Abstract: A method for prompting an evasive maneuver by at least one first autonomous or semi-autonomous vehicle. A vehicle state of the at least one first vehicle is ascertained by a control unit of the at least one first vehicle. Vehicles within a minimum distance are ascertained by the at least one first vehicle. The ascertained data of the at least one first vehicle are transmitted within the minimum distance to ascertained vehicles by the at least one first vehicle in order to prompt an adaptation of a trajectory and/or a speed of the ascertained vehicles. The at least one first vehicle being transferred into a safe state. A system is also provided.

Abstract: A combination weighing device includes: an electroconductive plate opposed, with an interval, to an electroconductive part enabling detection of water intrusion inside the combination weighing device; a voltage wire for application of voltage to the electroconductive plate; and a detector that detects a potential difference between the electroconductive part and the electroconductive plate, wherein the detector or a controller of the combination weighing device determines presence or absence of water intrusion inside the interval, based on the detected potential difference.

Abstract: An imaging system that includes an image sensor and imaging optics is provided. The image sensor has a sensing surface and it captures images of a scene. The imaging optics is optically coupled to the image sensor and is configured to form the images of the scene onto the sensing surface of the image sensor. The imaging optics includes a sensor-adjacent optical element having an exit surface located in close proximity to the sensing surface of the image sensor. The exit surface of the sensor-adjacent optical element and the sensing surface of the image sensor are spaced apart by a gap having a gap width enabling evanescent-wave coupling from the exit surface to the sensing surface for light having wavelengths within the sensor spectral range.

Abstract: A system to detect a position of a cannula may include a cannula, which may include a distal tip and an inner lumen. Also, the system may include an optical fiber, which may be disposed within the inner lumen of the cannula and may include a first end, a second end, and a U-shaped portion disposed between the first end and the second end. The U-shaped portion may be at least proximate the distal tip. Further, the system may include a light emitter, which may be coupled with the first end of the optical fiber, and a light receiver, which may be coupled with the second end of the optical fiber. Moreover, the system may include an electronic processor. The electronic processor may be coupled with the light receiver and configured to detect a decrease in an intensity of light received at the light receiver.

Abstract: A microcirculation detection system including a heating device, a photosensitive array and a processing unit is provided. The heating device is used to heat a skin area. The photosensitive array is used to detect outgoing light from the skin area, and output a plurality of brightness variation signals respectively at different time points within a heating period. The processing unit is used to calculate a change of an array energy distribution varied within the heating period according to the plurality of brightness variation signals to accordingly identify a microcirculation state.

Abstract: Provided herein are imaging systems for a patient comprising an imaging probe and an imaging assembly. The imaging probe comprises: an elongate shaft comprising a proximal end, a distal portion, and a lumen extending between the proximal end and the distal portion; a rotatable optical core comprising a proximal end and a distal end, wherein at least a portion of the rotatable optical core is positioned within the lumen of the elongate shaft; and an optical assembly positioned proximate the distal end of the rotatable optical core, the optical assembly configured to direct light to tissue and collect reflected light from the tissue. The imaging assembly is constructed and arranged to optically couple to the imaging probe. The imaging assembly is configured to emit light into the imaging probe and receive the reflected light collected by the optical assembly.

Abstract: A photodetector includes a metal layer that shields incident light and generates surface plasmon polaritons (SPPs), a light absorbing layer that absorbs the generated SPPs and allows charges excited by the absorbed SPPs and a localized electric field effect to tunnel, a dielectric formed at nanoholes in which at least a part of the metal layer is opened, and a semiconductor layer that induces the photocurrent based on an electric field effect of tunneled electrons. The SPPs form localized surface plasmons (LSPs) at an interface where the metal layer meets the dielectric.

Abstract: This application is directed to distributed fiber optic sensing particularly across multiple fiber optic ports with multiple corresponding fiber optic paths. A method is implemented to repeatedly a train of optical signals through a fiber optic network including a plurality of optical fibers distributed across a geographic area using at least one optical signal transmitter, sequentially distribute optical signals in the train through the plurality of optical fiber via corresponding optical fiber ports using an optical switching arrangement, receive backscattered optical signals from the plurality of optical fibers demodulate data from the backscattered optical signals, process the data to identify at least some of the low-frequency weight-induced disturbances, and/or sense the backscattered optical signals in a reduced frequency range. The method is useful to detect low frequency weight-induced disturbances for object tracking against high noise clutter in the higher frequency signal bands.

Abstract: A 2D spatial differentiator operates in transmission and comprises a Si Nano rod photonic crystal that can transform an image, Ein, into its second-order derivative, Eout ??2Ein, allowing for direct discrimination of the edges in the image. The use of a 2D photonic crystal allows for differentiation and edge detection in all directions with a numerical aperture (NA) up to 0.315 and an experimental resolution smaller than 4 ?m. The nanophotonic differentiator is able to be directly integrated into an optical microscope and onto a camera sensor, demonstrating the ease with which it can be vertically integrated into existing imaging systems. Furthermore, integration with a metalens is demonstrated for realizing a compact and monolithic image-processing system. In all cases, the use of the nanophotonic differentiator allows for a significant reduction in size compared to traditional systems, opening new doors for optical analog image processing in applications involving computer vision.

Abstract: A medical object for arrangement in an object under examination includes an optical fiber. The optical fiber is configured to contact at least one light source optically. The medical object further includes multiple photoacoustic absorbers that are arranged in sections along a direction of longitudinal extension of the optical fiber and/or along a periphery of the medical object. The multiple photoacoustic absorbers are configured to be arranged at least in part in the object under examination. The optical fiber is configured to conduct an excitation light emitted by the at least one light source to the multiple photoacoustic absorbers. The multiple photoacoustic absorbers are configured to be excited by the excitation light for the photoacoustic emission of ultrasound.

Abstract: Analytic sensors and methods utilize an attenuated total reflection (ATR) crystal to detect volatile compounds in an arrangement that reduces interference from compounds other than the one of interest. In particular, the components in the measurement stream are limited to those having volatilities close to that of the analyte of interest, which may be identified based on, for example, the temperature of the ATR crystal and the “dwell time”—i.e., an interval of substantially constant temperature as the ATR crystal is heated.

Abstract: A method of processing an out-coupling end of a hollow core fiber including a plurality of anti-resonance elements surrounding a hollow core, and a hollow core fiber having been so processed. The method may include performing a tapering step to form a taper in the anti-resonance elements; performing a cleaving step at the taper to form at least one tapered out-coupling end of the hollow core fiber; and performing an end processing step including further heating the out-coupling end in a controlled manner to smoothen the out-coupling end.

Abstract: An optical fibre sensing system (300) with an incident light source (309), a wavelength spectrum interrogator (313), and an optical fibre (302) with a substantially continuous fibre Bragg grating (306). An upstream portion (318) of the optical fibre has an attenuation length to light to the interrogator (313) at a first equilibrium wavelength. A downstream portion (322) of the optical fibre reflects light to the interrogator (313) when a change in temperature and/or strain at the downstream portion (322) causes a portion of the fibre Bragg grating to reflect light to the interrogator (313) at a second wavelength and at a second intensity. A processor (315) is configured to analyse the reflected spectrum (314) to determine when a portion of the fibre Bragg grating (306) is experiencing a change in temperature and/or strain based on deviation in the reflected spectrum (314) from an initial peak corresponding to the initial wavelength.

Abstract: Fiber Bragg grating (FBG) sensors are used to provide measurement of chordae tendineae forces. Two basic modes of operation are considered, The first mode is a research mode, where the FBG sensors are affixed to native chordae in situ and preferably in vivo to provide data on chordae forces in a beating heart under various conditions (e.g., normal, hypertensive, etc.), The second mode is a clinical mode, where the FBG sensor can be used to measure tension on a prosthetic neochord during the surgical procedure to implant the prosthesis.

Abstract: The present invention relates to a sensor package to be attached to an object, and the sensor package includes: a first substrate; an FBG sensor; a resin portion and a first pressure-sensitive adhesive layer positioned on the first substrate; and an adhesive layer positioned on a surface of the resin portion on a side opposite to the first substrate, in which the FBG sensor is held by the resin portion.

Abstract: An optical source switching apparatus including first optical sources, an optical cross-connect device, second optical sources, and a first coupler. The optical cross-connect device is connected to the first optical sources and the first coupler, and the first coupler is connected to the second optical source; both the first optical source and the second optical source are configured to output continuous optical energy, and the optical cross-connect device is configured to enable optical energy output by at least one of the first optical sources to enter the first coupler when at least one of the second optical sources fails; and the first coupler is configured to implement beam splitting of the optical energy output by the first optical source or the second optical source.

Abstract: An object of the present invention is to provide an immersion detection system and an immersion detection method capable of eliminating module replacement in the occurrence of immersion and simplifying system management. An immersion detection system according to the present invention includes: an immersion detection sensor having two optical fibers connected in series such that end faces of the two optical fibers abut on each other with a predetermined gap; an optical measurer that causes test light with a plurality of wavelengths to enter an optical transmission line having a plurality of the immersion detection sensors connected in series with optical fibers and measures a return loss of the test light at the immersion detection sensor for each of the wavelengths and for each of the immersion detection sensors; and a determiner that averages, for each of the immersion detection sensors, the return losses for the wavelengths and performs threshold determination on the presence or absence of immersion.

Abstract: A hybrid fiber for detection of UV light is described. The hybrid fiber includes a conductor, a first layer, a photoactive layer, a second layer, and a transparent electrode. The conductor includes a conductive material. The first layer includes a first material deposited onto the conductor. The first material is configured to transport holes and block electrons. The photoactive layer includes a photoactive material coating the first layer. The photoactive material includes a first submaterial and a second submaterial. The second layer includes a second material deposited onto the photoactive layer. The second material is configured to block holes and transport electrons. The transparent electrode includes a transparent electrode material deposited onto the second layer.

Abstract: A system and method for measuring a hydration level in human tissue. The system includes a coaxial probe have a first end configured to be in contract with human tissue and configured to be emit and receive signals associated with a spectroscopic technique and having a second end adapted to be coupled to transmit and receive circuitry. The system further includes a patch or other means coupled to the coaxial probe and configured to be adhered to human tissue so as to provide a force upon at least a portion of the coaxial probe configured to be in contact with human tissue. In embodiments, the system may further include means coupled to receive signals from the coaxial probe, for determining an amount of liquid within a portion of human tissue in contact with the first end of the probe.

Abstract: A biosensor using an exceptional point is disclosed. A biosensor according to one embodiment of the present disclosure includes: a biosensing unit configured to output wavelength-separated optical signals from destruction of an exceptional point resulting from attachment of biomolecules; a detection unit configured to convert the wavelength-separated optical signals into wavelength-separated electrical signals; an analysis unit configured to measure a beat frequency resulting from the wavelength-separated electrical signals; and a determination unit configured to determine a wavelength difference resulting from the beat frequency, thereby determining the amount of the biomolecules therefrom.

Abstract: A method of operating a shape sensing apparatus comprises receiving shape data from a first shape sensor. The first shape sensor includes a first plurality of optical cores extending between a first section and a second section of an elongated optical fiber. The method further comprises receiving shape data from a second shape sensor. The second shape sensor includes a second plurality of optical cores extending between the first and second sections of the elongated optical fiber. The method further comprises determining a shape of the elongated optical fiber between the first and second sections by combining the shape data from the first and second shape sensors.

Abstract: Provided herein include various examples of an apparatus, flow cells that include these examples of the apparatus, and methods of making these examples of the apparatus. The apparatus can include a molding layer over a substrate and covering sides of a light detection device. The molding layer comprises a first region and a second region, which, with the active surface of the light detection device, form a contiguous surface. A waveguide integration layer is between the contiguous surface and a waveguide. The waveguide integration layer comprises optical coupling structures over the first and second regions, to optically couple light waves from a light source to the waveguide. The waveguide utilizes the light waves to excite light sensitive materials in nanowells. A nanostructure layer over the waveguide comprises the nanowells. Each nanowell shares a vertical axis with a location on the active surface of the light detection device.

Abstract: The present invention relates to an optical fiber sensor, comprising an optical fiber having embedded therein at least one fiber core (14, 16, 18, 20) extending along a length of the optical fiber, the at least one fiber core having a plurality of single fiber Bragg gratings (40, 42, 44) arranged in series along the at least one fiber core (14, 16, 18, 20), wherein each fiber Bragg grating (40, 42, 44) has a single reflection spectrum around a single reflection peak wavelength when interrogated with light in an unstrained state of the at least one fiber core (14, 16, 18, 20), wherein the reflection peak wavelengths of the single reflection spectra are different from fiber Bragg grating (40, 42, 44) to fiber Bragg grating (40, 42, 44) along the at least one fiber core. Also described is an optical system and a method of interrogating an optical fiber sensor.

Abstract: An optical fiber sensor includes optical sensor elements, for instance a plurality of multiplexed Bragg gratings, a broadband optical source, an interferometer with at least one polarization-maintaining fiber section with which a birefringence modulator, a signal generator and a receiver are associated. The optical birefringence in the propagation medium, i.e., in the polarization-maintaining fibre, combined with the birefringence of the birefringence modulator, produce in the interferometer the path difference and thereby the interference fringes which, appropriately processed according to the known technique, allow the measurement to be traced. The use of a birefringence modulator associated with the polarization-maintaining fiber allows a high-speed modulation of the interferometer, thus allowing high sampling rates of the sensor without having variations in responsivity depending on the alignment of the sensors with the interferential fringes of the interferometer.

Abstract: Aspects of the present disclosure describe dynamic road traffic noise mapping using DFOS over a telecommunications network that enables mapping of road traffic-induced noise at any observer location. DFOS is used to obtain instant traffic data including vehicle speed, volume, and vehicle types, based on vibration and acoustic signal along the length of a sensing fiber along with location information. A sound pressure level at a point of interest is determined, and traffic data associated with such point is incorporated into a reference noise emission database and a wave propagation theory for total sound pressure level prediction and mapping. Real-time wind speed using DFOS—such as distributed acoustic sensing (DAS)—is obtained to provide sound pressure adjustment due to the wind speed.

Abstract: A system includes an additive manufacturing machine having a reference surface and an object surface, at least one camera device to capture the reference surface, at least one projector device to project at the reference surface, a memory storing computer-readable instructions, and at least one processor to execute the instructions to move the reference surface above or below a highest point the object surface, and move the reference surface downward and obtain a digital fringe projection phasemap of the reference surface using the at least one camera device and the at least one projector device until a whole measurement volume has phasemap data.

Abstract: Non-destructive testing apparatuses, systems, and methods for assessing strain in structural components are disclosed. Structural components include induced predetermined regions having materials of varying density, including induced geometric patterns of differing densities within the structural component that can be a composite material structural component. The method includes projecting waves of energy, that can be beams of electromagnetic (EM) energy and/or waves of ultrasonic (UT) energy, into or through the structural component to evaluate the predetermined induced pattern region of varying density and determining existing strain within a structural component based on the detected energy response.

Abstract: According to certain embodiments of the disclosure, an electronic device comprising: a support member having a first hole; a first fingerprint sensor disposed in the first hole; and a non-conductive injection molding material integrally joining the support member and the first fingerprint sensor.

Abstract: A monitoring system according to the present disclosure includes an optical fiber (10) laid on a ground or a seabed, an optical fiber sensing unit (21) configured to receive an optical signal from the optical fiber (10) and detect a vibration produced in the ground or the seabed based on the optical signal, and an analyzing unit (22) configured to identify a natural phenomenon that has caused the detected vibration based on a unique pattern of the detected vibration.

Abstract: A fibre-optic measurement system equipped with a controlled light generation system (1) and a receiving system (2) connected via an optical path which comprises a directional device (4) and which, in addition, has a processing unit (9) for controlling the light generation system (1) and for receiving and processing the signal from the receiving system (2), according to the invention, it is characterized by the fact that it has a selective mode device (5) and is adapted to be connected to a fibre-optic telecommunications network by a selective mode device (5) and the processing unit (9) is adapted to implement the OFDR and/or COTDR measurement technique for measuring changes in the optical distance and processing them into one or more parameters. Moreover, the object of the invention is also the method of adaptation of a telecommunications network into a sensor network and a fibre-optic measurement and communication system.

Abstract: An anti-tamper assembly is disclosed for a circuit board which comprises one or more electronic components. The assembly comprises a container having side walls, a first closed end and a second, opposing open end, the container being configured to be mounted on said circuit board at said open end, over at least one of the electronic components to form, in use, a sealed cavity around said at least one of said electronic components. The assembly further comprises a source of radioactive particles mounted within the container, an image sensor for capturing image frames within said sealed cavity, in use.

Abstract: A shape sensing system for an anthropomorphic test device is disclosed that includes a plurality of body parts and at least one optical fiber that has a plurality of cores in a spaced and parallel relationship with one another that extend between ends of the optical fiber for sensing positions of the body parts. Each of the cores have a plurality of grating sensors disposed along a length thereof capable of determining a position and orientation of the body parts.

Abstract: Systems and methods for optical transmission of one-or-more out-of-band signals associated with audio-video signal communication are described. In one aspect, an optical receiver receives a first out-of-band electrical signal and a second out-of-band electrical signal from a video sink. The first out-of-band electrical signal may correspond to an audio-video stream previously received or concurrently being received from a video source optical transmitter at the optical receiver. The second out-of-band electrical signal may also correspond to the audio-video stream. The optical receiver may combine the first out-of-band electrical signal and the second out-of-band electrical signal into a transmit electrical signal. In one aspect, the optical receiver converts the transmit electrical signal into an optical signal, and transmits the optical signal to an optical transmitter via an optical communication channel.

Abstract: An article of manufacture comprising: (a) a body at least a portion of which is a multi-phase material (MPM) defining a traction surface; (b) the MPM comprising at least first and second zones comprising first and second materials, M1, M2, respectively, at or near the traction surface, the M1 and M2 having first and second Young moduli respectively, the first and second moduli differing by at least a factor of 3; and (c) wherein each of the second zones has a center, and wherein the second zones have a center-to-center radial distribution function having a peak at between 10 ?m and 10 mm.

Abstract: A system comprises a teleoperated manipulator, a manually operated instrument, and a position sensor coupled to the manually operated instrument. The position sensor is configured to generate pose information for the manually operated instrument. The system further comprises a controller configured to map a pose of the manipulator to a fixed world reference frame based on three-dimensional pose information for the manipulator known internally within the system. The controller is further configured to map a pose of the manually operated instrument to the fixed world reference frame based on the pose information for the manually operated instrument.

Abstract: A system comprising a generator and a receiver. The generator can be coupled to an optical network. The generator can be configured to generate a plurality of wavelengths of light. The plurality of wavelengths of light can be continuously cycled. The plurality of wavelengths of light can be modulated to encode information onto the plurality of wavelengths of light. The plurality of wavelengths of light can be multiplexed into a multiplexed light signal. The multiplexed light signal can be provided to a first wavelength division multiplexer of the optical network. The receiver can be coupled to the generator and the optical network. The receiver can be configured to receive a demultiplexed wavelength of light from a second wavelength division multiplexer of the optical network. The demultiplexed wavelength of light can be demodulated to decode information encoded onto the demultiplexed wavelength of light. Optical power of the demultiplexed wavelength of light can be measured.

Abstract: The present invention relates to an optical fiber sensor for shape sensing, comprising an optical fiber having embedded therein a number of at least four fiber cores (1 to 6) arranged at a distance from a longitudinal center axis (0) of the optical fiber, the number of fiber cores (1 to 6) including a first subset of at least two fiber cores (1, 3, 5) and a second subset of at least two fiber cores (2, 4, 6), the fiber cores (2, 4, 6) of the second subset being arranged to provide a redundancy in a shape sensing measurement of the fiber sensor (12?). The fiber cores (1, 3, 5) of the first subset are distributed in azimuthal direction around the center axis (0) with respect to one another, and each fiber core (2) of the second subset is arranged in non-equidistantly fashion in azimuthal direction around the center axis (0) with respect to two neighboring fiber cores (1, 3) of the first subset.

Abstract: Channel predictive behavior and fault analysis may be provided. A forward time value may be determined comprising a time a forward signal takes to travel from a transmitter over a channel to the receiver. Next, a reflected time value may be determined comprising a time a reflected signal takes to travel to the receiver. The reflected signal may be associated with the forward signal. A discontinuity may then be determined to exist on the channel based on the forward time value and the reflected time value. The reflected signal may be caused by the discontinuity and a high impedance or low impedance at the transmitter present after the forward signal is sent.

Abstract: In an ingress-protected fiber optic connector assembly, an optical fiber plug mates with a receptacle at a bulkhead adapter and an ingress-protected housing assembly couples to the bulkhead adapter to enclose the optical fiber plug. The ingress-protected housing includes an outer housing and a compressible cable seal. The outer housing is rotatable to advance the outer housing, simultaneously compressing the compressible cable seal and fastening the housing assembly to the bulkhead adapter. The outer housing can have a plurality coupling positions at which the cable seal is compressed with a different amount of compression force. A non-sealing cable clamp can transfer tension on the cable to the bulkhead adapter.

Abstract: A system for monitoring a physical change of a marine structure includes a complex optical measuring instrument configured to detect a behavior and structural change of the marine structure by using at least one optical sensor by means of optical fiber Bragg grating.

Abstract: A medical system includes a probe, an electro-optical measurement unit, and a processor. The probe is configured for insertion into a blood vessel of a brain, and includes two optical fibers, which include each an optical diffuser at distal ends thereof. One fiber is configured to guide an optical signal to a location along the blood vessel and to diffuse the optical signal so as to interact with a brain clot in the blood vessel. The other fiber is configured to collect the diffused optical signal that interacted with the brain clot at another location along the blood vessel. The electro-optical measurement unit is configured to transmit the optical signal to one optical fiber, and to receive and measure the diffused optical signal from the other optical fiber. The processor is configured to identify a composition of the brain clot by analyzing the measured diffused optical signal.

Abstract: A device for measuring a temperature of a molten metal bath, comprising: an optical cored wire; a tube, wherein the optical cored wire is at least partly arranged in the tube, wherein the tube has an outer diameter in the range of 4 mm to 8 mm, and a wall-thickness in the range of 0.2 mm to 0.5 mm; and a plurality of separating elements comprising more than two separating elements arranged in the tube spaced apart from each other, and forming at least one compartment between two of the more than two separating elements. The invention also relates to a system and method for measuring a temperature of a molten metal bath.

Abstract: An optical sensing system including an optical interrogator is operative with an array of reflective sensors, each sensor providing a separable reflected spectral response parameter such as a unique Gaussian standard deviation or reflected response compared to other sensors in the same operating wavelength range. The optical interrogator provides narrowband swept or broadband continuous optical power source to the array of FBG sensors, and an optical interrogator generates a g(x) representation of power vs wavelength of the reflected optical power and decomposes the representation into the wavelength of the individual sensors, thereby allowing operation of two or more FBG sensors in the same operating wavelength range.

Abstract: An electronic device and communication method are disclosed. The electronic device comprises a processing circuit configured to perform a pre-processing operation on a first one-dimensional sequence of modulation symbols, the pre-processing operation including: performing a dimension-increasing conversion to convert the first one-dimensional sequence of modulation symbols into a first multi-dimensional modulation symbol block; transforming the first multi-dimensional modulation symbol block into a second multi-dimensional modulation symbol block with a first transformation, wherein the first transformation couples each symbol in the first multi-dimensional modulation symbol block with each other; and performing a dimension-decreasing conversion to convert the second multi-dimensional modulation symbol block into a second one-dimensional sequence of modulation symbols, wherein the dimension-decreasing conversion is an inverse process of the dimension-increasing conversion.

Abstract: An optical fiber having an axial direction and a cross section perpendicular to the axial direction, and a method and preform for producing such an optical fiber. The optical fiber is adapted to guide light at a wavelength ?, and includes a core region, an inner cladding region surrounding said core region, and at least one of a first type of feature including a void and a surrounding first silica material. The core, the inner cladding region and the first type of feature extends along said axial direction over at least a part of the length of the optical fiber. The first silica material has a first chlorine concentration of about 300 ppm or less.

Abstract: Methods for determining sensor channel location in distributed sensing of fiber-optic cables are disclosed. In one method, three or more Fiber Bragg-Gratings (FBGs) connected in series by a standard telecommunication fiber and interrogated using an input distributed fiber-optic sensing (DFOS) laser, where the input DFOS laser has a single wavelength. The input DFOS laser operates on a single wavelength that is different than the respective wavelengths of each of the three or more FBGs. The three or more FBGs are interrogated using an input broadband FBG laser. Each FBG reflects a wavelength of laser light that is proportional to the grating size, using an optical time domain reflectometer (OTDR) at the FBG wavelength, the distance to the particular FBG in the optical domain is computed and compared to the physical measurement of the FBG location. The sensor channel locations of the DFOS system are calibrated and constrained using this method.

Abstract: Sensing systems include a tube defining a Fabry-Perot cavity and an optical fiber including a distal end disposed within the Fabry-Perot cavity and a proximal end. A corrodible material caps the Fabry-Perot cavity. Devices for sensing corrosion of downhole equipment include an optical fiber with a corrodible material disposed over a distal end of the optical fiber. Systems for sensing a condition in equipment include an optical fiber with a fiber Bragg grating proximate a distal end thereof and a mass of sensor material coupled to the distal end of the optical fiber. The mass of sensor material is suspended from above the fiber Bragg grating. Other systems for sensing a condition in a wellbore include an optical fiber and a plurality of fiber Bragg gratings along a length thereof. A plurality of sensor materials are coupled to the optical fiber and surround respective fiber Bragg gratings.

Abstract: A photonic device includes a semiconductor substrate and a pressure-sensitive membrane. The pressure-sensitive membrane is arranged in or on the substrate. A photonic structure is at least partly coupled to the membrane and arranged to change an optical property depending on a deformation to be induced by a pressure applied to the membrane.

Abstract: A method is disclosed for measuring stress distribution generated on a structural object including two support parts and a beam part provided between the support parts. The method includes: generating first data by sensing, through a first sensing unit, of a moving object or an identification display object attached to the structural object; calculating, based on the first data, a movement duration in which the moving object moves between the support parts; generating, as second data, thermal data by sensing of a surface of the beam part through a second sensing unit; calculating a temperature change amount based on a second data group corresponding to the movement duration; and calculating a stress change amount based on the temperature change amount to calculate stress distribution based on the stress change amount.

Abstract: Disclosed are a system and a method for measuring a magnetorefractive effect of an optical fiber. The system comprises a laser, a coupler A, a sensing optical fiber, a reference optical fiber, a carrier generator, a coupler B, a photoelectric detector and a data acquisition and processing module. The coupler A, the sensing optical fiber, the reference optical fiber and the coupler B form a Mach-Zehnder optical fiber interferometer. An external magnetic field influences the refractive index of the sensing optical fiber, so that the optical path difference between two paths of optical signals in the sensing optical fiber and the reference optical fiber is changed, the intensity of an interference optical signal output by the coupler B is changed, and the refractive index change of the sensing optical fiber under the action of the magnetic field is measured by detecting and processing the interference optical intensity.