Abstract: A dynamic polarization controller (“DPC”) that and method of dynamic polarization control useful in optical networks is disclosed. The DPC of the present invention has a polymeric optical waveguide formed on a substrate, such as a silicon wafer. An intermediate portion of the waveguide is suspended over a cavity, and a deflecting structure, such as an electrodes, is provided for controllably exerting a force on the suspended portion of the waveguide. Exerting a deflecting force on the suspended portion of the waveguide induces controllable birefringence in the waveguide core and, thereby allows dynamic control over the polarization properties of light passing through the DPC. An array of DPC's of the present invention can be formed on a single substrate and used in an optical network, for example a WDM system whereby plural light signals traveling through a single optical fiber are demultiplexed for processing.

Abstract: A technique is provided for utilizing an optical fiber in a variety of sensing applications and environments by beneficially routing the optical fiber. A continuous optical fiber is created to provide optical continuity between two ends of the optical fiber. The optical continuity is created with the assistance of an optical turnaround constructed in a simple, dependable form able to control the bend of the optical fiber as it extends through the optical turnaround.

Abstract: An optical strain gage (1) for multi-axis strain measurement includes at least two linear light waveguide sections (2, 3, 4) with Bragg gratings (5). These are arranged next to one another in a prescribed angle (19) of 90° or 45° on a support layer (6) and are supplied with lightwaves by a common infeeding waveguide section (7). All of the light waveguide sections(2, 3, 4, 7) are provided preferably linearly on the support layer (6), and a beam dispersion element (8) is arranged between the infeeding waveguide section (7) and the measuring waveguide sections (2, 3, 4) containing the Bragg grating (5).

Abstract: In an optical circuit including multi-dimensional photonic crystals, in which the optical circuit has a structure (33), such as a light emitting member or a light receiving member, having a natural resonance frequency, another structure (34) having a natural resonance frequency slightly differing from the natural resonance frequency of the structure (33) is arranged in the vicinity of the structure (33) to control the directivity of localization and propagation of an electromagnetic field, light emission and light reception in a spatial region including the above structures in the multi-dimensional photonic crystals, in order to permit functional operations to be realized.

Abstract: Disclosed is a sensor capable of measuring motion in a harsh environment. The sensor uses a fiber optic sensor element formed within a core of an optical fiber that is disposed within an enclosure made of a high strength, corrosion-resistant material. The optical fiber is attached to a supporting fixture in a cantilever fashion so that the intrinsic internal mass of the optical fiber has the freedom to be affected by gravity so that an environmental disturbance acting on the sensor results in a bending strain being applied to the optical fiber. A Bragg grating is located at the bending portion of the optical fiber. The modulation of an optical signal promulgating through the optical fiber is sensed using conventional means and used to measure the magnitude of the environmental disturbance.

Abstract: An active sensor 10 is positioned on an outside of a pipe 60 so as to detect a thickness of the pipe. The active sensor comprises: an oscillator 15 capable of inputting oscillatory waves into the pipe and sweeping a frequency of the oscillatory waves within a desired range; and an optical fiber sensor mounted on the pipe, the optical fiber sensor detecting the oscillatory waves generated in the pipe.

Abstract: Disclosed is a method and apparatus which provides for alerting of potential fiber optic cable intrusion. A stress detector located at a fiber optic cable termination point detects stress on the fiber optic cable and generates an alarm signal in response to the stress detection. The alarm signal is transmitted to remote alarm units along the fiber optic right of way via a conductive metallic portion of the fiber optic cable (e.g., the fiber optic cable sheath). In response to receipt of an alarm signal, the alarm units initiate a perceptible (e.g., audible and/or visible) alarm. The stress detector may also determine a location of the stress, and generate an alarm signal addressed to a particular one or more alarm units in the vicinity of the stress location.

Abstract: A telecommunication fiber optic cable for gas pipeline application has a built-in leakage detecting device. The cable has an optical core including a number of telecommunication optical fibers, an outer jacket covering the optical core, and one or more gas leakage detector optical fibers. One or more gas leakage detector optical fibers are enclosed within the outer jacket. Preferably, the cable has a linearly extending rod reinforcing system having strength rods that force the cable to bend in a preferential bending place. Preferably, the leakage detector optical fibers are located at, or close to, a plane that is substantially orthogonal to the preferential bending plane and passing through the cable neutral axis.

Abstract: A method and device for moving optical beams including a conduit and an attached, independently movable structure that moves the conduit with up to 6 degrees of freedom both controlled and restricted as required. This structure may include a conductor positioned by an electromagnetic field generator. A cam or flexible capacitor plate or combination of such could also form the independently moveable structures. A control provides a current through the conductor, thereby providing a force on the conductor to move the conduit. A position sensor detects the position of the conduit and provides feedback to the control to aid in accurate and rapid movement.

Abstract: Some or all of the optical fibers of a single-mode or multi-mode cable are monitored for intrusion by transmitting through the fibers a signal which can be analyzed for changes in its characteristics which are indicative of movement as a prelude to an intrusion event. To avoid independent monitors of all of the fibers, in some cases the same light signal is looped through a plurality of the fibers in series by passive jumpers. Switches can be used to disconnect out those fibers which are compromised. As an alternative a plurality of separate monitoring signals can be provided each associated with its own sensor where unique combinations of the signals are transmitted through separate fibers allowing a higher number of fibers to be monitored than the number of signals.

Abstract: Optical systems for sensing chemicals. An example system includes a light source, a light sensor, a processing device in signal communication with the light source and the light sensor, and a fiber optic cable that receives light from the light source and delivers light to the light sensor. The fiber optic cable includes a cladding material that is permeable to a predefined substance and an optical fiber core surrounded by the cladding material. The optical fiber core is a single mode optical fiber having a diameter greater than 30 ?m. The optical fiber core includes a hollow center having a diameter between 1-50 ?m. The optical fiber core includes a plurality of lengthwise holes positioned to provide single mode light propagation properties. The plurality of lengthwise holes have a diameter between 0.2-4 ?m.

Abstract: An optical fiber strain sensor, a method of fabricating the same, and a method of sensing strain (1200). The method of strain sensing comprises providing an optical fiber having at least a first fiber Bragg grating (FBG) and a second FBG formed therein (1202); subjecting the optical fiber to a strain inducing force such that a grating period in the first FBG compresses and a grating period in the second FBG extends (1204); and optically interrogating the first and second FBG to determine peak reflection wavelengths of the first and second FBGs respectively (1206), whereby a separation between the peak reflection wavelengths of the first and second FBGs is representative of the strain induced.

Abstract: A catheter with many fiber optic pressure sensors. The sensor diaphragm is formed from a wafer with a thin silicon layer and a silicon substrate layer separated by a silicon dioxide layer. A method includes masking and etching channels through the silicon substrate layer in a pattern of concentric circles to form a concentric circular etched channels and cylindrical unetched portions of the silicon substrate layer between the channels, exposing the silicon dioxide in the etched regions, and dissolving the exposed silicon dioxide to expose the crystalline silicon layer in the etched regions. The unetched cylindrical portion of the silicon substrate forms the diaphragm support element and the thin silicon layer forms the diaphragm. After applying a reflective coating to the exposed thin silicon layer, the support element face is adhered to the end face of a tubular housing, and a fiber optic probe is inserted in the tubular housing.

Abstract: The present invention is a diaphragm-fiber optic sensor (DFOS), interferometric sensor. This DFOS is based on the principles of Fabry-Perot and Michelson/Mach-Zehnder. The sensor is low cost and is designed with high efficiency, reliability, and Q-point stability, fabricated using MEMS (micro mechanic-electrical system) technology, and has demonstrated excellent performance. A DFOS according to the invention includes a cavity between two surfaces: a diaphragm made of silicon or other material with a rigid body (or boss) at the center and clamped along its edge, and the endface of a single mode optic fiber. By utilizing MEMS technology, the gap width between the diaphragm and the fiber endface is made accurately, ranging from 1 micron to 10 microns.

Abstract: Disclosed is an impact detection system including: an optical fiber including a plurality of sensor sections to reflect light, a wavelength band of the reflected light vibrates depending on an elastic wave propagating through a subject to be inspected; a light source to input light into the optical fiber; optical filters each connected to an output terminal of the optical fiber; and an arithmetic processing unit to detect the impact from output values of sensor sections, wherein the wavelength bands of the sensor sections in the optical fiber are distributed such that the vibration bands caused by the impact to be detected do not overlap with each other, and a pass band of the optical filter corresponding to one of the sensor sections is distributed in the vibration band caused by the detection object, and is distributed in both sides of a center of the wavelength band of the one sensor section.

Abstract: An optical waveguide sensing method and device in which a waveguide layer receives an optical signal and propagates the optical signal in accordance with a predetermined optical waveguide propagation mode. A testing medium surface in communication with the waveguide layer is responsive to a testing medium for modifying at least one characteristic of the propagated optical signal in relation to a given parameter of the testing medium. In this manner, the modified characteristic of the propagated optical signal can be measured in view of determining the given parameter of the testing medium.

Abstract: A distributed fiber optic sensor device that employs a photonic band gap fiber as a sensing medium, in which: the photonic band gap fiber, which is the sensing medium, includes: a quartz section; and a plurality of high refractive index portions provided in the quartz section along the longitudinal direction of the fiber, the high refractive index portions being photonic band gaps periodically arranged to form a triangular-lattice pattern; the photonic band gap fiber has a bandwidth in which a wavelength band of a Stokes beam generated due to stimulated Raman scattering is included; and the photonic band gap fiber has a band gap width in which a wavelength band of an anti-Stokes beam generated due to the stimulated Raman scattering and a wavelength band of an optical signal incident into the photonic band gap fiber are included.

Abstract: A telecommunications optical fiber is secured against intrusion by detecting manipulation of the optical fiber prior to an intrusion event. This can be used in a non-locating system where the detection end is opposite the transmit end or in a locating system which uses Fresnel reflections and Rayleigh backscattering to the transmit end to detect and then locate the motion. The Rayleigh backscattering time sliced data can be stored in a register until an intrusion event is detected. The detection is carried out by a polarization detection system which includes an optical splitter which is manufactured in simplified form for economic construction. This uses a non-calibrated splitter and less than all four of the Stokes parameters. It can use a polarimeter type function limited to linear and circular polarization or two linear polarizers at 90 degrees.

Abstract: The invention provides a miniature robust fiber optic pressure sensor. The miniature fiber optic sensor comprises a Fabry-Perot chip bonded to an optical fiber. The invention provides a new sensor design that reduces the amount of adhesive required to bond the optical fiber to the Fabry-Perot sensor such that the sensor is less sensitive to moisture. The invention also provides manufacturing methods of the sensor comprising a method based on etching and a method based on using an excimer laser. The invention also provides a chip design that renders the chip less sensitive to thermal changes. The invention also provides a chip design in which a sensor diaphragm has a well-defined thickness. The invention also provides a chip design that protects the chip from etching.

Abstract: A device includes a stationary, rotary component, and a fiber optic sensing system. The fiber optic sensing system includes a cable having one or more fiber optic sensors disposed on the stationary component, the rotary component, or combinations thereof. The fiber optic sensing system is configured to detect one or more first parameters including temperature, strain, pressure, vibration, torque; or combinations thereof related to the stationary component, the rotary component, or combinations thereof. The one or more first parameters is used to determine one or more second parameters including thermal expansion, clearance, fluid flow rate variation, condensation, fluid leakage, thermal loss, life, thermal stress, or combinations thereof related to the stationary component, the rotary component, or combinations thereof.

Abstract: A system measures the strain of an object. The system includes a laser source for generating an output radiation, a strainable optical fiber having first and second facets, and means for calculating a measure of a strain of the optical fiber. The first facet is coupled to the laser source for receiving the output radiation and for transmitting therefrom a guided radiation over the optical fiber towards the second facet. The second facet is adapted to receive the guided radiation and to reflect a corresponding reflected radiation towards the first facet. The laser source is a self-mixing type adapted to receive at least part of the reflected radiation and to mix the output radiation with the received radiation. The calculating means calculate the measure of the strain of the optical fiber through the linear displacement of the second section measured by the self-mixing effect in the laser source.

Abstract: The present invention is a method and an apparatus for tuning an optical delay line. In one embodiment, an optical delay line includes at least one ring resonator in which light is guided or is confined and at least one heater positioned laterally from the ring resonator. The heater produces heat in a localized area, allowing for the tuning of individual delay elements with minimal crosstalk.

Abstract: The present invention provides an apparatus for pressure sensing. The apparatus comprises a series of Bragg gratings and a light guide incorporating the series of Bragg gratings. The apparatus also comprises a plurality of moveable wall portions having opposite first and second sides. Each moveable wall portion is positioned so that a change in pressure at one of the sides relative to a pressure at the other side will move the moveable wall portion that is coupled to respective Bragg gratings so that the movement of one of the moveable wall portion causes a force on the respective Bragg grating resulting in a change in strain of the respective Bragg grating. An internal space at each Bragg grating is in fluidal communication with an internal space at an adjacent Bragg grating whereby pressure differences between adjacent internal spaces are reduced.

Abstract: Disclosed is an inclinometer system capable of detecting the inclination of the ground using a fiber bragg grating sensor to precisely measure the deformation of the ground. The inclinometer system includes at least one measuring unit, and the measuring unit includes a body provided therein with a receiving part, a frame inserted into the body, a weight member inserted in to the frame and having one end hinged to the frame, the weight member rotating in cooperation to inclination of the body, an optical fiber 5 passing through both the body and the frame such that one end of the optical fiber is fixed to the weight member, a fixing member installed into the frame to fix an opposite end of the optical fiber, and a fiber bragg grating (FBG) sensor attached to the optical fiber.

Abstract: The present invention aims to provide an optical pressure sensor capable of detecting a more minute pressure change. A base film is formed with a through hole passing first and second surfaces, an optical fiber is fixed to the base film at a region other than the FBG portion such that the FBG portion is positioned on the through hole in plan view. The optical pressure sensor according to the present invention is attached to an object body such that the second surface of the base film is closely attached to a surface of the object body directly or indirectly.

Abstract: Methods and apparatuses for obtaining information, such as location and/or identification information, regarding sensors in optical paths such as optical fibers. One embodiment provides a method for identifying a location of a tag in an optical path. The tag is (1) adapted for producing a response to an optical signal propagating along the optical path; and (2) responsive to a variation of a physical parameter to vary the response to the optical signal. The method comprises causing a variation of the physical parameter and identifying the location of the tag at least in part by observing the response of the tag to the optical signal. The tag may be associated with a sensor such that a location of the sensor may be derived based on the location of the tag.

Abstract: Systems and methods for marine surveying of strata beneath a seafloor are disclosed, including, in certain aspects, systems employing one or more cables with a plurality of opto-electrical detector electrodes and an electrical wire with a fixed reference potential imposed thereon along the cable length. In a multi-cable system, the same fixed reference potential is applied to all wires in all cables. This abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, 37 C.F.R. 1.72(b).

Abstract: Disclosed is an apparatus for measuring convergence using a fiber Bragg grating sensor measuring slight deformation, capable of measuring the convergence such as the inclination or the gravitational acceleration of a measurement target including a bridge or a tunnel by measuring the deformation of the fiber Bragg grating sensor when the measurement target is inclined or vibrated, as well as a measurement method using the apparatus.

Abstract: A multi-core optical fiber sensor is described, which sensor includes an optical fiber having at least two cores, wherein the cores have collocated measurement portions, for example in-fiber interferometers or Bragg grating portions. In an exemplary embodiment, the fiber is provided with collocated measurement portions during fiberization to eliminate drift factors and to provide temperature corrected parameter measurement capabilities.

Abstract: Structural joint strain monitoring apparatus 92 comprises jacket means 52 in the form of first and second jacket elements 62, each having a primary jacket part 62a and substantially perpendicular secondary jacket part 62b which together define a compartment for receiving a joint, between two pipes 54, 56, to be monitored. The jacket means 52 additionally comprises two primary web elements 76, 78 provided between the primary and secondary jacket parts 62a, 62b. Three fiber Bragg grating (FBG) strain sensors 96, 98, 100 and an FBG temperature sensor 102 are provided within an optical fiber 104, bonded to the primary web elements 76, 78 and each end of the second jacket element 62 respectively, for measuring strain or temperature at their respective locations. The FBG sensors 96, 98, 100, 102 are optically coupled, via optical fiber 104, to optical fiber sensor interrogation apparatus 94, operable to interrogate each FBG sensor.

Abstract: A getter sheet is secured within a package element in a condition of elastic deformation by positioning the getter sheet between a base and a cap of a package with at least one portion of the getter sheet in contact with the package. When positioned within the package, the condition of elastic deformation may force the getter sheet into a vaulted form. Therefore, the getter sheet may be secured within the package without utilizing any additional parts or fasteners. The getter sheet comprises particulates of a getter applied to a sheet of material. The getter sheet may comprise a rectangular shape, an elliptical shape, or an octagonal shape. The getter sheet may be secured within the package when at least one portion of the getter sheet contacts one or more of a side surface of the cap, a bottom surface of the cap, and a top surface of the base.

Abstract: An optical motion sensing device included a sensor frame defining an opening, a sensor pad disposed in the opening, an optical sensing system adapted to detect an amount of movement of the sensor pad in the sensor frame, and an output unit. The optical sensing system includes an optical waveguide, an optical source device, and an optical detector. The optical waveguide is positioned within the sensor frame such that the movement of the sensor pad results in the flexing or compressing of the optical waveguide. The optical source device supplies optical energy to the optical waveguide. The optical detector detects an amount of optical energy exiting the optical waveguide. The output unit is configured to receive a signal indicative of the amount of optical energy exiting the optical waveguide and to generate a measure of the amount of movement of the sensor pad from the received signal.

Abstract: An impact-sensing, thermal insulation system includes a light source; an optical detector; and an optically-transmissive insulation optically coupled with the light source and the optical detector, the optically-transmissive insulation being operably associated with an outer surface of a pressure vessel. A missile includes a body; a propulsion system including a pressure vessel having an outer surface; and an impact-sensing, thermal insulation system operably associated with the outer surface of the pressure vessel. The impact-sensing, thermal insulation system includes a light source; an optical detector; and an optically-transmissive insulation optically coupled with the light source and the optical detector, the optically-transmissive insulation being operably associated with the outer surface of the pressure vessel.

Abstract: A temperature-compensated fibre optic strain gauge (10) for measuring strain of a host structure (5), the strain gauge (10) comprising: a mount (20) to be operatively attached to the host structure (5), the mount (20) having a void (19) separating a first section (17) of the mount (20) from a second section (18) of the mount (20); a first fiber Bragg grating (FBG) (30) recorded within a core of an optical fiber (11) to measure strain and temperature, the first FBG (30) being located transverse to the void (19) and a first end portion of the first FBG (30) is operatively attached to the first section (17) of the mount (20) and a second end portion of the first FBG (30) is operatively attached to the second section (18) of the mount (20), the end portions of the first FBG (30) being pre-strained by an amount larger than a predetermined operational range of the first FBG (30); a second fiber Bragg grating (FBG) (40) recorded within the core of the optical fiber (11) to measure temperature, the temperature measur

Abstract: Optical time domain reflectometry caused by absorption of a volatile or analyte into the fiber optic cladding is used an optical nose. The fiber optics (14) are covered with a gas permeable film (44) which is patterned to leave millimeter wide gas permeable notches (48a-48d). The notches contain a sensing polymer that responds to different gases by expanding or contracting.

Abstract: A waveguide sensor according to an embodiment of the present invention includes: a substrate; a first underclad arranged on one side of the substrate; a first sensing core arranged on outer side of the first underclad and having a stripe pattern which extends in one direction; a first overclad arranged on outer side of the first sensing core; a second underclad arranged on another side of the substrate; a second sensing core arranged on outer side of the second underclad and having a stripe pattern which extends in a direction not parallel to the direction in which the first sensing core extends; and a second overclad arranged on outer side of the second sensing core. A first grooved part which extends in a direction not parallel to the direction in which the first sensing core extends is formed on the first overclad, so that the first grooved part and the first sensing core together form a first grating in a plane view.

Abstract: A disturbance, such as vibration from human activity, is located along a fiberoptic waveguide configuration (301-304) with two interferometers (801, 802) of the same or different types, such as Mach-Zehnder, Sagnac, and Michelson interferometers. Carrier signals from a source (101) are split at the interferometer inputs (201, 202) and re-combined at the outputs (701, 702) after propagating through the detection zone (401), where phase variations are induced by the disturbance (501). Phase responsive receivers (901, 902) detect phase relationships (1001, 1002) between the carrier signals over time. A processor (1101) combines the phase relationships into composite signals according to equations that differ for different interferometer configurations, with a time lag between or a ratio of the composite signals representing the location of the disturbance.

Abstract: An apparatus and method for testing composite structures in which ultrasonic waves are used to detect disbonds in the structures are described. The apparatus comprises a flexible structure carrying acousto-optical transducers such as fiber Bragg gratings. During use, the apparatus is mechanically and conformally coupled to the structure under test.

Abstract: An embodiment of the invention is a remote sensor that has an optical fiber terminating in a tip. A thin film porous particle having a characteristic optical response that changes in the presence of an analyte is optically coupled and physically attached to the tip of the optical fiber. The optical response of the particle changes in the presence of analyte, and the particle also serves to concentrate analyte. The thin film porous particle can be functionalized toward sensitivity for a predetermined analyte or analytes. A method of remote sensing exposes the remote sensor to an environment to be monitored for analyte. The thin film porous particle is probed with a beam of light. Reflected light is monitored through the optical fiber for a shift in frequency or intensity.

Abstract: Structural member bend radius sensor apparatus 90 comprises three fibre Bragg grating (FBG) strain sensors 102 provided within three optical fibres 14, 16, 18. The optical fibres 14, 16, 18 and the FBGs 102 are embedded within a part-cylindrical shaped carrier member 92. The fibres 14, 16, 18 are provided at three spaced locations across the shaped carrier member 92 so that, in use, the three respective FBG strain sensors will be located at three different angular positions around the circumference of the structural member (pipe) 68. Structural member shape measurement apparatus 100 comprises four bend radius sensor apparatus 90 provided at four bend radius measurement positions along the pipe 68. The four bend radius sensor apparatus 90 shown share their optical fibres 14, 16, 18, and a single shaped carrier member 92. The shape measurement apparatus 100 further comprises FBG interrogation apparatus 104.

Abstract: A system and method for a structure monitoring and locating a disturbance event is disclosed. The system includes a compact transceiver chip sending optical signals in three optical fibers that encompass the monitored structure appropriately. The fiber arrangement has different density in different parts of the monitored structure, such as, for example, critical places in the structure may have larger number of fiber loops surrounding them. All fibers transmit signals in both directions: from the transceiver to a returning point and back. A set of two detectors registers the returning signals, and a time delay between those signals is calculated, which is indicative of the disturbance event location. Polarization states of the returning signals are controlled by transceiver built-in controllers. The event location is determined with different sensitivity in different parts of the monitored structure depending on the density of fibers in these parts.

Abstract: A strain sensor includes an optical fiber with at least one optical fiber, a reflector body with a reflective surface, a housing affixed to the optical fiber probe and to the reflector body. The reflective surface is spaced apart at a distance d from the ends of the probe's fibers and receives light from the end of the fiber and to reflect at least a portion of the light into the end of the fiber. The housing is attached to the fiber probe at a first end of the housing and attached to the reflector body at a second end of the housing. The housing is affixed to the material to be measured, and in the material causes a change in gap between the fiber end and the reflective surface, modulating the amount of light received in the receiving fiber, detectable by a photodetector connected to the receiving fiber.

Abstract: A distributed elongated optical fiber detection system is provided, having at least one sensitive region, and being capable of detecting the occurrence and location(s) of one or more events along its length that cause one or more perturbations in the at least one sensitive region. In one embodiment of the invention, the novel detection system includes, at its first end, an optical signal source capable of launching a signal in a first signal mode through an optical fiber waveguide comprising at least one sensitive region along its length, and configured for transmitting at least two signal modes therethrough, toward its second end. A reflecting device, capable of reflecting only signals in a second signal mode, is positioned at the second end of the waveguide.

Abstract: A system serves to monitor a body exposed to high mechanical or thermal stress. The body has a surface that has at least one groove with two groove lateral walls which are oppositely disposed and adjacent to the surface. An optical waveguide devoid of protective coating, which has a light-guiding core and a casing surrounding it and in which at least one sensor is provided for the optical detection of a measurement variable, is embedded in the groove. The optical waveguide is fixed in place in an area of one of the groove lateral walls, which is adjacent to the surface, by means of at least one caulking.

Abstract: A shape sensing system to determine the position and orientation of one link with respect to another link in a kinematic chain. An optical fiber is coupled to two or more links in a kinematic chain. A shape sensing segment is defined to start at a proximal link and to end at a distal link, crossing one or more joints. A reference frame is defined at the start of the shape sensing segment. As the joints move, an interrogator senses strain in the shape sensing segment. The sensed strain is used to output a Cartesian position and orientation of the end of the shape sensing segment with respect to the reference frame defined at the start of the shape sensing segment. The pose of the kinematic chain is determined from the Cartesian positions and orientations of one or more shape sensing segments defined for the kinematic chain and from an a priori model and constraints of the kinematic chain.

Abstract: Localized strain is effectively eliminated in a shape sensing optical fiber where the fiber exits a link in a kinematic chain. In one aspect, the fiber is positioned in a channel within a fiber fixture portion of the link, and a surface of a lip of the channel is curved. The curved surface of the lip begins tangent to a wall of the channel and has a maximum radius of curvature that is less than the minimum bend radius that the fiber will experience during shape sensing. In another aspect the fiber is positioned within a shape memory alloy tube that extends from the link.

Abstract: An optical module is configured with a combination of a single-mode oscillating light source and an optical filter. In this optical module, the single-mode oscillating light source outputs a single-mode, frequency-modulated signal. Further, the optical filter converts the frequency modulation to an amplitude modulation. And, the single-mode oscillating light source and the optical filter are packaged without active alignment on the same substrate. Accordingly, it is possible to realize an optical module in a simple and low-cost configuration by packaging the single-mode oscillating light source and the optical filter by passive alignment, without active alignment, on the same substrate, and by using a simple optical filter such as a waveguide ring resonator, which converts a frequency modulation to an amplitude modulation.

Abstract: A plurality of microwave signals are converted into optical signals which are directed against an optically reflective surface, whereby the optical signals reflected off of the optically reflective surface are received and converted into microwave signals, which are passed through a Fourier Transformer for extracting information of interest.

Abstract: Disclosed an impact detection system including: three or more optical fiber sensors disposed respectively in different positions, the sensors not being in alignment with one another, in which the sensors each includes a core portion to have a grating portion formed therein, the grating portion has a plurality of gratings; light source; two or more optical filters having different pass bands to one another to an output light of one of the optical fiber sensors; and an arithmetic processing apparatus to perform arithmetic processing of output values of the three or more optical fiber sensors through the optical filters so as to specify a position on the subject where an impact is loaded, the output values being obtained when the impact is loaded on the subject.

Abstract: This disclosure generally pertains to a method for manufacturing a distributed optical fiber scrim comprising a functional optical fiber, the functional optical fiber scrim thus manufactured, and composites in which an optical fiber scrim is incorporated. The present disclosure describes a variety of textile scrims, particularly adhesively bonded nonwoven scrim materials, each comprising at least one optical fiber with a continuous path across at least the length or width of the fabric. Such optical fiber scrims may be useful as sensor components (for example, as a detector of breakage, strain, pressure, or torque), as illumination components (for example, in a variety of light-providing applications), or as data-distribution components, either alone or in combination with other materials, such as fabrics, films, foams, and the like.