is irradiated on the fluorescent substance, and fluorescent light, which is produced by the fluorescent substance, are provided. Further, the particle size of the powdered fluorescent substance is confined to the range of 60 to 100 ?m.

Abstract: Methods and apparatus for wafer temperature measurement and calibration of temperature measurement devices may be based on determining the absorption of a layer in a semiconductor wafer. The absorption may be determined by directing light towards the wafer and measuring light reflected from the wafer from below the surface upon which the incident light impinges. Calibration wafers and measurement systems may be arranged and configured so that light reflected at predetermined angles to the wafer surface is measured and other light is not. Measurements may also be based on evaluating the degree of contrast in an image of a pattern in or on the wafer. Other measurements may utilize a determination of an optical path length within the wafer alongside a temperature determination based on reflected or transmitted light.

Abstract: A temperature sensor is disclosed. The sensor includes an optical fiber and at least one twin-grating structure formed on the optical fiber. Each twin-grating structure includes a first optical grating structure, a second optical grating structure adjacent the first optical grating structure, and a sensing cavity disposed between the first and second optical grating structures. Each twin-grating structure is selectively responsive to a unique wavelength of light to generate an optical interference fringe signal. For each twin-grating structure, an optical property of the twin-grating structure and a phase of the optical interference fringe signal generated by the twin-grating structure are determined by a temperature of the twin-grating structure.

Abstract: An optical fiber temperature sensor comprising: an optical pulse generator; an optical fiber into which said optical pulses are fed; an optical receiver to receive said optical pulses reflected by said optical fiber and to convert them into an electrical signal; a processor which receives said electrical signal and determines the temperature along said optical fiber; said optical receiver comprising a first filter and a second filter to filter said optical pulse reflected by said optical fiber, characterized in that said first and said second filters filter two adjacent portions of anti-Stokes optical signals or of Stokes optical signals.

Abstract: The invention relates to a method for integrating an optical waveguide (3) of a temperature sensor and/or strain sensor into a temperature and/or strain measuring component (1) made of a base material (2), onto which a coating (5) is applied. The optical waveguide (3) is arranged on a predetermined measurement plane, whereupon a coating (5) is applied. The aim of the invention is to allow an optical waveguide (3) to be accurately integrated into and tightly joined to the body of a temperature and/or strain measuring component (1).

Abstract: A freeze indicator can include an indicator dispersion having an aqueous liquid medium and organic material indicator particles dispersed in the aqueous liquid medium. The indicator dispersion can have an initial appearance before freezing and an irreversibly different appearance after freezing and can exhibit a freeze-onset temperature of about ?1.9° C. or higher. Some factors helpful to providing a relatively high freeze onset temperature are employment of a proteinaceous ice-nucleating agent, control of pH, use of a protein stabilizer and control of the ratio of protein stabilizer to ice-nucleating agent.

Abstract: To provide a temperature sensor probe that can conduct stable measurements, and the manufacturing method of the same. The temperature sensor probe related to the present invention provides: a fluorescent material that is a mixture of a fluorescent substance and a transparent material; a thermosensitive part having a concave part in which the fluorescent material is arranged; a waveguide route rod that propagates excitation light, which is irradiated on the fluorescent material, and fluorescent light, which is produced by the fluorescent substance; and a protective tube that covers the side surfaces of the waveguide route rod. Then, the fluorescent material is affixed to the tip of the waveguide route rod using the transparent material, and the waveguide route rod bites into the fluorescent material.

Abstract: The polarization-maintaining fiber of the invention includes a core (1) made of germanium doped silica glass; a stress-applying part (3) made of boron doped silica glass; a cladding (2) made of pure silica glass; and a polyimide coating layer (4) with a thickness of 10 ?m or less that surrounds the outer periphery of the cladding (2).

Abstract: A method for calculating a temperature along a length of a sensing fiber of a distributed thermal sensing (DTS) system. The sensing fiber, which has two ends, is heat resistant for operation up to 300° C. The DTS system includes a two-channel DTS interrogator that is attached to each of the two ends of the sensing fiber. The DTS interrogator interrogates the sensing fiber from both ends, calculates a temperature difference between co-located positions along the length of the sensing fiber for each end, and determines an error associated with the temperature difference. Based on the determined error, a corrected temperature value along the length of the sensing fiber is calculated and outputted.

Abstract: For a temperature measurement in areas having electromagnetic fields, shielding devices must be provided. According to the proposed technique, at least one temperature sensor is designed as a fiber-optic sensor having Bragg gratings (FBG), wherein the sensor is arranged in a non-metallic housing that precludes or minimizes expansion effects for the individual FBG sensors. For example, the proposed technique can be used advantageously to measure the temperature distribution in oil sand deposits, for which purpose a suitable measuring arrangement is required.

Abstract: A sensing cable has a sensing fiber assembly, which includes a pair of sensing fibers joined by a turnaround section with a modal filter, at a terminating end of the sensing fibers. The sensing cable also includes an inner sleeve that surrounds the sensing fiber assembly and an armored casing that caps the terminating end of the inner sleeve. The sensing cable has a low profile and its components are each made of high temperature and hydrogen tolerant materials and are capable of prolonged operation at high temperatures, such as up to 300° C., in hydrogen environments over long lengths of fiber. A distributed thermal sensing (DTS) interrogator is connected to the sensing cable and performs DTS measuring according to protocols and algorithms that leverage the modal filter of the turnaround section to calculate temperature readings along the sensing fiber assembly.

Abstract: A multi-mode optical waveguide fiber including a central core region having an outer radius surrounded by an inner cladding region having an outer radius, the inner cladding region having a lower index of refraction than the central core region, wherein both the central core and inner cladding regions are doped with fluorine, wherein the refractive index profile of the central core region is of the gradient index type and the central core region in the range of r?[0-ra] comprises germanium at a maximum concentration within the range of 0.5 percent by weight to 4.0 percent by weight taken at a given radius, wherein said fiber has an Overfilled Modal Bandwidth >500 MHz·km at a wavelength of 850 nm and 1300 nm, according to IEC 60793-2-10.

Abstract: The present invention relates to an optical temperature sensor, comprising: a housing; a light-transmitting unit, installed in the housing, for emitting light transmitted through an optical fiber into an inner space of the housing; and a bimetal device, movably installed in the housing, for varying the amount of transmitted light, wherein the optical temperature sensor is capable of measuring a temperature by using the amount of light, from the light transmitted via the optical fiber, which is shielded through bending due to a change in the temperature of the bimetal device, or using the amount of light, from the transmitted light, which is reflected and received. The optical temperature sensor has a simple structure and is not particularly restricted in terms of installation space.

Abstract: A temperature measurement system includes: a laser light source; an optical fiber; and a temperature measurement unit configured to acquire a measured temperature distribution of a temperature of a temperature measurement area along an installation path of the optical fiber by detecting backscattered light of the incident laser light in the optical fiber, wherein the temperature measurement unit sequentially makes a correction for the measured temperature distribution a plurality of times so as to make a square error between a convolution of a transfer function of the optical fiber along the installation path and the corrected temperature distribution and the measured temperature distribution smaller in each of the corrections, and the temperature measurement unit also replaces a corrected temperature at a specific point of the installation path with an estimated temperature at the specific point in each of the corrections.

Abstract: The present invention is directed to passive thermal monitoring devices, and methods of making and using the passive thermal monitoring devices.

Abstract: Silicon Carbide (SiC) probe designs for extreme temperature and pressure sensing uses a single crystal SiC optical chip encased in a sintered SiC material probe. The SiC chip may be protected for high temperature only use or exposed for both temperature and pressure sensing. Hybrid signal processing techniques allow fault-tolerant extreme temperature sensing. Wavelength peak-to-peak (or null-to-null) collective spectrum spread measurement to detect wavelength peak/null shift measurement forms a coarse-fine temperature measurement using broadband spectrum monitoring. The SiC probe frontend acts as a stable emissivity Black-body radiator and monitoring the shift in radiation spectrum enables a pyrometer. This application combines all-SiC pyrometry with thick SiC etalon laser interferometry within a free-spectral range to form a coarse-fine temperature measurement sensor.

Abstract: A method and apparatus is provided for determining when a battery, or one or more batteries within a battery pack, undergoes an undesired thermal event such as thermal runaway. The system uses an optical fiber mounted in close proximity to, or in contact with, an external surface of the battery or batteries to be monitored. A source of light is optically coupled to the input facet of the optical fiber and a detector optically coupled to the output facet of the optical fiber. Battery health is determined by monitoring the light transmitted through the optical fiber.

Abstract: There is provided an optical fiber temperature distribution measuring device which measures a temperature distribution along an optical fiber (3) using backward Raman scattering light generated in the optical fiber. The device includes: a reference temperature thermometer (11) disposed in the vicinity of the optical fiber so as to measure a reference temperature (T1, T2) of the optical fiber; an arithmetic controller (7) that calculates a temperature (T) of the optical fiber based on the backward Raman scattering light; and a temperature corrector (12) that corrects the calculated temperature (T) based on a correction formula containing the reference temperature as a parameter.

Abstract: A temperature monitoring system for a medical device comprises an optical transmit/receive unit, an elongate optical fiber having a proximal end, a distal end, and an inner core extending between the proximal end and the distal end, and one or more fiber Bragg grating elements formed in the inner core of the optical fiber. The optical fiber is operably coupled to the transmit/receive unit at the proximal end. At least a portion of the optical fiber is also operably coupled to a medical device and is structured to measure temperature at one or more temperature sensing locations on the medical device.

Abstract: This invention teaches the fiber optic sensors temperature sensors for cryogenic temperature range with improved sensitivity and resolution, and method of making said sensors. In more detail, the present invention is related to enhancement of temperature sensitivity of fiber optic temperature sensors at cryogenic temperatures by utilizing nanomaterials with a thermal expansion coefficient that is smaller than the thermal expansion coefficient of the optical fiber but larger in absolute value than the thermal expansion coefficient of the optical fiber at least over a range of temperatures.

Abstract: A probe for temperature measurement uses interference of a low-coherence light beam. The probe includes a temperature acquiring member configured to be brought into contact with a surface of a temperature measurement target and thermally assimilate with the temperature measurement target; a light irradiating/receiving unit configured to irradiate a measurement light beam as a low-coherence light beam to the temperature acquiring member and receive reflected light beams from a front surface and a rear surface of the temperature acquiring member; and a housing configured to define a distance between the temperature acquiring member and the light irradiating/receiving unit to a preset length and isolate optical paths of the measurement light beam and the two reflected light beams from an atmosphere in which the temperature measurement target is placed.

Abstract: The present invention provides a dual-probe thermally compensated fluorescence decay rate temperature sensor capable of measuring the true temperature of a sample surface and its associated method of use.

Abstract: A mount (20) for a temperature-compensated fibre optic strain gauge (10), the mount (20) comprising: a void (19) located at a middle portion of the mount (20) to separate the mount (20) into a first section (17) and a second section (18); and removable bridges (24) to connect the first section (17) to the second section (18); wherein after the mount (20) has been operatively attached to a host structure (5), the removable bridges (24) are removed.

Abstract: The temperature of an object such as a semiconductor wafer that includes silicon can be determined based on the variation of the optical absorption coefficient of silicon with temperature. Temperatures above about 850° C., can be found by measuring phenomena that are affected by the magnitude of the optical absorption coefficient, especially at wavelengths >˜1 ?m. Phenomena could include measuring light reflected, transmitted, emitted, absorbed, or scattered by the wafer and deriving the absorption coefficient from the measurements and then deriving temperature from the absorption coefficient. Temperature could be determined from a model relating phenomena directly to temperature, the model constructed based on absorption behavior and techniques discussed herein. The resulting temperature could be used to calibrate or control a rapid thermal processing chamber or other apparatus.

Abstract: The invention relates generally to a non-intrusive method for sensing gas temperature and species concentration in gaseous environments. The method includes the steps of providing a tunable diode laser (TDL) sensor having a plurality of robust telecommunications diode lasers and a detector. The method further includes the steps of positioning the TDL sensor in alignment with an optical port of a vessel; using the lasers to transmit light through the optical port; using the detector to receive the transmitted light and transmit a signal to a data collection device; determining a ratio of absorbance for different absorption transitions; and determining a gas temperature from the ratio of absorbance.

Abstract: Various embodiments of thermal sensing systems and methods for monitoring thermal conditions in such material processing assemblies are described. The thermal sensing systems include a sensor cable that incorporates or is coupled to one or more thermal sensors. The sensor cable is positioned in the assembly and the thermal sensors provide temperature measurements. In various embodiments, the sensor cable and thermal sensors may be optical or electrical devices.

Abstract: An optical fiber with long period fiber gratings includes an optical fiber axis, a core region extending along the fiber axis, the core region having a core refractive index, a cladding region surrounding the core region, the cladding having a cladding refractive index, and a plurality of microholes perpendicular to the fiber axis with a portion of the core region removed, the plurality of microholes are spaced apart by a grating period.

Abstract: An optical fiber temperature sensor includes an optical transceiver module, a transmission fiber and a sensing head. When the transmission fiber is a polarization maintaining fiber, the sensing head includes a temperature sensing element and a fiber reflector, the temperature sensing element is a section of polarization maintaining fiber. The transmission fiber is fusion spliced with the temperature sensing element, an angle between a polarization axis of the transmission fiber and that of the temperature sensing element is 45 degree at the fusion splicing point. When the transmission fiber is a single-mode fiber, the sensing head includes a polarizer. An angle between a polarization axis of the polarization maintaining fiber connecting the temperature sensing element with the polarizer and that of the polarization maintaining fiber of the temperature sensing element is 45 degree at the fusion splicing point. The present invention is of simple principle and structure, and facilitates manufacturing.

Abstract: An optical device and method is disclosed for forming the optical device within the wide-bandgap semiconductor substrate. The optical device is formed by directing a thermal energy beam onto a selected portion of the wide-bandgap semiconductor substrate for changing an optical property of the selected portion to form the optical device in the wide-bandgap semiconductor substrate. The thermal energy beam defines the optical and physical properties of the optical device. The optical device may take the form of an electro-optical device with the addition of electrodes located on the wide-bandgap semiconductor substrate in proximity to the optical device for changing the optical property of the optical device upon a change of a voltage applied to the optional electrodes. The invention is also incorporated into a method of using the optical device for remotely sensing temperature, pressure and/or chemical composition.

Abstract: A single fiber Mach-Zehnder interferometer comprises an optical fiber having a core region and a cladding surrounding the core region, and a micro-cavity having part of the cladding and the core region removed, wherein the micro-cavity is adapted to receive a light beam and separate the light beam into a first light beam that propagates through the micro-cavity in an unguided mode, and a second light beam that propagates through the core region in a guided mode.

Abstract: Apparatus for a spatially resolved temperature measurement, with at least one optical fiber (6) for the spatially resolved temperature measurement, and at least one laser light source (2) producing light (3, 23) which can be coupled into the optical fiber (6), wherein the portions of the light (3, 23) backscattered in the optical fiber (6) can be coupled out of the optical fiber (6) and evaluated. The apparatus further includes means for reducing polarization-induced effects, wherein the means may be, for example, a polarization modifier (4) capable of at least partially depolarizing the light (3).

Abstract: A distributed optical fiber sensor system is provided. In this system, backward-scattered light generated in a test optical fiber is filtered to separate the backward-scattered light into Raman scattered light and Brillouin scattered light. The separated Raman scattered light and Brillouin scattered light are each converted into digital data. A change in temperature with respect to the distance of the test optical fiber is measured from the digital data of the Raman scattered light. A change in temperature and a change in the degree of deformation with respect to the distance of the test optical fiber are measured from the digital data of the Brillouin scattered light. The change in temperature and the change in the degree of deformation with respect to the distance of the test optical fiber are separately output using the measured data.

Abstract: An improved laser source for use in a distributed temperature sensing (DTS) system (and DTS systems employing the same) includes a laser device and drive circuitry that cooperate to emit an optical pulse train at a characteristic wavelength between 1050 nm and 1090 nm. An optical amplifier, which is operably coupled to the laser device, is adapted to amplify the optical pulse train for output over the optical fiber sensor of the DTS system. In the preferred embodiment, the laser device operates at 1064 nm and outputs the optical pulse train via an optical fiber pigtail that is integral to its housing. The optical power of the optical pulse train generated by the laser source is greater than 100 mW, and preferably greater than 1 W, at a preferred pulse repetition frequency range between 1 and 50 kHz, and at a preferred pulse width range between 2 and 100 ns.

Abstract: An optical fiber temperature distribution measuring apparatus and a method for measuring optical fiber temperature distribution, provided with a light source for inputting a pulse light to an optical fiber to be measured, a signal detecting unit for detecting a received light intensity of a predetermined light included in a backscattering light generated by an input of the pulse light in the optical fiber to be measured, and a signal processing unit for calculating a value corresponding to a variation of the received light intensity due to a hydrogen molecular absorption of the optical fiber to be measured based on the received light intensity of the predetermined light, to compensate the received light intensity of the predetermined light corresponding to a temperature of the optical fiber to be measured based on the value.

Abstract: Embodiments of the invention relates to a temperature sensor and an analytical device comprising the same. The temperature sensor comprises a carrier (11) with a detection surface (12) on which temperature indicating agents (14) are present and, optionally, at which target components can collect and optionally bind to specific capture elements. An incident light beam (L1) is transmitted into the carrier and evanescent wave excitation is induced at the detection surface (12). The amount of light in the reflected light beam (L2) or an optical, e.g. luminescence response is then detected by a light detector (31). In one example, evanescent light is affected (absorbed, scattered) by temperature indicating agents and optionally target components and/or label particles at the binding surface (12) and will therefore be missing in a frustrated total internal reflected light beam (L2).

Abstract: A temperature measuring arrangement measures the temperature of a fluid passing a component. The arrangement includes a temperature measuring device having a substrate of low thermal capacity that has applied thereto two or more temperature recording media. The device is attached to and spaced apart from the component and is in the fluid flow.

Abstract: Disclosed is an electrostatic chuck with a temperature sensing unit, exposure equipment having the electrostatic chuck, and a method of detecting temperature on photomask surfaces. The temperature sensing unit and method of detecting temperature may include obtaining reflectance of a photomask using a multi-wavelength interferometer and determining a temperature on the photomask based on the reflectance.

Abstract: An x-ray tube disclosed here in includes an emitter arranged to emit electrons on to a focal spot on a rotatable anode. The x-ray tube also includes a hollow tube arranged to receive electromagnetic radiation from the focal spot at one end of the hollow tube and transmit it to another end. The x-ray tube also includes two or more sensors arranged to detect the electromagnetic radiation through the hollow tube.

Abstract: A method and system for calibrating temperature measurement devices, such as pyrometers, in thermal processing chambers are disclosed. According to the present invention, the system includes a calibrating light source that emits light energy onto a substrate contained in the thermal processing chamber. A light detector then detects the amount of light that is being transmitted through the substrate. The amount of detected light energy is then used to calibrate a temperature measurement device that is used in the system.

Abstract: The present invention provides a dual-probe thermally compensated fluorescence decay rate temperature sensor capable of measuring the true temperature of a sample surface and its associated method of use.

Abstract: An optical fibre temperature sensor comprising: an optical pulse generator; an optical fibre into which said optical pulses are fed; an optical receiver to receive said optical pulses reflected by said optical fibre and to convert them into an electrical signal; a processor which receives said electrical signal and determines the temperature along said optical fibre; said optical receiver comprising a first filter and a second filter to filter said optical pulse reflected by said optical fibre, characterised in that said first and said second filters filter two adjacent portions of anti-Stokes optical signals or of Stokes optical signals

Abstract: A method of coupling a silica fiber and a sapphire fiber includes providing a silica fiber having a doped core and a cladding layer, with the doped core having a prescribed diameter, providing a sapphire fiber having a diameter less than the doped core, placing an end of the sapphire fiber in close proximity to an end of the silica fiber, applying a heat source to the end of silica fiber and introducing the end of sapphire fiber into the heated doped core of the silica fiber to produce a coupling between the silica and sapphire fibers.

Abstract: The present invention provides an optical sensor for monitoring current or power in a monitored element of a device such as a bridge-wire or hot-wire of electro-explosive devices. The optical sensor comprises an optical sensor made of semiconductor material. The semiconductor material comprises an absorption edge which is sensitive to a temperature variation. The semiconductor material is for placing in thermal contact with the monitored element of the device, whereby, when the current or power varies in the monitored element, it causes a variation in temperature in the semiconductor element and hence a spectral shift of the absorption edge which can be measured and which is representative of current and power variation.

Abstract: The invention relates to a method for controlling flat glass forming by flowing a molten glass over a liquid tin layer contained in a forming vat wherein a forming characteristic quantity is measured above the glass surface during forming by means of beams generated by at least one absorption spectroscopy-based analyser, wherein the light beams generated by said analyser form a net above the glass surface. A device for carrying out the inventive method comprising an arm for supporting a vessel which comprises a retroreflecting means for receiving a light beam and transmitting it in an opposite direction parallel to an incident optical path is also disclosed.