Abstract: A downhole valve assembly comprises a sleeve concentric with a housing and movable relative to a port through the housing to control flow of fluid through the port. A sensor assembly provides indicates the relative positions of the sleeve and housing, and comprises first and second sensors on e.g. the housing which detect markers on e.g. the sleeve. The sensor outputs are produced by processing (e.g. combining, integrating, summing, subtracting or otherwise processing) the signal components of each of the first and second sensors to correct for misalignment of the sleeve with the housing. The sensor output provides position information for more than one plane, and the output signal therefore allows for correction of errors in the position information arising from misalignment of the sleeve with the housing.

Abstract: A method of determination of deformation along a first direction of an equipment (1) in contact with hot material and including an inner face (3) in contact with the hot material and an outer face (4) opposite to the inner face (3) is provided. An equipment (1) in contact with hot material provided with means to determine its deformation along a first direction is also provided.

Abstract: An optical fiber interrogator for interrogating optical fiber that includes fiber Bragg gratings (“FBGs”). The interrogator includes a light source operable to emit phase coherent light, amplitude modulation circuitry optically coupled to the light source and operable to generate pulses from the light, and control circuitry communicatively coupled to the amplitude modulation circuitry that is configured to perform a method for interrogating the optical fiber. The method includes generating a pair of light pulses by using the amplitude modulation circuitry to modulate light output by the light source without splitting the light.

Abstract: A distributed acoustic system (DAS) with an interrogator, an umbilical line attached at one end to the interrogator, and a downhole fiber attached to the umbilical line at the end opposite the interrogator. A method for optimizing a sampling frequency may begin with identifying a length of a fiber optic cable connected to an interrogator, identifying one or more regions on the fiber optic cable in which a backscatter is received, and optimizing a sampling frequency of a distributed acoustic system (DAS) by identifying a minimum time interval that is between an emission of a light pulse such that at no point in time the backscatter arrives back at the interrogator that corresponds to more than one spatial location along a sensing portion of the fiber optic cable.

Abstract: A temperature sensor and temperature sensing system for sensing changes in temperature up to a predetermined temperature is disclosed. The temperature sensor includes a microstructured optical fiber where the microstructured optical fiber includes a plurality of longitudinal channels extending along the microstructured optical fiber. The sensor also includes a fiber Bragg grating formed in the microstructured optical, fiber by generating a periodic modulation in the refractive index along a core region of the microstructured optical fiber. The fiber Bragg grating is operable to produce band reflection at a reflection wavelength that varies in accordance with changes in temperature at the core region of the optical fiber.

Abstract: The present invention relates to a static electric induction apparatus (1b) comprising a winding (2) including a plurality of winding units (3), at least one first spacer element (5) arranged between the winding units (3) and including a first groove (18) defined in the surface thereof, and a sensor system for monitoring the temperature in the apparatus, wherein the sensor system comprises an elongated and flexible temperature sensing element (16) disposed in the first groove. The first groove (18) has a curved part that receives the flexible temperature sensing element which is wound at least one revolution in the first groove (18). The first groove enters and exits the first spacer element in one and the same end of the first spacer element. The apparatus comprises an elongated second spacer element (14a) extending in an axial direction on the outside of the winding (2).

Abstract: A fiber-reinforced composite material having a sensor array of a plurality of sensors for structural health monitoring of the composite material, and also having electrical conducting paths incorporated in the composite material and extending through the composite material. The electrical conducting paths are arranged in a first group and in a second group different from the first group, with the first group extending in a first direction, and the second group extending in a second direction and intersecting the electrical conducting path of the first group. The intersecting paths form together with the conducting paths of first group a network of n row conductors and m column conductors. There is also a signal processing means for monitoring at least one electrical characteristic of the conducting paths.

Abstract: A shape calculating apparatus includes a light source and a light guide provided with detection targets to decrease quantity of light guided by the light guide according to a bend shape of the light guide. The apparatus also includes a light detector to detect light quantity information in wavelengths included in light absorption spectra of the detection targets, a calculation unit that makes a calculation relating to a shape of each detection target based on the light quantity information, and a control unit that changes a dynamic range of at least one of an intensity of light input to the light guide and a detection signal output by the light detector for each wavelength range so that a magnitude of the detection signal is within a range between a lower limit threshold and an upper limit threshold of the light detector.

Abstract: Methods and systems for automated health assessment of fiber optic links of a fiber optic communication system are described. Tables are used to describe the fiber optic links, including access addresses to communication modules used in the links. Telemetry data representative of operation of the communication modules can be read via the access addresses into a central station. OTDR/OFDR measurement data of fiber optic segments used in the links can be read via the access addresses into the central station. The telemetry and/or OTDR/OFDR measurement data can be used by the central station for comparison against reference data to assess health of the links. The communication modules locally and continuously capture the telemetry data to detect transient events that may be the result of tampering of the links.

Abstract: The invention relates to a method for detecting a local change in refractive index of a dielectric medium located on the surface of an optical sensor, said optical sensor comprising for this purpose a waveguide comprising a region, called the active region, covered with at least one metallic layer in contact with the dielectric medium, said method comprising the following steps: a) emitting a light beam at the input of the waveguide so that this light beam can be propagated, within the waveguide, according to at least N propagation modes, where N is a natural integer such that N?2; b) measuring the intensity of at least one zone of the spatial distribution of the intensity of the light beam reflected by said active region of the optical sensor; and c) detecting the local change in the refractive index of the dielectric medium by means of a database supplying the link between the intensity of said at least one zone of the spatial distribution of the intensity of the light beam reflected by the active region o

Abstract: A method and system for generating imaging data during a medical intervention are provided. An external optical sensor is attached on the patient's body, and includes at least one external orientation fiber core configured to measure an orientation of the external optical sensor relative to a point of reference. The external optical sensor is interrogated to generate external sensor orientation information during the medical intervention. That information is used to estimate an orientation of the external optical sensor, which is then displayed during the medical intervention.

Abstract: Devices, systems, and methods for flexible, deployable structures with optical fiber are provided in accordance with various embodiments. For example, some embodiments include a system that may include a flexible, deployable structure and one or more optical fibers coupled with the flexible, deployable structure. In some embodiments, one or more conditions of the one or more optical fibers coupled with a flexible, deployable structure may be determined. One or more conditions of the flexible, deployable structure may be determined utilizing the determined one or more conditions of the one or more optical fibers coupled with the flexible, deployable structure. The one or more conditions of the one or more optical fibers may be correlated to the one or more conditions of the flexible, deployable structure.

Abstract: Assessing pipeline integrity includes deploying vibration sensors at optimal sensing locations in the pipeline network. The sensors communicate with an analyzer via an intermediary that is a local or a remote wireless controller. A sensor records and processes vibration signals regularly, according to protocols kept in the memory of the sensor. The sensor, via a controller, communicates recorded data or processed data to an analyzer and receives updated protocols or other instructions from an analyzer. The analyzer aggregates recorded and processed data from the sensors, which are then analyzed to detect or localize leak sounds from the pipeline network. The recorded data from two or more sensors may be time-aligned using synchronization methods.

Abstract: Apparatuses, systems and methods for producing hydrocarbon material from a subterranean formation using a displacement process are disclosed. In one aspect, there is provided a method of controlling hydrocarbon production of hydrocarbon material disposed within a subterranean formation by a displacement process via a plurality of flow communication stations of an injection well. Characteristics of a supplied production-initiating fluid are determined uphole of the flow communication stations for a plurality of states of the injection well, wherein in each of the states of the injection well a different subset of the flow communication stations are disposed in an opened condition and a different subset of the flow communication stations are disposed in a closed condition. Characteristics may be determined at the surface, for example, at the wellhead. A state of the injection well that optimizes one or more operating parameters is determined.

Abstract: Systems and methods are provided for extracting hemodynamic information, optionally employing portable electronic devices with optional User Interface (UI) features for system implementation. The systems and methods may be employed for acquiring hemodynamic signals and associated electrophysiological data and/or analyzing the former or both in combination to yield useful physiological indicia or results. Such hardware and software is advantageously used for non-invasively monitoring cardiac health.

Abstract: Systems, methods, and other implementations described herein relate to a manner of detecting kinking or other bending on a bendable structure. In one implementation, a bendable structure is configured to kink at different locations. First and second sensors surface-mounted antiparallel along the bendable structure have bending responses that increase with increasing amounts of bending, and that are increasingly sensitive along their lengths. The bending responses from first and second sensors are received at a first time and a second time subsequent to the first time. The formation of a kink is identified in response to identifying that the bending responses are indicative of unkinked bending at the first time and indicative of kinked bending at the second time. In response to identifying the formation of the kink, the location of the kink is identified based on the bending responses at the first time.

Abstract: A method and system for monitoring fluid flow in an open channel system, using an optical fibre that extends along at least a portion of the open channel system within the channel below the surface of the fluid. The method comprising sending light pulses into the sensor optical fibre, receiving backscattered light from the sensor optical fibre, and analysing properties of the backscattered light to obtain data representing strain along the sensor fibre. The strain data can be processed to derive information about the fluid flow, such as fluid depth, flow velocity and flow volume. A containment system for the optical fibre sensor may be included to protect the fibre and convert the pressure of a fluid in the open channel to a strain in the fibre. The temperature of the fluid may also be measured and temperature compensation of the measured strain carried out.

Abstract: A system for detecting an intrusion of at least one of a monitoring fiber and a detector comprises a sensor having a closure monitor and an intrusion monitor, the closure monitor including a signal generator and at least one detector attached to the monitoring fiber. The signal generator transmits signal light such that the monitoring fiber receives the transmitted signal light and reflects a portion of the signal light via the at least one detector to the closure monitor and transmits a non-reflected portion of the signal light. The intrusion monitor receives the transmitted non-reflected portion of the signal light, and monitors the non-reflected portion of the signal light to detect transient changes in the non-reflected portion of the signal light indicative of at least one of a vibration, a motion and a handling of at least one of the monitoring fiber and the at least one detector.

Abstract: A system and method for detecting and determining the location of (i) defects in railroad track rails and (ii) the presence of cars, trains or vehicles on the rails. A strain sensitive fiber optic cable is continuously bonded to each section of rail, with the cables of adjacent rails being interconnected by non-strain-sensitive fiber optic cable. A detection system provides an optical backscatter sensing function and an optical time domain reflectometry analysis and distance determining function to determine the nature and location of rail anomalies and vehicle presence on the rails.

Abstract: An approach for curing ultraviolet sensitive polymer materials (e.g., polymer inks, coatings, and adhesives) using ultraviolet radiation is disclosed. The ultraviolet sensitive polymer materials curing can utilize ultraviolet light at different wavelength emissions arranged in a random, mixed or sequential arrangement. In one embodiment, an ultraviolet light C (UV-C) radiation emitter having a set of UV-C sources that emit UV-C radiation at a predetermined UV-C duration and intensity operate in conjunction with an ultraviolet light B (UV-B) radiation emitter having a set of UV-B sources configured to emit UV-B radiation at a predetermined UV-B duration and intensity and/or an ultraviolet light A (UV-A) radiation emitter having a set of UV-A sources configured to emit UV-A radiation at a predetermined UV-A duration and intensity, to cure the ultraviolet sensitive polymer materials.

Abstract: Provided are robotic systems and methods for navigation of luminal network that can improve strain-based shape sensing. In one aspect, the system can compare strain-based shape data to shape data determined based on robotic data (e.g., kinematic model data, torque measurements, mechanical model data, command data, etc.) and adjust the strain-based shape data as necessary. Any portion of the strain-based shape data can be adjusted, weighted differently, or discarded based on the comparison. For example, data from trustworthy sources may indicate that the shape of an instrument exhibits or should exhibit one or more characteristics. If the system determines that any portion of the strain-based shape data is not in agreement with such characteristics, the system may adjust the portion of the strain-based shape data such that the adjusted strain-based shape data is in agreement with the characteristics of the instrument.

Abstract: An interrogation system includes lasers and an optical filtering device. The lasers include a primary set of lasers coupled to a primary multiplexer for generating primary light signals and a secondary set of lasers coupled to a secondary multiplexer for generating secondary light signals. The primary set of lasers may generate light signals having a first set of overlapping wavelengths and the secondary set of lasers may generate light signals having a second set of overlapping wavelengths. The optical filtering device may route the primary light signal and the secondary light signal to an optical fiber sensing cable positioned in a wellbore and receive reflection signals corresponding to the primary light signal and the secondary light signal. The reflection signals corresponding to the secondary light signal may have a first wavelength range that matches a second wavelength range of the primary light signals.

Abstract: An optical fiber distributed acoustic sensor system includes weak broadband reflectors inserted periodically along the fiber. The reflectors reflect only a small proportion of the light from the DAS incident thereon back along the fiber, typically in the region of 0.001% to 0.1%, but preferably around 0.01% reflectivity per reflector. In addition, to allow for temperate compensation to ensure that the same reflectivity is obtained if the temperature changes, the reflection bandwidth is relatively broadband. In some embodiments the reflectors are formed from a series of fiber Bragg gratings, each with a different center reflecting frequency, the reflecting frequencies and bandwidths of the gratings being selected to provide the broadband reflection. A chirped grating may also be used to provide the same effect. In preferred embodiments, the reflectors are spaced at half the gauge length i.e. the desired spatial resolution of the optical fiber DAS.

Abstract: Disclosed is a sensor for detecting temperature of an aircraft. The sensor comprises a temperature sensor elongated with respect to an axis. The temperature sensor comprises a sheath elongated with respect to the axis. The temperature sensor comprises a central conductor disposed within the sheath and elongated with respect to the axis having a conductor material defining a conductor temperature coefficient having a conductor coefficient magnitude. The temperature sensor comprises an optical fiber disposed within the sheath. The temperature sensor comprises a thermistor disposed within the sheath and surrounding the central conductor, the thermistor having thermistor material defining a thermistor temperature coefficient defining a thermistor coefficient magnitude greater than the conductor coefficient magnitude.

Abstract: Embodiments provide an optical transceiver assembly for resolving a problem that an optical assembly has a large size. The optical transceiver assembly may include a first cavity, a second cavity and WDMs. The first cavity may include at least two optical receivers, which may be configured to receive light of different wavelengths, respectively. The second cavity may include at least two optical transmitters, may be configured to emit light of different wavelengths, respectively. Each of the at least two optical receivers and each of the at least two optical transmitters may correspond to different WDMs, respectively. The WDM corresponding to one of the at least wo optical receivers can be configured to: separate, from light emitted from an optical fiber, light of a wavelength receivable by the corresponding optical receiver, transmit the light to the corresponding optical receiver, and reflect the other wavelengths.

Abstract: A vehicle includes a generator, an outlet, and a controller. The generator is electrically connected to the outlet. The controller is programmed to, responsive to outlet temperature being less than a threshold, deliver an electric current from the generator to an external device that is connected to the outlet. The controller is further programmed to, responsive to the outlet temperature exceeding the threshold, inhibit delivering the current from the electric machine to the external device.

Abstract: A system includes a first optical sensor sensitive to both a parameter of interest, Parameter1, and at least one confounding parameter, Parameter2 and a second optical sensor sensitive only to the confounding parameter. Measurement circuitry measures M1 in response to light scattered by the first optical sensor, where M1=value of Parameter1+K*value of Parameter2. The measurement circuitry also measures M2 in response to light scattered by the second optical sensor, where M2=value of Parameter2. Compensation circuitry determines a compensation factor, K, for the confounding parameter based on measurements of M1 and M2 taken over multiple load/unload cycles or over one or more thermal cycles. The compensation factor is used to determine the parameter of interest.

Abstract: Sensing parts are formed in different directions in a circumferential direction in substantially a same position in the longitudinal direction thereof. Each sensing part is configured to include an optical characteristic changing member which generates the optical signals having absorption wavelength characteristic regions that vary from sensing part to sensing part by giving an optical characteristic change, which differs from that of other sensing parts, to the sensor light incident thereon in accordance with an amount of bending in a specific direction. A light detector detects the optical signals included in sensor light from a light source, which has passed through the sensing parts and undergone the optical characteristic change.

Abstract: A sensor arrangement using an optical fiber and methodologies for performing an analysis of a subterranean formation, such as a subterranean formation containing a hydrocarbon based fluid. The sensor arrangement may be used to measure one or more physical parameters, such as temperature and/or pressure, at a multiplicity of locations in the subterranean reservoir. The sensor arrangement may comprise a sensor array comprising an elongated outer casing for insertion in the subterranean formation and into a fluid in the subterranean formation. The sensor array may comprise an optical fiber defining an optical path that links one or more temperature sensors and one or more pressure sensors and transports measurement data generated by the temperature and pressure sensors. A data processing system may be connected to the sensor array to receive measurements from the sensor array and to compute one or more values of a property of an extraction installation operating on the subterranean formation.

Abstract: A method, apparatus, and system for monitoring a vehicle. Optical signals are sent into a fiber optic mesh covering a region of the vehicle. Response optical signals occurring in response to optical signals sent into the fiber optic mesh are detected. Sensor data is generated from the response optical signals detected. A determination is made as to whether a group of nonconformances is present in the vehicle using the sensor data. A group of actions is performed when the group of nonconformances is present.

Abstract: A training or rating system includes a shape sensing enabled device (104) and a database (140) of possible shapes and sequences of shapes for the shape sensing enabled device. The possible shapes and sequences of shapes include a collection of poses derived by appropriately performing a procedure with the shape sensing enabled device. A comparison module (154) is configured to compare real-time poses of the shape sensing enabled device with the collection of poses in the database to output comparison feedback for a user of the shape sensing enabled device.

Abstract: A temperature measurement device includes: a light source configured to input a light into an optical fiber; a detector configured to detect a Stokes component and an anti-Stokes component from a back scattering light from the optical fiber; a memory; and a processor configured to execute a process, the process comprising: in a predetermined region including a sample point of the optical fiber, calculating a range including the sample point in accordance with a largeness of a correlation between the Stokes component and the anti-Stokes component; smoothing the Stokes component and the anti-Stokes component in the range; and measuring a temperature of the sample point with use of the Stokes component and the anti-Stokes component that are smoothed by the corrector.

Abstract: Apparatuses relate generally to a fiber optic cable. In such an apparatus, a housing has a channel or bore for receipt of a portion of the fiber optic cable having a fiber optic sensor. An acoustic interface layer is coupled to a surface of the housing to reduce stress wave coupling loss at an interface between the fiber optic sensor and a host structure surface. In another such apparatus, a patch structure is for a fiber optic cable coupled to a fiber optic voltage conditioner. In yet another such apparatus, a fiber optic voltage conditioner is coupled for optical communication to a fiber optic cable having a Fiber Bragg Grating sensor. The fiber optic voltage conditioner includes a tunable light source having a broadband light source or a gain medium configured to provide a narrowband light signal from a broadband light signal for providing to the fiber optic cable.

Abstract: Pressure sensing having 2-D resolution is provided by an array of optical waveguides having wave-guide intersections (e.g., intersecting rows and columns). Pressure induced cross-coupling between intersecting wave-guides is enhanced by including mechanical structures at each intersection that enhance local waveguide bending. For example, such structures can be rigid rings around the wave-guide intersections.

Abstract: An optical fiber flow sensor, including: a housing, an elastic component, an optical fiber detection component, a floating element, and a fixed sealing joint. The elastic component includes a first and second elastic members that are symmetrical and are disposed in a closely fitted manner, with fitting surfaces of the first and the second elastic members being respectively provided with a corresponding seating groove. The optical fiber detection component is disposed in the seating grooves, and both ends of the optical fiber detection component are welded in the seating grooves via a glass solder. The elastic component is enclosed in the housing, and one end of the housing is fixed at the fixed sealing joint. The optical fiber detection component is sealed within the elastic component so as to avoid direct contact with an external fluid, and prevent damage by corrosion, hydrogen loss, or the like.

Abstract: A sensor for detecting micro-movements is provided herein. In various embodiments, the sensor includes a looped structure formed of a continuous multi-mode optical fiber arranged into a plurality of loops disposed substantially in a plane. Each loop within the looped structure is partially overlapping yet laterally offset from neighboring loops. The sensor further includes a light source coupled to a first end of the looped structure, a receiver coupled to a second end of the looped structure, and one or more control and processing modules. Related methods of manufacture and use are also disclosed.

Abstract: A measurement device may include a bias source to provide a bias, a photodiode to provide a linear current based on an input optical power and the bias, a log amplifier to receive the linear current and to provide a voltage, and one or more processors to receive the voltage and to determine a measurement of the input optical power at an observed temperature. The measurement may be determined based on a photodiode current corresponding to the voltage, a dark current, and a calibration current. The calibration current may be determined, for a threshold power range, based on a first plurality of current measurements at a first temperature and at a plurality of optical powers, a second current measurement at a second temperature and at a first optical power, and a third current measurement at the second temperature and at a second optical power.

Abstract: A cable is provided for detecting tampering thereof. The cable has at least two copper signal cables, at least one hollow buffer tubes located abutting the two copper signal cables, an inner jacket, an armor, and at least one loose tube optical fiber sensor element disposed within the cable in a configuration that subjects the optical fiber sensor to external conditions. The at least one loose tube optical fiber sensor element is located between and abutting at least one of the copper signal cables and the at least one adjacent hollow buffer tube. The at least one loose tube optical fiber sensor element is configured attenuate under changes in the external conditions.

Abstract: A system and method are used for an optical fiber having a core multiple, closely spaced optical gratings written along the core that create a repeated pattern in the core. A memory stores predetermined reference reflection data and measurement reflection data determined for a length of the core detected from interferometric patterns corresponding to scatter reflections received from the core. Data processing circuitry reduces or removes from the measurement reflection data information that corresponds to reflections due to the repeated pattern in the core to produce filtered measurement data. One or more portions of the filtered measurement data is/are correlated with one or more portions of the reference reflection data to produce multiple correlation values. The greatest of the multiple correlation values is determined, and a location along the fiber corresponding to the greatest correlation value is identified.

Abstract: Embodiments of the subject invention relate to a method and apparatus for infrared (IR) detection. Organic layers can be utilized to produce a phototransistor for the detection of IR radiation. The wavelength range of the IR detector can be modified by incorporating materials sensitive to photons of different wavelengths. Quantum dots of materials sensitive to photons of different wavelengths than the host organic material of the absorbing layer of the phototransistor can be incorporated into the absorbing layer so as to enhance the absorption of photons having wavelengths associated with the material of the quantum dots. A photoconductor structure can be used instead of a phototransistor. The photoconductor can incorporate PbSe or PbS quantum dots. The photoconductor can incorporate organic materials and part of an OLED structure. A detected IR image can be displayed to a user. Organic materials can be used to create an organic light-emitting device.

Abstract: A system includes at least one optical fiber having at least one FBG and a detection system. The optical fiber is configured to be coupled to a structure in at least one location. The location at which the optical fiber is to be coupled to the structure is different from a location at which the FBG is disposed. The detection system includes a light source configured to inject light into the optical fiber, a photodetector configured to detect a shift in a wavelength spectrum of light reflected by the FBG as a result of a time-varying strain induced at the at least one FBG, and a processor configured to detect a shear-horizontal guided stress wave propagating in said structure based on the shift in the wavelength spectrum detected by the photodetector induced by a longitudinal-type guided stress wave that is propagated along the optical fiber.

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: The present invention relates to an optical fiber and a device including the optical fiber. The optical fiber is an optical fiber (1) functionalized with at least one particle (1) of a polymeric gel comprising at least one photosensitive molecule (7) and at least one biomolecule (6), wherein the at least one particle (2) of the polymeric gel is covalently bound to said optical fiber (1).

Abstract: A current conduction element includes an electrical conductor and an insulation of the electrical conductor. The insulation includes a light waveguiding unit. Furthermore, a system and method for insulation monitoring are described.

Abstract: A curvature sensor includes a light source, a flexible light guide including cores, and FBG sensors that are provided in the cores and constitute FBG sensor groups at predetermined positions at predetermined positions along longitudinal axes of the cores. The curvature sensor includes a detector that detects an optical spectrum of light from the FBG sensors, and a processor that obtains a bend of the light guide. FBG sensors provided in a core include a first FBG sensor and a second FBG sensor next to it. The first and second FBG sensors include gratings having first and second pitches. The first pitch is shorter than the second pitch and is closer to the second pitch than other pitches of gratings of all FBG sensors that are provided in the core and include gratings having pitches shorter than the second pitch.

Abstract: Object is to enable a directly-modulated semiconductor laser to be applied as a light source of probe light. A transmission unit configured to generate probe light; and a reception unit including a receiver-side optical bandpass filter that extracts a Stokes component of Brillouin backscattered light from backscattered light which is caused by the probe light in a measurement target optical fiber, and a self-delayed heterodyne interferometer that detects a change in a frequency shift amount of the Stokes component as a phase difference are included. The transmission unit includes a directly-modulated light source configured to generate an optical pulse, and a transmitter-side optical bandpass filter provided in a stage following the directly-modulated light source, and configured to transmit wavelength of an ON level of the optical pulse as the probe light, and block wavelength of an OFF level.

Abstract: Disclosed in some examples are methods, systems, and machine readable mediums for assessing the accuracy of one or more local sensors on a mobile device (such as an AV). In some examples, the accuracy of a local sensor of a first AV may be assessed by periodically comparing sensor readings collected by the local sensor to sensor readings matching selection criteria that are collected by one or more remote sensors located at one or more other nearby AVs. A sensor that reports data that is signifimaytly different from that reported by neighboring AVs is likely to be malfunctioning. The use of nearby sensors in nearby AVs may provide for a method for ensuring the integrity of the AV sensor readings without adding redundant sensors.

Abstract: Overheat and fire detection for aircraft systems includes an optical controller and a fiber optic loop extending from the optical controller. The fiber optic loop extends through one or more zones of the aircraft. An optical signal is transmitted through the fiber optic loop from the optical controller and is also received back at the optical controller. The optical controller analyzes the optical signal to determine the temperature, strain, or both experienced within the zones.

Abstract: A method for identifying a proximal object, including providing light emitters, light detectors and lenses, mounted in a housing, each lens, denoted L, being positioned in relation to a respective one of the detectors, denoted D, such that light entering lens L is maximally detected at detector D when the light enters lens L at an angle of incidence ?, activating the detectors synchronously with activation of each emitter to measure reflections of the light beams emitted by each emitter, and calculating a location of a reflective object along a path of a light beam projected by an activated emitter, by calculating an axis of symmetry with respect to which the outputs of the synchronously activated detectors are approximately symmetric, orienting the calculated axis of symmetry by the angle ?, and locating a point of intersection of the path of the emitted light beam with the oriented axis of symmetry.

Abstract: A packaged fiber laser may include a wound fiber laser spiral including a metal ribbon having ends, surfaces, and edges; a fiber laser on a first one of the surfaces of the metal ribbon; and a metal sheet coupled to a first one of the edges of the metal ribbon or a second one of the surfaces of the metal ribbon. Packaging for a fiber laser may include a cooling plate coupled to a second one of the edges of the metal ribbon or the second surface of the metal ribbon, the cooling plate including: a casing including a cover, a bottom, and an outer sidewall; flow channels formed inside the casing, the flow channels defined by inner sidewalls of the cooling plate, wherein the cover is coupled to a top of the inner sidewalls to enclose the flow channel; and an inlet to deliver coolant to the flow channels.