Abstract: Quantifying a refractive index of a test medium by obtaining spectral data representative for an optical signal being modulated with an optical transfer characteristics of a photonic sensor, the modulation being obtained by combining modulation of a first electromagnetic wave component in an optical filter element with a first periodic transfer spectrum having a first free spectral range and modulation of a second electromagnetic wave component in an optical filter element with a second periodic transfer spectrum having a second free spectral range being different from the first free spectral range. A relative is change induced in the second periodic transfer spectrum by bringing the test medium in proximity with the optical filter element with the second periodic transfer spectrum. The refractive index of the test medium is quantified by determining a wavelength offset of an envelope signal in said spectral data.

Abstract: A chemical sensor is provided. The sensor includes at least one lightguiding element having an optical core. The lightguiding element comprises a layer of graphene situated in sufficient proximity to the core to exhibit evanescent wave absorption of optical energy in at least one optical mode guided in the core.

Abstract: An optical sensor module is proposed. The optical sensor module comprises two parts, including optical module and vibration sensing unit. The vibration sensing unit is disposed on the optical module. The optical module comprises a light source, a photo detector, and a second substrate with optical micro-reflection surface. The vibration sensing unit comprises a first substrate, a membrane, and an optical gate. The membrane is disposed between the first substrate and the optical gate.

Abstract: A particle detection system is provided. The particle detection system includes at least one tapered optical fiber, a light source configured to transmit light through the at least one tapered optical fiber, a photodetector configured to measure a characteristic of the light being transmitted through the at least one optical fiber, and a computing device coupled to the photodetector and configured to determine whether a nanoparticle is present within an evanescent field of the at least one tapered optical fiber based on the measured light characteristic.

Abstract: A light guide sensor includes a light source, a light guide member comprising a core which guides light radiated from the light source, a cladding formed around the core, and at least one detecting portion is formed, and a light receiving unit which receives the light that has been guided by the member and has passed via the detecting portion. The detecting portion includes a first opening formed by removal in the outer circumference of the member so that at least part of the cladding is left by a thickness such as not to transmit the light from the core, and a second opening formed within the range of the first opening to transmit the light from the core. A method of forming such a light guide sensor is provided.

Abstract: A monitor-light-emitting device and multiple light-emitting devices are mounted on a board, and a light-guiding member is disposed in front of these devices. Monitor light emitted from the monitor-light-emitting device is directly supplied to a light receiving device. Part of light emitted from the multiple light-emitting devices is incident on the light-guiding member and is used as reference light. The reference light is received by the light receiving device. Reflected detection light that has been reflected off a target object located in front of the optical sensor is transmitted through the light-guiding member and is received by the light receiving device. A condenser is disposed in front of the light receiving device and the reference light or the reflected detection light is efficiently supplied to the light receiving device.

Abstract: A radiation passing layer has a top surface and a bottom surface below which a proximity sensor is positioned. A visible light opaque layer covers the bottom surface of the radiation passing layer except for an opening therein that allows radiation from the emitter to pass, and scattered radiation to pass to the detector. A radiation shield is between the emitter and the detector, and extends to the bottom of the radiation passing layer. A cold mirror is between the shield and the bottom surface of the radiation passing layer, covering the opening in the opaque layer. A radiation absorber being a separate piece and a different material than the shield provides a radiation seal between the top surface of the shield and the bottom surface of the cold mirror. Other embodiments are also described and claimed.

Abstract: A sensing apparatus includes: a broadband optical source; a first pseudorandom number generator generating a first pseudorandom number code string to modulate the broadband optical source; at least one sensor reflecting an output of the first pseudorandom number generator at a wavelength corresponding to a center wavelength thereof when the output of the first pseudorandom number generator is inputted; a wavelength-time converter converting an output of the sensor by wavelength-time conversion; a second pseudorandom number generator generating a second pseudorandom number code string which is different in frequency from and is the same in bit length and code string as the first pseudorandom number code string; a mixer mixing an output signal of the wavelength-time converter with an output signal of the second pseudorandom number generator; and an integrator integrating an output of the mixer.

Abstract: A light guide member for an object detection apparatus is devised. The object detection apparatus includes a light source unit, and a detection unit for detecting an object adhered on a surface of a light translucent member based on change of light quantity of reflection light received from the light translucent member. The light guide member includes an incident face where the light exiting from the light source unit enters; a detection face where the exiting light exits to a rear face of the light translucent member and the reflection light reflected from the light translucent member enters; an exiting face where the reflection light exits to the detection unit; and a light guiding portion through which the exiting light and the reflection light proceed. The detection face has curvature corresponding to curvature of the light translucent member.

Abstract: A light guide member for an object detection apparatus for detecting an object adhered on a light translucent member based on change of quantity of reflection light received from the light translucent member includes a detection face where light exits to the light translucent member and reflection light reflected from the light translucent member enters, the detection face including a detection area where a part of the reflection light to enter the detection unit passes through, and a non-detection area where remaining part of the reflection light not to enter the detection unit passes through; a first intervening member disposed on the detection face attachable to the light translucent member via the first intervening member; and a second intervening member disposed on the detection face attachable to the light translucent member via the second intervening member. The first intervening member has flexibility greater than flexibility of the second intervening member.

Abstract: The disclosure relates to a light out-coupling arrangement for a touch sensitive system comprising a light guide of a material with a refractive index ng and a top surface configured to be exposed to ambient light, and a bottom surface. The out-coupling arrangement comprises at least one detector arranged along the periphery of the light guide and configured to receive the light propagating in the light guide and an optical filter provided between the light guide and the at least one detector. The optical filter has a first side and a second side where the first side is arranged to face the at least one detector, and the second side is arranged to receive light from the light guide.

Abstract: The present disclosure describes an apparatus including a composite panel. The apparatus includes a first composite panel including a first optical fiber embedded therein, the first optical fiber being arranged in a pattern, and a first input port connected to a first end of the first optical fiber, the first input port configured to receive an optical signal from an optical time domain reflectometer. The optical time domain reflectometer is configured to send the optical signal through the first input port and measure a strength of a reflected optical signal that is reflected back from the first optical fiber, wherein the strength indicates a measured optical impedance of the first optical fiber. A measured optical impedance that is substantially the same as a baseline optical impedance for the fiber indicates no damage, while a measured optical impedance that differs from the baseline optical impedance by a predetermined threshold indicates damage.

Abstract: A shape-sensing segment traverses through at least a portion of a kinematic chain of a tele-operated slave surgical instrument in a tele-operated minimally-invasive surgical system. The shape-sensing segment includes a pre-set perturbation. Shape information from the pre-set perturbation allows determination of relative partial-pose information for at least one link in the kinematic chain.

Abstract: Described are methods for multi-wavelength cavity ring-down spectroscopy; comprising simultaneously and continuously irradiating an optical cavity with light at two or more different wavelengths, each light being intensity-modulated at a different modulation frequency, detecting the light of two or more wavelengths after the light has traveled through the optical cavity; measuring an optical loss of each detected light; and determining a characteristic of the optical cavity from the optical loss of each detected light. Also described are apparatus and systems for multi-wavelength cavity ring-down spectroscopy.

Abstract: The invention concerns a device (100) for the detection and/or quantitative analysis of hydrogen, intended for monitoring an installation (1). Said device (100) comprises a first measuring optical fibre (10) intended to equip the installation (1), and an optical system (20) optically connected to the first measuring optical fibre (10) and adapted to measure the variation in at least one parameter of the first measuring optical fibre (10). The optical system (20) is adapted to measure the parameter along the first optical fibre (10) according to the principle of Brillouin measurement. The invention also concerns a method using such a device (100).

Abstract: A balanced optical cross correlator includes an optical waveguide, a first photodiode including a first n-type semiconductor and a first p-type semiconductor positioned about the optical waveguide on a first side of the optical waveguide's point of symmetry, and a second photodiode including a second n-type semiconductor and a second p-type semiconductor positioned about the optical waveguide on a second side of the optical waveguide's point of symmetry. A balanced receiver including first and second inputs is configured to produce an output current or voltage that reflects a difference in currents or voltages, originating from the first and the second photodiodes of the balanced cross correlator and fed to the first input and to the second input of the balanced receiver.

Abstract: A vortex flowmeter having a measuring tube through which a medium can flow, a bluff body in the measuring tube and a pressure sensor in the effective range of the bluff body. The pressure sensor has a deflectable measuring diaphragm for determining the pressure in the medium neighboring the measuring diaphragm, at least one optical fiber being arranged on and/or in the measuring diaphragm for detecting the deflection of the measuring diaphragm. The optical fiber is at least partially effectively connected to the measuring diaphragm along its length so that a deflection of the measuring diaphragm caused by the medium pressure leads to an extension and/or compression of the optical fiber. The pressure sensor has a pocket that can be deflected by the pressure of the medium and which surrounds the measuring diaphragm and optical fiber to protect them from the medium. The measuring diaphragm is deflected with the pocket.

Abstract: An optical sensor includes a light source, a characteristic light-guiding member, a characteristic changing part which changes the optical characteristic of light, and a detecting unit which detects the light having the optical characteristic changed by the characteristic changing part and guided by the characteristic light-guiding member. The optical sensor includes a control member which inhibits at least the twisting of the characteristic light-guiding member, and controls a bending state of the characteristic light-guiding member, and a positioning mechanism which positions the characteristic changing part with respect to at least a circumferential direction of the characteristic light-guiding member.

Abstract: An optical fluorescence-based sensor comprising at least one sensing element is disclosed. In one aspect, the at least one sensing element comprises a waveguide comprising a waveguide core, a light source optically coupled to an input part of the waveguide core, and a photodetector optically coupled to an output part of the waveguide core, the waveguide core being made of a material comprising a mixture of an optical material and a fluorescent dye.

Abstract: An uncoated polymer optical fiber (POF) that is sensitive to a chemical (e.g. water) and is used to generate a detectable change in its optical properties for the purpose of detecting that chemical when it is dissolved in liquid fuel. The presence of the chemical directly affects the optical properties of the optical fiber. The POF may be made of water-permeable plastic material and may have a grating section comprising a periodic refractive index modulation that exhibits a characteristic reflection or transmission profile to be monitored by a detector. The water-permeability of the constituent material of the POF permits diffusion of water into the fiber, thereby affecting its refractive index or geometry and hence altering the characteristic reflection or transmission profile of the grating section.

Abstract: The invention refers to a device and method for measurement of the distribution of physical magnitudes in an optical fiber, said device comprising and optical source (1) configured for generating a pulsed pump optical signal (A) and a probe optical signal (B) which comprises at least two spectral components separated in optical frequency; a photoreceiver (7) configured to detect the output optical signal (D) as a result of the generation of an RF signal (E), resulting from the beat between the spectral components contained in said output optical signal (D) exiting from the fiber (5); and a demodulator (8) configured to demodulate the RF electrical signal (E) exiting from the receiver (7).

Abstract: Provided is a fiber-optic sensor device. The fiber-optic sensor device is capable of sensing a change in physical quantity by using two fiber Bragg grating units arranged within an optical fiber and a fiber-optic sensor unit arranged therebetween, thereby implementing a low cost fiber-optic grating sensor having a simple structure without requiring a reference FBG.

Abstract: An optical position detection device includes a light receiving section receiving detection light reflected from a target object located in a detectable space through which detection light is radially emitted along an XY plane. The light receiving section includes a light receiving element and a concave mirror. A first cross section (XY cross section) of the reflective surface of the concave mirror is an arc, and a second cross section (YZ cross section) perpendicular to the first cross section is a quadratic curve. Therefore, in the in-plane direction of the XY plane, even light incident from an oblique direction with respect to the light receiving section is reflected by the concave mirror to the light receiving element. In the in-plane direction of the YZ plane, however, the range where the light reaches the light receiving element is limited via the concave mirror.

Abstract: An optical fiber having at least one fiduciary mark is provided. The at least one fiduciary mark is located at one or more axial positions along the optical fiber. The at least one fiduciary mark is configured to produce at least one change in a Rayleigh backscattering signal in the optical fiber. The at least one change in a Rayleigh backscattering signal may be an abrupt change in the Rayleigh backscattering signal. The abrupt change in the Rayleigh backscattering signal occurs over a length of the optical fiber that is of the order of or less than a spatial resolution of an interrogation system employed to detect the Rayleigh backscattering signal.

Abstract: A proximity sensor for detecting non-contact detection of a target using a fibre optic strain sensor and a system for operating multiple such proximity sensors is disclosed. The proximity sensor includes an optic fibre that has an optic fibre strain sensor that is coupled to a mass that moves in response to the target. The mass can be a magnet that moves when a ferrous target is within the magnetic field of the magnet causing the magnet to move and apply strain to the optic fibre strain sensor. The optic strain sensor can include periodic variation in the refractive index of the optic fibre, such as a fibre Bragg grating. The proximity sensor can include a second fibre optic sensor that is sensitive to temperature or a second fibre optic strain sensor coupled to a second magnet that operates in opposition to the first magnet. A system coupling multiple proximity sensors can include an interrogator that has an optical power source and a detector, each coupled to a processor.

Abstract: A device for analyzing a fluid by evanescence field spectroscopy. The device includes a waveguide, a source of electromagnetic radiation coupled to the waveguide on the entry side, and a detector coupled to the waveguide on the exit side for detecting electromagnetic radiation, wherein the waveguide is arranged in contact with the fluid in at least certain sections between its entry side and its exit side. An electrode arrangement is also provided, which is designed to generate an inhomogeneous electric field in the direct environment of the waveguide, said field exerting a dielectrophoretic force on polarisable particles in the fluid, which moves these particles towards or away from the waveguide. A corresponding method is presented.

Abstract: An optical sensor includes a light source, a light supply light guide member optically coupled to the light source, detection light guide members, a light distribution unit to distribute light from the light supply light guide member to the detection light guide members, and a light separating detector to separate and detect the light guided by the detection light guide members. Each of the detection light guide members includes a characteristic detection portion whose optical characteristics vary in accordance with a physicochemical state.

Abstract: An optical sensor (10) comprises an optical cavity defined by a dielectric body and responsive to one or more physical environmental conditions, and a waveguide (70) having a terminal end spaced apart from the optical cavity such that light is optically coupled from the terminal end of the waveguide (70) to the optical cavity. The waveguide (70) is arranged such that, in use, it is maintained at a first temperature that would not damage the optical coupling to the optical cavity when the dielectric body is maintained at a second temperature sufficient to damage the optical coupling to the optical cavity.

Abstract: A fiber fuse detecting apparatus provides early detection of a fiber fuse generation in an optical fiber that propagates laser light, preventing the damage from expanding. It comprises light input means arranged on a laser light incidence side of the optical fiber that inputs at least a portion of reverse direction propagation light propagating in a reverse direction to light incidenting the optical fiber, light receiving means that photo-electrically converts light input by the light input means, electric filter means that extracts from an output signal of the light receiving means a prescribed frequency band component that contains a periodic signal due to fiber fuse, detecting means that detects change of or a prescribed value in output level of the electric filter means, and warning means that emits a warning signal in response to a detection output of the detecting means. The laser light to the optical fiber is stopped or reduced by means of the warning means.

Abstract: A system that provides detection, annunciation, mitigation, and alleviation of stress attacks by executing algorithms based on measurement of intensity of light. The system determines to execute algorithms to take programmed action based on potential effects of a detected stress attack. The system can be used, for example, to determine the position of potential attacks to conduits that transport electricity, oil, gas, foodstuffs, water, people, and materials.

Abstract: A sensor includes: a light emitting part that emits light; a light receiving part that receives reflected light, which is emitted from the light emitting part, is reflected, and returns; and plural arranged fiber bodies that are disposed on a front side of at least one of the light emitting part and the light receiving part and operate as a filter limiting an emission angle or a light receiving angle.

Abstract: An optical device includes at least one optical waveguide including a plurality of elongate portions. Light propagates sequentially and generally along the elongate portions. At least two elongate portions of the plurality of elongate portions are generally planar with one another and are adjacent and generally parallel to one another. The at least two elongate portions are optically coupled to one another such that the light is coupled between the at least two elongate portions in a direction generally perpendicular to the at least two elongate portions as the light propagates generally along the at least two elongate portions.

Abstract: Plasmons on a waveguide may deliver energy to photocatalyze a reaction. The waveguide or other energy carrier may be configured to carry electromagnetic energy and generate plasmon energy at one or more locations proximate to the waveguide, where the plasmon energy may react chemically with a medium or interaction material.

Abstract: An apparatus for detecting deformation of an elongate body may comprise a light source configured to sequentially provide light of multiple frequencies, an optical receiver configured to receive light from the light source, and a filter disposed between the light source and the optical detector. The filter may comprise multiple segments, each of the segments configured to filter light at one of the frequencies so as to alter the amount of light incident on said optical receiver. A total amount of light detected by the optical receiver may change during the sequence so as to be indicative of deformation of the elongate body.

Abstract: This disclosure provides implementations of systems, devices, components, methods, and techniques for producing an optical sensing interface capable of detecting touches or gestures. In one aspect, an apparatus includes a light source, a photo-detector, and a substrate. The apparatus includes an emitting waveguide that extends at least partially over the substrate and that is configured to propagate light from the light source to one or more corresponding emitting portions. Each emitting portion is capable of emitting at least a portion of the light outwards from a plane defining the substrate. The apparatus further includes a sensing waveguide that extends at least partially over the substrate and that includes one or more sensing portions. Each sensing portion is arranged proximate an emitting portion and is capable of receiving light scattered by an object over the corresponding emitting portion. The sensing waveguide is configured to propagate the received light to the photo-detector.

Abstract: Influence of external light is suppressed. With a photodetector including a photodetector circuit which generates a data signal in accordance with illuminance of incident light and a light unit which overlaps with the photodetector circuit, a first data signal is generated by the photodetector circuit when the light unit is in an ON state, a second data signal is formed by the photodetector circuit when the light unit is in an OFF state, and the first data signal and the second data signal are compared, so that a difference data signal that is data of a difference between the two compared data signals is generated.

Abstract: A fiber optic accelerometer has a hollow body that supports an optical fiber therein so as to form a cantilever section, a fiber optic splitter coupled to a first end of the optical fiber and a light source for directing light into the optical fiber via a first branch of the optical splitter. A photo detector receives light conveyed through the optical fiber via a second branch of the optical splitter and measures an intensity of the received light. A reflective target supported at a second end of the hollow body is axially aligned with the second end of the optical fiber in the absence of force. Upon acceleration the cantilever section moves such that its position relative to the reflective target changes thereby reducing the instantaneous intensity of light reflected by the target into the second end of the optical fiber and measured by the photo detector.

Abstract: An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; and at least one amplifier associated with each optical receiver. The interrogator also includes an analog integrator following the at least one amplifier.

Abstract: A method is provided for detecting an orientation of an optical fiber including a flat surface as a part of a surface of the maintaining member. The method includes directing collimated light to the optical fiber through the flat surface of the maintaining member, receiving reflected light of the collimated light by using an optical sensor device, generating a brightness distribution image according to an output signal from the optical sensor device, identifying a reference point on a brightness distribution line appearing on the generated brightness distribution image, according to a position of the brightness distribution line in relation to a target orientation for the optical fiber, the brightness distribution line detectable on the brightness distribution image in correspondence to the reflected light received by the optical sensor device, and detecting the orientation of the optical fiber according to a coordinate of the reference point on the brightness distribution image.

Abstract: A method includes applying pulsed light to a first end of an optical fiber from an optical fault locator during a first distance test. The method includes determining an estimated distance to a fault based on the pulsed light. The method includes sending information indicative of the estimated distance to a remote device. The method also includes applying first visible light from the optical fault locator to the first end of the optical fiber to facilitate identification of the fault at a first site that is remote from the first end of the optical fiber.

Abstract: Systems and methods for sensing properties of a workpiece and embedding a photonic sensor in metal are disclosed herein. In some embodiments, systems for sensing properties of a workpiece include an optical input, a photonic device, an optical detector, and a digital processing device. The optical input provides an optical signal at an output of the optical input. The photonic device is coupled to the workpiece and to the output of the optical input. The photonic device generates an output signal in response to the optical signal, wherein at least one of an intensity of the output signal and a wavelength of the output signal depends on at least one of thermal characteristics and mechanical characteristics of the workpiece. The optical detector receives the output signal from the photonic device and is configured to generate a corresponding electronic signal.

Abstract: An optical fiber may be constructed of a material having at least first and second constituents. The constituents and their relative abundance are selected such that the aggregate Brillouin frequency-shift response exhibited by a fiber constructed using the combined material is insensitive to a selected physical condition, such as temperature or strain, or the sensitivity is below an acceptable application-specific level, over an acceptable range of conditions. The constituents are selected such that the slopes or derivatives of the Brillouin frequency-shift response (with respect to the selected physical condition) of two of the constituents have opposite signs, and are combined in proper quantities such that the constituents balance each other to reduce the slope or derivative of the aggregate Brillouin frequency-shift response of the combined material to zero, or to an acceptable application-specific level, over an acceptable range of conditions.

Abstract: An optical fluid flow sensor and methods are presented. An optical fiber bends in response to a fluid flow, and a light source coupled to the optical fiber transmits light to the optical fiber. Optical sensors surrounding a portion of the optical fiber receive a received light from the optical fiber, and a signal processor module estimates a fluid flow velocity of the fluid flow based on the received light.

Abstract: A system and method of detecting damage to a wind turbine blade uses one or more fluorescent optical fibres comprising a fluorescent material having an excitation wavelength that is selected such that the material fluoresces upon exposure to ambient radiation at the wind turbine blade, wherein the one or more optical fibres are operatively mounted within the wind turbine blade such that upon damage to the wind turbine blade at least a part of the optical fibre is exposed at the surface of the blade causing the optical fibre to fluoresce; a light detector for receiving a light signal from one or from both ends of the one or more optical fibres upon excitation of the fluorescent material and outputting a signal based on the light signal; and a controller coupled to the light detector to receive the signal.

Abstract: Apparatus and techniques for measuring seismic parameters, such as ground force, of a seismic vibrator used for generating seismic signals through a geological formation are provided. The seismic vibrator has a base plate positionable adjacent a ground surface of the geological formation. A sensor pad may be provided with an optical cable positionable between the base plate of the seismic vibrator and the ground surface of the geological formation, a laser for passing a light through the optical cable, and a detector for detecting disturbances in the laser light whereby a ground force applied to the ground surface may be determined.

Abstract: An apparatus for optical signal detection may include a housing in which a channel may be defined to receive an optical fiber in a bent configuration. The channel may have a predetermined radius of curvature to cause optical energy to escape from the fiber when an optical signal is being conveyed in the fiber and be detected at a photodetector arranged at the predetermined radius of curvature.

Abstract: The present disclosure provides an optical device comprising a first optical fiber portion having a first region and further regions between which the first region is positioned. The optical device also comprises a second optical fiber portion having a second region and further regions between which the second region is positioned. Further, the optical fiber comprises at least one member to which the first and second optical fiber portions are attached at the first and second regions. The first and second regions are positioned at opposite sides of an area defined between the first and second regions and spaced apart from each other by a first distance and wherein adjacent further regions are spaced apart by a second distance that is smaller than the first distance.

Abstract: A system and method for monitoring a structure and for distinguishing between an alarm condition, and a nuisance event such as rain. An optical fibre sensor (20,22) produces a signal indicative of a disturbance and level crossing rates are determined to distinguish between noise in the signal (nuisance event) and a required event. A FFT technique is also disclosed as well as classification of an event by extracting predetermined features from the signal.

Abstract: The invention provides a method of obtaining the FBG data in final form (transforming the raw data into frequency and location data) by taking the raw FBG sensor data and dividing the data into a plurality of segments over time. By transforming the raw data into a plurality of smaller segments, processing time is significantly decreased. Also, by defining the segments over time, only one processing step is required. By employing this method, the refresh rate of FBG sensor systems can be improved from about 1 scan per second to over 20 scans per second.

Abstract: Methods and systems for a label-free on-chip optical absorption spectrometer consisting of a photonic crystal slot waveguide are disclosed. The invention comprises an on-chip integrated optical absorption spectroscopy device that combines the slow light effect in photonic crystal waveguide and optical field enhancement in a slot waveguide and enables detection and identification of multiple analytes to be performed simultaneously using optical absorption techniques leading to a device for chemical and biological sensing, trace detection, and identification via unique analyte absorption spectral signatures. Other embodiments are described and claimed.