Abstract: A colorimetric based sensor system includes a low power communication system to harvest energy from an interrogator and to broadcast information to the interrogator; a controller operatively connected to the low power communication system; a light emitter, operatively connected to the controller, to emit light; a light detector, operatively connected to the controller, to convert receive light into electrical signals; and a colorimetric based sensor, having a changeable color patch and in optical communication with the light detector and the light emitter, to measure a condition of an object of interest.

Abstract: Disclosed in the present invention is a graph theory-based method for locating an instability fault source in a direct-current microgrid. The method includes: collecting key electrical feature quantities through an instability fault feature collection and extraction link to accurately capture an instability oscillation phenomenon, and utilizing wavelet packet decomposition to construct fault feature vectors; then, according to the structure of the direct-current microgrid, constructing an undirected graph model G=(V, E, X), which lays a foundation for analysis; applying a graph convolutional neural network for deep learning and training to further improve the accuracy and efficiency of diagnosis; deploying the trained model in an actual system to effectively achieve accurate fault diagnosis and location of an instability source. Also provided in the present invention is a device for locating an instability fault source in a direct-current microgrid.

Abstract: An electric apparatus is provided that includes a fiber optic system and an electric conductor. The fiber optic system includes an inner cladding, an outer cladding and a fiber optic core between the inner cladding and the outer cladding. The electric conductor extends longitudinally along a centerline within the fiber optic system. The centerline may be a centerline of any one or more or all of the fiber optic system, the inner cladding, the outer cladding, the fiber optic core and/or the electric conductor.

Abstract: A wound treatment apparatus can include a wound dressing configured to be positioned proximate to a wound. Multiple optical fibers positioned at least partly in the wound dressing can include a first optical fiber and a second optical fiber. The wound treatment apparatus can include an emitter and a detector. The emitter can emit first electromagnetic radiation into the first optical fiber so that the first optical fiber passes the first electromagnetic radiation. The detector can generate a signal responsive to second electromagnetic radiation that exits the second optical fiber and contacts the detector.

Abstract: Optical fibre based measurement system having a system for generating radiation (Z) with monotonically tuneable wavelength during sweep periods, an optical path (T) and a detector (D) connected to the system for generating radiation (Z) via the optical path (T). The optical path (T) comprises the interferometer (I) comprising the multi-port element (EW) and the attached measuring optical fibre (F) sensitive to at least two environmental parameters, the mode excitation system (P) adapted for excitation in the measuring optical fibre (F) of at least the measuring mode (Mn1) with the first effective refractive index and the measuring mode (Mn2) with the second effective refractive index, having different sensitivity to these two parameters. The measurement system comprises the processing unit (UP) to which the detector (D) is connected via the analogue-to-digital converter (ADC), and the processing unit (UP) is adapted to generate the control signal for the system for generating radiation (Z).

Abstract: A fiber-optic system for use in optical sensing includes a multicore sensing fiber having at least two cores of which each of the at least two cores has a first core diameter, and a multicore lead-in fiber having at least two cores including a position corresponding with the position of the at least two cores of the multicore sensing fiber. Each of the at least two cores of the multicore lead-in fiber have a second core diameter. The second core diameter is substantially larger than the first core diameter. The system further includes an alignment means for aligning the multicore sensing fiber and the multicore lead-in fiber so that the lead-in fiber and the multicore sensing fiber are configured for coupling radiation between the fibers through the cores.

Abstract: According to one embodiment, a structure evaluation system includes at least three or more sensors, a position locator, and an evaluator. The three or more sensors are arranged on surfaces different from a surface to which an impact is applied with respect to a structure at different intervals in a first direction of the structure and a second direction orthogonal to the first direction and detects elastic waves generated from the structure. The position locator locates a position of a source in which the elastic waves are generated on the basis of the elastic waves detected by each of the three or more sensors. The evaluator evaluates a deterioration state of the structure on the basis of information based on a position location process of the position locator and information indicating a position where the impact is applied.

Abstract: The invention provides a multi-well plate reader for providing simultaneous transmission of stimulation light to, and detection of emission light from, individual wells of a multi-well plate at a plurality of distinct wavelengths.

Abstract: An apparatus comprises a flexible filament structure, and a fiber optic sensor with a buffer material that locally bonds the fiber optic sensor to the flexible filament structure to create a bond between the fiber optic sensor and the flexible filament structure to transfer strain from the flexible filament structure to the fiber optic sensor to allow the fiber optic sensor to detect strain on the flexible filament structure while maintaining flexibility in the flexible filament structure. A fiber optic interrogator may be optically coupled to the fiber optic sensor and configured to measure strain. A method comprises embedding a fiber optic sensor with a buffer material in or on a flexible filament structure. Thereafter, the buffer material is activated via heating or curing to locally adhere the fiber optic sensor to the flexible filament structure to create a local bond. The local bond transfers strain from the flexible filament structure to the fiber optic sensor.

Abstract: Provided is an optical micro-electro-mechanical system (MEMS) based monitoring system, comprising: a broadband light source, a tunable optical filter (TOF), an optical etalon, a plurality of optical receivers, a plurality of optical couplers, and a plurality of optical MEM sensors; the TOF is configured to capture a transmission, reflection or interference spectrum of the optical MEMS sensors; wherein the peak or depression wavelength in the transmission, reflection or interference spectrum corresponds to a parameter of the pressure, temperature or stress, and the peak or depression wavelength can be obtained by comparing the spectrum with the periodic spectrum of the optical etalon, the optical etalon has an absolute wavelength mark; and the optical MEMS sensor comprises an optical MEMS resonator. The parameter of the pressure, temperature or stress can be obtained by the peak or depression wavelength in the transmission, the reflection or the interference spectrum of the optical MEMS sensor.

Abstract: A system includes an optical waveguide, provided as a component of a first part, and at least one sensor system, provided as a component of a second part. The second part is movable relative to the first part, and the optical waveguide radiates light laterally on the side. The sensor system detects the light intensity of the laterally emitted light emitted by the optical waveguide. A grating is provided between the sensor system and the optical waveguide.

Abstract: A multi-fibre optical probe for spectroscopically analysing high concentration mediums (i.e. about 40 wt % or higher solid particulates), an extruder comprising a multi-fibre optical probe, use of said multi-fibre optical probe are provided. Methods of generating a predictive model, determining the value of a parameter of a solid particulate dispersion and manufacturing a solid particulate dispersion are also provided.

Abstract: The disclosure extends to methods, devices, and systems for removing speckle from a coherent light source, such as laser light. The methods, devices, and systems help eliminate or reduce speckle introduced from a coherent light source, such as laser light, by utilizing the teachings and principles of the disclosure.

Abstract: An in-situ fiber-optic temperature field measurement is disclosed that can allow process monitoring and diagnosis for thermoplastic composite welding and other applications. A distributed fiber-optic sensor can be permanently embedded in a thermoplastic welded structure when it is welded and left there to perform lifelong monitoring and inspection. The fiber optic sensor can include a dissolvable coating, or a coating matched to the composite material to be welded. Other applications include in-situ fiber-optic temperature field measurement on thermoset composite curing (autoclave), for thermoplastic and thermoset composites during compression molding, and for fiber-optic field measurements on freeze/thaw of large items of public health interest, such as stored or transported foodstuffs.

Abstract: A distributed acoustic system (DAS) may comprise an interrogator and an umbilical line attached at one end to the interrogator, a downhole fiber attached to the umbilical line at the end opposite the interrogator. The interrogator may further include a proximal circulator, a distal circulator connected to the proximal circulator by a first fiber optic cable, and a second fiber optic cable connecting the proximal circulator and the distal circulator.

Abstract: Provided are three dimensional, stretchable, optical sensor networks that can localize deformations. The devices described herein are suitable for uses in soft robots to determine the position of external contact, such as touching, and possibly internal deformations that may be caused by actuation. Sensor networks of the present disclosure contain a substrate, such as a 3D lattice, and cores having a cladding, such as air. Light passes through the cores and upon deformation of the substrate, cores may come into contact, allowing light to couple between cores due to frustrated total internal reflection. The resulting changes in intensity in the cores can be used to determine the placement and magnitude of deformation.

Abstract: In a method for interrogating at least one optical sensor coupled to an optical path, at least two time-shifted optical signals are fed into the optical path and reflected optical signals of the at least two probe signals created by the at least one optical sensor are detected. Each detected reflected optical signal is assigned to one of the at least one optical sensor and a correct optical frequency is assigned to each detected reflected optical signal. An absolute value or a value range or a change of a value or value range of the parameter to be sensed is determined from the one or more of the following physical conditions: the optical reflection signals, the reflectivity of the at least one optical sensor, and the frequency of each detected optical reflection signal, or from one or more dependencies that link these physical conditions.

Abstract: The vehicle hull with an interferometric fiber-optic gyroscope includes an outer hull, an inner hull arranged within the outer hull, and an interferometric fiber-optic gyroscope. A fiber optic coil of the interferometric fiber-optic gyroscope is wound around the inner hull in a space between the inner hull and the outer hull. As a non-limiting example, the vehicle may be a dual-hull submarine, and the fiber optic coil may be would around the pressure hull of the submarine within the space between the pressure hull and the light hull. The interferometric fiber-optic gyroscope also includes a light source and an optical modulator in optical communication therewith. The fiber optic coil is optically coupled at two ends thereof to the optical modulator for receiving two counter-propagating light beams therefrom. A photodetector is optically coupled with the optical modulator for receiving a recombined light beam produced by the optical modulator.

Abstract: Disclosed is a structure (e.g., a lab-on-chip structure) including a substrate, an insulator layer on the substrate, and at least one optical ring resonator. Each ring resonator includes cladding material on the insulator layer and, embedded within the cladding material, a first waveguide core with an input and an output, and second waveguide core(s) (e.g., ring waveguide core(s)) positioned laterally adjacent to the first waveguide core. A reservoir is below the ring resonator within the insulator layer and substrate such that surfaces of the waveguide cores are exposed within the reservoir. During a sensing operation, the waveguide core surfaces contact with fluid within the reservoir and a light signal at the output of the first waveguide core is monitored (e.g., by a sensing circuit, which in some embodiments is also coupled to a reference optical ring resonator) and used, for example, for spectrum-based target identification and, optionally, characterization.

Abstract: An optical fiber with one or more microgratings is disclosed. Methods and apparatus are described for making an optical fiber with one or more microgratings. Methods and apparatus are described for an optical fiber with one or more microgratings Optical sensing methods and an optical sensing system effectively decouple strain range from the laser tuning range, permit the use of a smaller tuning range without sacrificing strain range, and compensate for ambiguity in phase measurements normally associated with smaller tuning ranges.

Abstract: Methods and systems for analyzing an industrial structure are provided. With a plurality of sensors (e.g. FBGs and/or piezoelectric transducers and/or electromagnetic acoustic transducers) deployed in, on or in proximity to the structure, sensors are interrogated and a function representative of the impulse response of the structure is determined by passive inverse filter. Subsequently, a map of the propagation of the elastic waves through the structure is determined via various modalities, and in particular by tomography (of bulk or guided waves, by analysis of time of flight or of the complete signal). Embodiments especially relate to the management of the number and position of the sensors, to the use of artificial noise sources, and to automatically controlling the sensors and/or noise sources to monitor the health of the structure, or even to view the dynamic behavior of the structure.

Abstract: A distributed acoustic system (DAS) method and system. The system may comprise an interrogator and an umbilical line comprising a first fiber optic cable and a second fiber optic cable attached at one end to the interrogator. The DAS may further include a downhole fiber attached to the umbilical line at the end opposite the interrogator and a light source disposed in the interrogator that is configured to emit a plurality of coherent light frequencies into the umbilical line and the downhole fiber. The method may include generating interferometric signals of the plurality of frequencies of backscattered light that have been received by the photo detector assembly and processing the interferometric signals with an information handling system.

Abstract: A device for detecting wear of a wear member composed of electrically resistive material. The wear member comprises at least two electrodes separated from each other, where each electrode overlies, or is embedded in, an outer surface of the electrically resistive material. One of the electrodes is connected to a resistor at a measurement node to form a resistive voltage divider. A voltage measurement device measures a change in voltage at the measurement node, where the change is voltage is indicative of the degree of removal of resistive material from a face of the wear member and where the change in voltage is continuously variable and not limited to discrete wear levels.

Abstract: Plasmonic optical fibers, plasmonic optical sensors and methods of manufacturing the same. A fiber core conveys an optical signal therewithin and provides a plasmonic sensing area exposed to a fluid. The plasmonic sensing area is formed only on a section of an external surface of the fiber core. The plasmonic sensing area provides an interface within the section of the external surface for the conveyed signal to at least partially exit the fiber core and cause a modified optical signal to be conveyed in the fiber core. An optical signal generator may provide the optical signal to the plasmonic optical fiber, an optical signal receiver may discriminate the conveyed optical signal from the modified optical signal and a processor module may analyze the modified optical signal and identifies physical characteristics of the fluid present at the sensing area.

Abstract: Aspects of the present disclosure describe distributed fiber optic sensing (DFOS)—distributed acoustic sensing (DAS) based systems, methods, and structures that advantageously enable and/or facilitate the determination of natural frequency(ies) of civil infrastructures.

Abstract: The present invention relates to a medical system using an interventional elongated medical device having an optical fiber configured for optical shape sensing of the medical device. The system comprises a detection unit configured to detect a confined manipulation section along the medical device for manipulation by a user without an interaction interface arranged on the medical device and an analysis unit configured to analyze a user manipulation applied to the manipulation section based on optical shape sensing of the medical device in the manipulation section and to trigger an event in the medical system, if the analysis unit identifies the user manipulation in the manipulation section as a specific manipulation associated with the event to be triggered.

Abstract: System and method for in-process cure monitoring of a material utilizes one or more sensors such as fiber Bragg gratings (FBGs) or phase-shifted FBGs (PS-FBGs) and at least one optical line fiber connected to the sensor(s). The sensor(s) and the optical line may be embedded in the material prior to curing the material may comprise a fiber reinforced polymer. Waves are excited into the material during curing thereof to form guided waves that propagate through the material. At least one wave metric of the guided waves is measured utilizing the sensor(s).

Abstract: Disclosed is detection apparatus for flow deformation of foundation layer in horizontal direction including: housing, rotation assembly rotatably disposed within accommodation cavity of the housing, and measurement assembly including first optical fiber lead wire, first optical fiber sensor disposed on first optical fiber lead wire, second optical fiber lead wire, and second optical fiber sensor disposed on second optical fiber lead wire, and disposed within the accommodation cavity. First optical fiber sensor is configured to measure tensile strain of first optical fiber lead wire and first optical fiber sensor before and after the rotation assembly rotates; second optical fiber sensor is configured to measure tensile strain of second optical fiber lead wire and second optical fiber sensor before and after the rotation assembly rotates, to obtain strain amount and displacement change amount, and further to obtain flow deformation degree and flow deformation direction of soil mass of the foundation layer.

Abstract: Apparatuses, systems and methods for controlling production of hydrocarbon material disposed within a subterranean formation are provided. In one aspect, a method is provided for producing hydrocarbon material by displacement via flow communication station of a production well. Working states of the production well are analyzed by setting the flow communication stations in the working state, producing hydrocarbon material while in the working state, and sensing a characteristic of the produced material while in the working state. A working state that optimizes operating parameters of the of the production well is determined based on the sensed characteristic, and the production well is subsequently operated in that working state.

Abstract: A physiological sensor has light emitting sources, each activated by addressing at least one row and at least one column of an electrical grid. The light emitting sources are capable of transmitting light of multiple wavelengths and a detector is responsive to the transmitted light after attenuation by body tissue.

Abstract: Implementations described and claimed herein provide systems and methods for surface monitoring. In one implementation, a target surface ahead of a vehicle is illuminated with light emitted from at least one light source. Image data of the target surface is captured from returns collected by at least one imager. At least one surface property of the target surface is measured using the image data. A set of friction metrics is generated from the at least one surface property. An estimated coefficient of friction for the target surface is determined from the set of friction metrics.

Abstract: Aspects of the present disclosure describe distributed fiber optic sensing (DFOS)-distributed acoustic sensing (DAS) based systems, methods, and structures that advantageously enable and/or facilitate the monitoring of civil infrastructures via acoustic wave speed measurements.

Abstract: A fluid properties sensing system includes an optical sensor which generates a sensor signal based on received laser light, a light source which transmits laser light through a transmitting fiber to a sensor head, a receiver that detects a portion of the laser light from a receiving fiber through an evanescent field of the transmitting fiber when the laser light radiates through a transmitting fiber wall of the transmitting fiber and interacts with a fluid medium at an interface of the sensor and the fluid medium, and a processor. The fibers are coupled at one end through the evanescent field to form the sensor head disposed in a flow field and to interact with the fluid medium. The processor identifies a change in the sensor signal based on a detected portion of the laser light resulting from an interaction of the sensor head with the fluid medium.

Abstract: A method of detecting removal of a maintenance hatch includes transmitting an optical pulse along an optical fiber, wherein a first portion of the optical fiber is proximate to the maintenance hatch. The method further includes detecting backscatter light from the optical fiber using a sensor. The method further includes determining information related to the first portion of the optical fiber based on a comparison of the detected backscatter light and a trained model. The method further includes identifying whether the maintenance hatch has been removed based on the determined information.

Abstract: Embodiments of the present invention provide a unique new approach to generating operating condition information used for assessing flow assurance and structural integrity. More specifically, apparatuses, systems and sensor housing assemblies configured in accordance with embodiments of the present invention utilize fiber optic sensors for enabling monitoring of operating condition information within one or more elongated tubular members within a subsea environment. To this end, such fiber optic sensors connected by lengths of optical fiber are strategically placed at a plurality of locations along a length of each elongated tubular member thereby allowing critical operating conditions such as strain, temperature and pressure of the elongated tubular member and/or a fluid therein to be monitored. A viscous media is used for mitigating attenuation associated with exposure of optical fiber exposed to forces generated by pressure within the subsea environment.

Abstract: The present invention is advantageous in that the shape of the catheter can be sensed by detecting the position of bending of the catheter body, the direction thereof, the angle thereof, and the curvature thereof through a triplet calculation of information regarding three wavelengths that have undergone a transition along respective FBGs provided on three optical cores.

Abstract: A medical manipulator system according to the present invention is provided with: a manipulator; a manipulator channel; a route that extends along the manipulator channel; a shape sensor that detects shape information of the manipulator channel; a shape-sensor driving portion that causes the shape sensor to be driven; a manipulator driving portion that causes the manipulator to be driven; a positional-information calculating portion that calculates positional information of the shape sensor on the basis of a driven amount of the shape-sensor driving portion; a shape estimating portion that estimates a bent shape of the manipulator on the basis of the shape information of the manipulator channel and the positional information; a control-parameter calculating portion that calculates a control parameter of the manipulator from the bent-shape information; and a manipulator controller that controls the manipulator on the basis of the control parameter.

Abstract: Example embodiments include an optical interrogation system with a sensing fiber having a single core, the single core having multiple light propagating modes. Interferometric apparatus probes the single core multimode sensing fiber over a range of predetermined wavelengths and detects measurement interferometric data associated with the multiple light propagating modes of the single core for each predetermined wavelength in the range. Data processing circuitry processes the measurement interferometric data associated with the multiple light propagating modes of the single core to determine one or more shape-sensing parameters of the sensing fiber from which the shape of the fiber in three dimensions can be determined.

Abstract: A method is provided of inspecting a nested multi-layer structure including a first and second electrically conductive layer and a third layer disposed behind the second conductive layer. The method includes deploying a sensor device including an electromagnetic acoustic transducer to a borehole location proximate to the structure, generating a drive signal including a plurality of frequencies, applying an electrical current signal to the sensor device based on the drive signal and inducing currents in the first conductive layer that induce currents generating acoustic signals having the plurality of frequencies, detecting a first set of resonant frequencies based on received electromagnetic signals, detecting a second set of resonant frequencies based on received acoustic signals, estimating a property of the first and/or the second conductive layer based on the first set of resonant frequencies, and estimating a property of the third layer based on the second set of resonant frequencies.

Abstract: A multi-dispersive spectrometer is provided in which the spectrometer comprises an optical system configured to direct an excitation signal from an excitation light source toward a sample, receive a spectroscopy signal from the sample, and direct the spectroscopy signal toward the detector. The optical system comprises a movable optical component adapted to move the spectroscopy signal relative to at least one sensor of the detector and the detector is adapted to detect a plurality of discrete shifted spectroscopy signals. A method of obtaining a Raman spectrum from a sample is also provided. The method comprises directing an excitation signal from an excitation light source toward a sample; receiving a spectroscopy signal from the sample; and directing the spectroscopy signal toward a detector, wherein the spectroscopy signal is moved relative to at least one sensor of the detector to provide a plurality of discrete shifted spectroscopy signals.

Abstract: Methods and apparatus for tracking movement over the ground or other surfaces of a buried utility locator during a utility locate operation are disclosed.

Abstract: A system and technique for obtaining two or more distributed measurements from an optical sensing fiber deployed along a desired measuring path are disclosed. Interrogating probes from two or more different distributed measuring systems are combined and launched into the sensing fiber. Backscattered light generated in response to the combined interrogating probes is separated into portions and each portion is provided to a respective distributed measuring instrument. In this manner, distributed measurements corresponding to different parameters of interest, such as temperature and pressure, along the measuring path can be measured simultaneously using the same sensing fiber.

Abstract: A monitoring system for an electric vehicle that draws current from a conductor by means of a current collector that contacts a conductor in operation of the electric vehicle. The monitoring system includes a plurality of sensor modules throughout the current collector, wherein each sensor module comprises a plurality of FBG (Fibre Bragg Grating) sensors. Sensors of each module are arranged in a geometric pattern that compensates for temperature induced wavelength changes in the FBG sensors of each module. An optical source illuminates each sensor module and an optical coupler optically couples the optical source to each sensor module. An optical signal interpretation module receives optical signals from each sensor module wherein the optical signals are generated by the sensor modules in response to illumination of the sensor modules, wherein the interpretation module is configured to determine from the optical signals, a temperature-independent strain measurement for each sensor module.

Abstract: A microscale photoacoustic sensor uses the detection of ultrasound waves generated by a sample in response to incident light absorption to perform photoacoustic spectroscopy, imaging, and microscopy. The microscale photoacoustic sensor, including components to excite a sample and detect ultrasound waves, may be integrated onto a single chip. The microscale photoacoustic sensor may excite a sample using a metasurface collimator. The metasurface collimator includes an array of diffraction grooves to collimate an excitation beam uniformly out of the plane of the sensor to create a wide and homogeneous beam spot. The microscale photoacoustic sensor may detect ultrasound waves using an optical photoacoustic transducer. The optical photoacoustic transducer includes a resonator on a mechanical membrane to detect ultrasound waves with high sensitivity. The microscale photoacoustic sensor may be used in applications such as deep-tissue neural imaging or microfluidic biological screening.

Abstract: A measuring system (1) comprises a sensor (6) arranged to be attached to a subject for obtaining a measured value representing a physical or a physiological quantity of the subject. The measuring system further comprises means for deriving a subject-related value from the measured value. The sensor is arranged to be attached at one of a plurality of positions on the subject. The measuring system further comprises means for establishing the position of the sensor on the subject. The means for deriving the subject-related value is arranged for deriving the subject-related value also in dependence on the position of the sensor on the subject.

Abstract: A temperature sensor for measuring temperature is described. The sensor comprises a fibre optic cable (104) comprising optical fibre (102) and an interrogator unit (106) configured to interrogate the optical fibre with electromagnetic radiation, detect any radiation that is Rayleigh backscattered within the optical fibre and determine a measurement signal indicative of temperature changes for at least one longitudinal sensing portion of the optical fibre. A controllable thermal element, which may be a heating element, such as an electrically conducting element (108), is arranged along the length of the fibre optic cable (104) and in thermal communication with the fibre optic cable (104). A controller (110) is configured to generate a thermal variation in the controllable thermal element, e.g. by generating a time varying electric current in the electrically conducting element (108).

Abstract: A device for a lacquer transfer includes a transfer roller mounted at and rotatable relative to a frame. The roller includes a cylindrical support-body, first ring-element, second ring-element, and a tire including a middle-section forming a circumferential outer contact surface with depressions, the roller configured to roll with the outer contract surface on a work surface of a workpiece for transferring lacquer from the outer contact surface and the depressions to the work surface. The tire includes two annular end-sections attached to a cylindrical outer shell of the support-body resulting in two axially separated and circumferentially extending connections, the tire, connections, and outer shell of the support-body being fluid-tight. The first and second ring-elements are in the first cavity seated on the support-body at a distance in an axial direction of the roller from one another and the middle-section of the tire between the first and second ring-elements is prestrained in the axial direction.

Abstract: A distributed acoustic system (DAS) may comprise an interrogator and an umbilical line attached at one end to the interrogator, a downhole fiber attached to the umbilical line at the end opposite the interrogator. The interrogator may further include a proximal circulator, a distal circulator connected to the proximal circulator by a first fiber optic cable, and a second fiber optic cable connecting the proximal circulator and the distal circulator.

Abstract: A system and method for detecting dynamic strain of a housing. The system includes an optical fiber linearly affixed along a surface of a length of the housing and an interrogator comprising a laser source and a photodetector. The optical fiber comprises at least one pair of fiber Bragg gratings (FBGs) tuned to reflect substantially identical wavelengths with a segment of the optical fiber extending between the FBGs. The segment of the optical fiber is linearly affixed along the surface of the housing. The interrogator is configured to perform interferometry by shining laser light along the optical fiber and detecting light reflected by the FBGs. The interrogator outputs dynamic strain measurements based on interferometry performed on the reflected light.

Abstract: A metrology measurement apparatus may include one or more illumination sources, a beamsplitter configured to receive illumination from the one or more illumination sources from an illumination pathway and direct the illumination along a measurement pathway, and an objective lens. The objective lens may direct the illumination from the measurement pathway to a sample, collect light from the sample, and direct the collected light along the measurement pathway to the beamsplitter such that the beamsplitter may direct the collected light along a collection pathway to a detector. The apparatus may further include a pupil-plane scanner along the measurement pathway with a pupil relay and a deflector in a relayed pupil plane such that adjusting the deflector adjusts a position of the illumination spot on the sample without modifying a position of the illumination pupil distribution or a position of a distribution of the collected light along the collection pathway.