Abstract: A miniaturized fiber Bragg grating (FBG) interrogation system may comprise a light source, a FBG sensor, and a photodetector. The FBG sensor may be configured to receive an optical signal from the light source, interact with a transmitted spectrum of the light source over a discriminating spectral domain, and generate a reflected optical signal representative of a change in a physical signal sensed by the FBG sensor. Additionally, the system may include a power management unit configured to reduce power consumption in order to prolong the lifespan of the system.

Abstract: An infrared heating device that appropriately sets positions of infrared lamps and a radiation thermometer relative to an object to be heated and is easily positioned includes: an infrared irradiator that irradiates infrared rays to an object to be heated to heat the object to be heated; a holding member that holds the infrared irradiator; a radiation thermometer that measures a temperature of a surface of the object; and a pair of laser pointers that irradiate laser beams to the surface of the object from different positions. The pair of laser pointers are disposed to cause the respective laser beams to be coincident in position with each other at one point on the surface of the object when a distance between the surface of the object and the infrared irradiator is a predetermined distance.

Abstract: An aircraft pressure measurement device includes a pressure sensor, a pressure measurement path, a valve, and a fluid port. The pressure measurement path extends between an aircraft skin and the pressure sensor, and the valve is positioned within the pressure measurement path between the aircraft skin and the pressure sensor. The valve is configured to regulate airflow through the pressure measurement path, and the fluid port is configured to allow a pressurized fluid into the pressure measurement path to clear the pressure measurement path of debris. The improved pressure measurement device allows the aircraft to automatically clear debris from the pressure measurement path both during flight and while on the ground, removing the need for manual cleaning processes.

Abstract: A diagnostic field device for identifying a diagnostic condition in an industrial process includes an infrared sensor array having a plurality of infrared sensors arranged to sense infrared emissions from a location in the industrial process. Processing circuitry processes outputs from the plurality of infrared sensors of the sensor array and generates an infrared image. Diagnostic circuitry compares processed outputs from at least two subsections of the infrared image and provides a diagnostic output based upon the comparison.

Abstract: Reduces an increase in temperature of the blade member. Comprises: a blade supporting member, disposed forward of a photodetecting sensor that acts as a thermal source, having an opening 1a through which passes light that is to be incident into the photodetecting sensor; a blade member, supported movably on the blade supporting member, for opening and closing the opening; an actuator for driving the blade member open and closed, wherein: wherein the blade supporting member comprises a containing portion 1b, for containing the blade member and the actuator on a front or rear surface that is perpendicular to the optical axis of the opening, and an exposed portion that is arranged in parallel to the containing portion.

Abstract: A gas turbine engine includes a core engine having a casing, a cowl disposed annularly around the casing such that a gap is formed between the casing and the cowl, and a thermal monitoring system having at least one camera positioned within the gap, wherein the at least one camera is configured to detect thermal radiation from at least one turbine component within the gap.

Abstract: An infrared microscope includes a radiation source, a sample plane, an objective lens, a path length modulator and a detector. The radiation source emits temporally coherent infrared radiation that propagates along an optical path of the microscope during operation. A sample is disposed in the sample plane. The detector detects the infrared radiation after the radiation interacts with the sample. The objective lens forms an image of the sample plane on the detector. The path length modulator continuously varies the optical path length of the optical path between the sample plane and the detector. The path length modulator can be a wedge or a diffusing screen that rotates during operation, a phase modulator that rotates during operation and that has regions with different indices of refraction, a tilting element that tilts about an axis during operation, or a diffuser mirror that reflects the infrared radiation and that rotates during operation.

Abstract: A low profile un-lensed non-intrusive stress measurement system probe may comprise a housing comprising a first channel and an optical face, a first hypotube disposed within the first channel and coupled at a sensing aperture in the optical face, and a plurality of optical fibers disposed within the first hypotube, wherein the first hypotube executes a bend between 45° and 90° within the housing.

Abstract: An improved system and method of measuring the temperature of a workpiece being processed is disclosed. The temperature measurement system determines a temperature of a workpiece by measuring the amount of expansion in the workpiece due to thermal expansion. The amount of expansion may be measured using a number of different techniques. In certain embodiments, a light source and a light sensor are disposed on opposite sides of the workpiece. The total intensity of the signal received by the light sensor may be indicative of the dimension of the workpiece. In another embodiment, an optical micrometer may be used. In another embodiment, a light sensor may be used in conjunction with a separate device that measures the position of the workpiece.

Abstract: Apparatus and methods are described for monitoring a female subject. A sensor is configured to monitor the subject without contacting the subject or clothes the subject is wearing, and without viewing the subject or clothes the subject is wearing, and to generate a sensor signal in response to the monitoring. A computer processor is configured to receive the sensor signal, and to analyze the sensor signal. In response to the analyzing, the computer processor is configured to automatically identify a menstrual state of the subject, and to generate an output in response thereto. Other applications are also described.

Abstract: A device provides a temperature control and/or monitoring, including a controller to receive a minimum temperature value and a maximum temperature value of a temperature range to be measured. The controller correlates a known output signal range of a temperature sensor to the temperature range to be measured. Further, the controller receives an output signal from the temperature sensor, and generates a measured temperature value based on the output signal of the temperature sensor. A method to control and/or monitor a temperature is also provided.

Abstract: An apparatus for insertion through an opening in an outer casing of a gas turbine engine and inspection of internal turbine components at elevated temperatures having an optical sight tube configured to optically communicate with an interior of gas turbine engine via a distal end disposed at the interior and a proximal end disposed exterior of the internal turbine components and defined by a first longitudinal wall, at least one lens at the distal end of the optical sight tube adjacent to the longitudinal wall; and at least one longitudinal cooling groove in the longitudinal wall for flowing a cooling medium from a location external to the turbine to cool the optical sight tube at a location at least adjacent the distal end.

Abstract: The disclosure relates to an optical characteristic measurement system including at least: a light source unit which outputs an input beam of a specific wavelength; a sensing unit which generates a signal beam by using a sensor whose optical characteristic is affected by an external environment condition; and a measuring unit which derives varied physical amount by using the signal beam delivered from the sensing unit, wherein the measuring unit includes: an optical coupler which distributes the signal beam into the two optical paths; and an interrogation optical fiber which is arranged on one of the paths on which the signal beam travels. The interrogation optical fiber has a linear light absorption characteristic in the specific wavelength range, and the light intensity of the signal beam is measured to detect a wavelength of the signal beam delivered from the sensing unit, and finally derive the physical amount applied from outside.

Abstract: A concentration correction system includes an infrared detector and components that produce an aggregate emission of infrared radiation. A mirror assembly includes a mirror and is changeable between a correcting configuration and a measuring configuration. In the correcting configuration, the mirror produces a mirror signal incident on the detector. The mirror assembly also obstructs external body infrared radiation from reaching the detector. In the measuring configuration, the mirror assembly allows the external body infrared radiation onto the detector. A concentration correction method includes receiving external body infrared radiation and simultaneously receiving a first portion of the aggregate emission. A measurement value indicative of concentration is recorded from the detector. A second portion of the aggregate emission reflected with the mirror and produces a mirror signal incident on the detector.

Abstract: An autonomous ventilation system includes a variable-speed exhaust fan, a controller, an exhaust hood, and an infrared radiation (“IR”) sensor. The exhaust fan removes air contaminants from an area. The controller is coupled to the exhaust fan and adjusts the speed of the exhaust fan. The exhaust hood is coupled to the exhaust fan and directs air contaminants to the exhaust fan. The IR sensor is coupled to the controller, detects changes in IR index in a zone below the exhaust hood, and communicates information relating to detected changes in IR index to the controller. The controller adjusts the speed of the exhaust fan in response to information relating to detected changes in IR index. The autonomous ventilation system also includes an alignment laser to indicate a point at which the IR sensor is aimed and a field-of-view (“FOV”) indicator to illuminate the zone in which the IR sensor detects changes in IR index.

Abstract: There are many industrial applications in which non-contact temperature sensing is useful for increasing production speed and quality, such as printing, laminating, extrusion, and metal forming. Disclosed is a non-contact temperature determining apparatus which uses two wide wavelength bands integrating sensors to determine the radiance ratio of a target and thereby determine a corresponding temperature of the target. Also disclosed is a non-contact temperature determining apparatus in which a beam splitter passes one wide wavelength band to a sensor and reflects another distinct wide wavelength band to another sensor from which temperature can be determined. A disclosed embodiment of the dual waveband temperature detector improves upon traditional and currently available ratio pyrometers by further reducing the cost of the system, making installation and use easier, and improving temperature detection for low temperature industrial applications.

Abstract: Optomechanical device for actuating and/or detecting movement of a mechanical element, in particular for gravimetric detection. It includes a support with a mechanical element anchored to the support which is designed to move relative to the element, and a device for actuating and/or detecting movement or of variations in frequency of movement of the element. A portion of the device is arranged beneath at least part of the element, between the element and the support. The device includes a fixed optical device with at least one optical waveguide arranged beneath all or part of the element at a determined distance from the element, and which is designed to propagate at least one optical wave having a given wavelength designed to interact with the element. The optical waveguide is at a determined distance from the mechanical element so that the evanescent field of the optical waveguide interacts with the mechanical element.

Abstract: A method for preparing a metal part pressurized under isentropic, shock-type or compression-type, uniaxial deformation conditions, so as to measure the temperature of same by optical pyrometry. The method includes forming an emissive coating on a face of the metal part, having a thickness of 250 to 550 nm, and fixing an anvil-shaped window on the emissive coating. The emissive coating includes a first and a second layer of amorphous carbon, the first layer being inserted between the face of the metal part and the second layer, and having a carbon hybridization rate sp3 greater than the carbon hybridization rate sp3 of the second layer. A method for measuring, by optical pyrometry, the temperature of a metal part pressurized under isentropic, shock-type or compression-type, uniaxial deformation conditions.

Abstract: Embodiments relate to characterizing underwater turbulence. Initially, multispectral laser light (MLL) is generated and then converted to output laser light (OLL). The OLL is received at a polarization rotator that causes the OLL to be emitted in one of multiple modes of polarization. Next, the OLL is directed toward a target medium, where the OLL causes backscattered light to be emitted from the target medium. While using the polarization rotator to switch between the multiple modes of polarization, Stokes parameters of the backscattered light are detected and then used to characterize the underwater turbulence of the target medium.

Abstract: A passive optical circuit breaker includes a substrate and an optical waveguide assembly arranged relative to the substrate. The optical waveguide assembly includes a first optical waveguide portion having a first low-loss portion and a first high-loss portion, and a second optical waveguide portion having a second low-loss portion. The first low-loss portion and the second low-loss portion define a first optical path through the optical waveguide assembly, and optical energy directed through the first high-loss portion exceeding a prescribed threshold causes the first optical waveguide portion to physically deflect relative to the second optical waveguide portion and interrupt the first optical path through the optical waveguide assembly.

Abstract: A method for estimating a temperature of a substrate includes generating plasma in a plasma processing system. The substrate is arranged on a substrate support structure in the plasma processing system. The plasma generates electromagnetic radiation that is incident upon a first surface of the substrate. The method further includes arranging a detector adjacent to a second surface of the substrate and in-situ the plasma processing system and measuring a signal intensity of electromagnetic radiation passing through the second surface of the substrate at N frequencies. The method includes selecting each of the N frequencies at which the signal intensity is measured by the detector to correspond to a phonon-generating frequency of a material in the substrate. The method includes converting the signal intensity at the N frequencies to N absorbance values and estimating a temperature of the substrate based on the N absorbance values.

Abstract: A method for measuring, from a thermal device, temperature, molecular number density, and/or pressure of a gaseous compound as function of distance, the gaseous compound absorbing at least some light. The method comprises generating, for a first wavelength band and a second wavelength band, a pulse sequence comprising a light pulse or light pulses, guiding the pulse sequence into the thermal device, and measuring, as function of time, the intensity of the scattered light at the first wavelength band and at the second wavelength band. The method further comprises determining information indicative of the differential absorption between the two wavelengths bands using measured intensities and determining the temperature, the molecular number density, and/or the pressure of the gaseous compound using the information indicative of the differential absorption between the two wavelengths bands. A thermal system arranged to carry out the method.

Abstract: In a device (1) for non-contact temperature measurement, it is proposed that an angle measuring device (5) is designed such that an emission angle (6) of the IR radiation detected with a detector (2) for temperature measurement can be measured on the measuring region (9) of a measuring object (3) emitting the IR radiation.

Abstract: An apparatus, method and associated fiber-laser architectures for high-power pulsed operation and pumping wavelength-conversion devices. Some embodiments generate blue laser light by frequency quadrupling infrared (IR) light from Tm-doped gain fiber using non-linear wavelength conversion. Some embodiments use a fiber MOPA configuration to amplify a seed signal from a semiconductor laser or ring fiber laser. Some embodiments use the frequency-quadrupled blue light for underwater communications, imaging, and/or object and anomaly detection. Some embodiments amplitude modulate the IR seed signal to encode communication data sent to or from a submarine once the modulated light has its wavelength quartered.

Abstract: A method for calculating power input to at least one thermal control element of an electrostatic chuck includes: setting the at least one thermal control element to a first predetermined power level; measuring a first temperature of the at least one thermal control element when the at least one thermal control element is powered at the first predetermined power level; setting the at least one thermal control element to a second predetermined power level; measuring a second temperature of the at least one thermal control element when the at least one thermal control element is powered at the second predetermined power level; calculating a difference between the first temperature and the second temperature; calculating a system response of the at least one thermal control element based on the difference; inverting the system response; and calibrating the at least one thermal control element based on the inverted system response.

Abstract: There are many industrial applications in which non-contact temperature sensing is useful for increasing production speed and quality, such as printing, laminating, extrusion, and metal forming. Disclosed is a non-contact temperature determining apparatus which uses two wide wavelength bands integrating sensors to determine the radiance ratio of a target and thereby determine a corresponding temperature of the target. Also disclosed is a non-contact temperature determining apparatus in which a beam splitter passes one wide wavelength band to a sensor and reflects another distinct wide wavelength band to another sensor from which temperature can be determined. A disclosed embodiment of the dual waveband temperature detector improves upon traditional and currently available ratio pyrometers by further reducing the cost of the system, making installation and use easier, and improving temperature detection for low temperature industrial applications.

Abstract: This invention relates to an internal combustion engine having a cavity for inspection, comprising: an inspection device mounted within a housing, the housing at least partially located within the cavity to be inspected and having a shutter which is actuable between a closed configuration and an open configuration; and an actuation mechanism for moving the shutter between the closed configuration and the open configuration.

Abstract: Methods for controlling substrate uniformity in a thermal processing chamber include a measuring process to provide temperature-related quantities across a radius of a substrate, correlating substrate properties with processing parameters to simulate deformation of the substrate at various radial distances over a temperature range, a thermal process so that temperature of at least one reference region within the substrate matches a target set point temperature, measuring a temperature of at least one reference region as the substrate rotates, measuring deformation of the substrate as the substrate rotates, correlating measured temperatures of at least one reference region with simulated deformation of the substrate and measured temperature-related quantities of the substrate to calculate a simulated shape change of the substrate over a temperature range, tuning substrate flatness by adjusting lamp temperature profile across the substrate based on simulated shape change of the substrate and actual shape of the

Abstract: The temperature measuring system using optical interference includes a light source which generates measuring light; a spectroscope which measures an interference intensity distribution that is an intensity distribution of reflected light; optical transfer mechanisms which emit light reflected from a surface and a rear surface of the object to be measured to the spectroscope; an optical path length calculation unit which calculates an optical path length by performing Fourier transformation; and a temperature calculation unit which calculates a temperature of the object to be measured on the basis of a relation between optical path lengths and temperatures. The light source has a half-width at half-maximum of a light source spectrum that satisfies conditions based on a wavelength span of the spectroscope. The spectroscope measures the intensity distribution by using the number of samplings that satisfies conditions based on the wavelength span and a maximum measurable thickness.

Abstract: Disclosed herein are representative embodiments of methods, apparatus, and systems for determining the temperature of an object using an optical pyrometer. Certain embodiments of the disclosed technology allow for making optical temperature measurements that are independent of the surface emissivity of the object being sensed. In one of the exemplary embodiments disclosed herein, a plurality of spectral radiance measurements at a plurality of wavelengths is received from a surface of an object being measured. The plurality of the spectral radiance measurements is fit to a scaled version of a black body curve, the fitting comprising determining a temperature of the scaled version of the black body curve. The temperature is then output. The present disclosure is not to be construed as limiting and is instead directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone or in various combinations and subcombinations with one another.

Abstract: A plasma processing apparatus and a temperature measuring method that may measure a temperature of an object in a processing chamber by a low-coherence interferometer without forming a hole in a holding stage or an upper electrode of the plasma processing apparatus, thereby performing a plasma process of a substrate with high precision and uniformity. The plasma processing apparatus is implemented by disposing a light source collimator outside of a light source window, disposing a light-receiving collimator outside of a light-receiving window, allowing a measurement light emitted from the light source collimator to pass through the light source window to be obliquely emitted to a surface of the object to be measured, and allowing the reflected measurement light to pass through the light-receiving window to be incident on the light-receiving collimator. The temperature of the object in the processing chamber may be measured by the low-coherence interferometer.

Abstract: A method, apparatus, and a computer program is provided. The method comprises: determining an ambient light value from ambient light data provided by at least one ambient light sensor, in dependence upon the spectral distribution of the ambient light data provided by the at least one ambient light sensor and a manufacturer of the at least one ambient light sensor.

Abstract: Embodiments of the present invention generally relate to methods and apparatus for measuring, calibrating, and controlling substrate temperature during low temperature and high temperature processing.

Abstract: A method for characterizing a surface comprises rotating a carrier about an axis of rotation where the carrier has a top surface adapted to hold at least one semiconductor wafer with a major surface of the wafer extending generally transverse to the axis of rotation. A surface characterization tool is moved over a plurality of positions relative to the top surface of the carrier, where a measurement location over the top surface of the carrier is changed while said top surface of the carrier is heated to a predetermined temperature. Characterization signals over the plurality of positions with the surface characterization tool are produced and contain information about the heated top surface of the carrier, or when semiconductor wafers are held on the carrier, information about the semiconductor wafer can also be obtained.

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 optical measurement instrument includes one or more temperature sensors (122) arranged to measure sample well specific temperatures from sample wells (111-117) arranged to store samples (103-109) to be optically measured. A processing device (121) of the optical measurement instrument is arranged to correct, using a pre-determined mathematical rule, measurement results obtained by the optical measurements on the basis of the measured sample well specific temperatures. Hence, the adverse effect caused by temperature differences between different samples on the accuracy of the temperature correction of the measurement results is mitigated.

Abstract: A measuring device is provided for measurement of parameters, in particular for measuring the temperature, in molten masses, in particular in molten metal or molten cryolite masses having a melting point above 500° C. The measuring device has an optical fiber for receiving radiation from the molten mass and a cable reel having an external circumference for winding up the optical fiber and an internal space surrounded by the external circumference. A distributor and a mode filter for the optical fiber are arranged in the internal space.

Abstract: A temperature measuring apparatus includes a light source, a first splitter, a second splitter, a reference beam reflector, an optical path length adjuster, a reference beam transmitting member, a first to an nth measuring beam transmitting member and a photodetector. The temperature measuring apparatus further includes an attenuator that attenuates the reference beam reflected from the reference beam reflector to thereby make an intensity thereof closer to an intensity of the measurement beam reflected from the temperature measurement object.

Abstract: A method for calibrating distributed temperature sensing (DTS) systems is disclosed. The method includes: receiving temperature data associated with one or more locations along a length of an optical fiber; calculating a set of unique calibration coefficients specific to each of the one or more locations along the fiber length; and applying the set of calibration coefficients specific to each of the one or more locations along the fiber length to the temperature data for calibrated correction thereof. Also disclosed is a system for calibrating DTS data and a wellbore for providing calibrated DTS data.

Abstract: An apparatus for measuring environmental parameters includes: an optical fiber sensor configured to be disposed along a path in an environment to be measured, the path of the optical fiber sensor defining a longitudinal axis; and at least one section of the optical fiber sensor configured so that an entire length of the at least one section is exposed to an at least substantially homogeneous environmental parameter, at least part of the at least one section extending in a direction having a radial component relative to the longitudinal axis.

Abstract: A dual parameter sensor for sensing temperature and mechanical or chemical or related information is disclosed. The sensor is formed of an optical waveguide suitable for use in-situ in a high temperature environment having a Bragg grating written into a core region thereof with short-pulsed electromagnetic radiation. By noting the thermal Black Body radiation level above 650° C., wavelength shifts due to temperature can be decoupled from wavelength shifts due to the other parameter being sensed. Advantageously the thermal radiation can be used as an optical source to probe the Bragg grating, considerably simplifying the interrogating apparatus, removing the need for an extrinsic optical source to probe the sensor.

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 system for monitoring parameters of an energy storage system having a multiplicity of individual energy storage cells. A radio frequency identification and sensor unit is connected to each of the individual energy storage cells. The radio frequency identification and sensor unit operates to sense the parameter of each individual energy storage cell and provides radio frequency transmission of the parameters of each individual energy storage cell. A management system monitors the radio frequency transmissions from the radio frequency identification and sensor units for monitoring the parameters of the energy storage system.

Abstract: A temperature measurement apparatus includes a light source; a first splitter that splits a light beam into a measurement beam and a reference beam; a reference beam reflector that reflects the reference beam; an optical path length adjustor; a second splitter that splits the reflected reference beam into a first reflected reference beam and a second reflected reference beam; a first photodetector that measures an interference between the first reflected reference beam and a reflected measurement beam obtained by the measurement beam reflected from a target object; a second photodetector that measures an intensity of the second reflected reference beam; and a temperature calculation unit. The temperature calculation unit calculates a location of the interference by subtracting an output signal of the second photodetector from an output signal of the first photodetector, and calculates a temperature of the target object from the calculated location of the interference.

Abstract: A temperature probe for use in oil-filled transformers comprises an optical fiber, a temperature sensitive member, and a protective cylindrical sheath. The optical fiber and the sensitive member are located in the protective sheath, and continuous longitudinal slit is defined along the length of the sheath to allow oil to flow therein. The optical fiber is mounted in and to the sheath using a bonding material and at a distance from the sheath. The sensitive member is adhesively mounted to the optical fiber, within the sheath, and at a distance thereof.

Abstract: An optical pyrometer includes a receiving part having a receiving end for receiving light radiation of a heating unit, and a case part covering the receiving part, except for the receiving end of the receiving part, wherein a cross-sectional area of the receiving end of the receiving part perpendicular to a lengthwise direction of the receiving end of the receiving part decreases toward an end portion of the receiving end of the receiving part.

Abstract: The interference optical system includes a light source, a collimator, a light-receiving element, a tunable filter, and a calculation apparatus. The collimator emits measuring light from the light source to a first main surface of the object, and receives reflected light from the first main surface and a second main surface. The light-receiving element acquires an intensity of light from the collimator. The tunable filter sweeps a wavelength of the light incident to the light-receiving element. The calculation apparatus measures an interference intensity distribution that has wavelength dependence and is an intensity distribution of the reflected light from the first main surface and the second main surface, and measures the thickness or the temperature of the object based on a waveform obtained by Fourier transforming the interference intensity distribution.

Abstract: Embodiments of the present invention generally relate to apparatus for and methods of measuring and monitoring the temperature of a substrate having a 3D feature thereon. The apparatus include a light source for irradiating a substrate having a 3D feature thereon, a focus lens for gathering and focusing reflected light, and an emissometer for detecting the emissivity of the focused reflected light. The apparatus may also include a beam splitter and an imaging device. The imaging device provides a magnified image of the diffraction pattern of the reflected light. The method includes irradiating a substrate having a 3D feature thereon with light, and focusing reflected light with a focusing lens. The focused light is then directed to a sensor and the emissivity of the substrate is measured. The reflected light may also impinge upon an imaging device to generate a magnified image of the diffraction pattern of the reflected light.

Abstract: The monitoring system for a gas turbine engine including a viewing tube assembly having an inner end and an outer end. The inner end is located adjacent to a hot gas flow path within the gas turbine engine and the outer end is located adjacent to an outer casing of the gas turbine engine. An aperture wall is located at the inner end of the viewing tube assembly and an optical element is located within the viewing tube assembly adjacent to the inner end and is spaced from the aperture wall to define a cooling and purge chamber therebetween. An aperture is defined in the aperture wall for passage of light from the hot gas flow path to the optical element. Swirl passages are defined in the viewing tube assembly between the aperture wall and the optical element for passage of cooling air from a location outside the viewing tube assembly into the chamber, wherein swirl passages effect a swirling movement of air in a circumferential direction within the chamber.

Abstract: A new step-index multimode pure silica core fiber for DTS (Distributed Temperature Sensing) system particularly useful for downhole environments is disclosed and described. The new sensor system provides optimum tradeoffs between coupling power, spatial resolution, and temperature resolution.