Abstract: A panel having a central panel element formed of a composite material, having peripheral edges formed of a weldable material, such as steel. In one form, the panel element is rectangular, and the panel element on two of its opposite edges have a corrugated profile, while the other two of its opposite edges have a linear profile. Multiple panels may be joined together by welding at the peripheral edges, to form a secure container. The composite material of the panel element in some forms, includes intrusion sensors, for example including optical fiber pathways at electrically conductive pathways, as well as processors for effecting data transfer and analyses and secure communications. In some embodiments, the electrically conductive pathways include one or more bypass resistors to produce a different circuit resistance upon interruption of one or more of the pathways.

Abstract: In accordance with one exemplary embodiment the invention provides a multi-parameter fiber optic sensing system with an aperiodic sapphire fiber grating as sensing element for simultaneous temperature, strain, NOx, CO, O2 and H2 gas detection. The exemplary sensing system includes an aperiodic fiber grating with an alternative refractive index modulation for such multi-function sensing and determination. Fabrication of such quasiperiodic grating structures can be made with point-by-point UV laser inscribing, diamond saw micromachining, and phase mask-based coating and chemical etching methods. In the exemplary embodiment, simultaneous detections on multi-parameter can be distributed, but not limited, in gas/steam turbine exhaust, in combustion and compressor, and in coal fired boilers etc.

Abstract: A hinge position sensor comprises first and second members connected together to provide a hinge, and an optical fiber or wave-guide connected between the first and second members to provide a communication link between the first and second members. A laser or LED is coupled to the optical fiber or wave-guide to transmit optical signals between the first and second members and the optical signal is received by a photo-detector. The optical fiber or wave-guide is physically distorted by actuation of the hinge such that light escapes from the optical fiber or wave-guide. The optical power level received by the photo-detector is used to determine the position of the hinge.

Abstract: An optical fiber sensor can be interposed between a bumper reinforcement and a load transmitting plate to extend in the direction of width of a vehicle along with the bumper reinforcement. In this case, when a change does not occur substantially in an immediately previous predetermined period in an output voltage of a light emission amount of the optical fiber sensor, a feedback control is performed in such a way that the change becomes a level of zero of the output voltage of the optical fiber sensor. In contrast, when a change in the output voltage is not substantially zero, the immediately previous state of emission of light is maintained. Accordingly, it is possible to effectively compensate a zero point shift caused by a temperature change or/and an aging degradation of the optical fiber sensor.

Abstract: A method is provided for producing an optical acoustic sensor. In one embodiment, a method comprises winding a single-mode optical sensor fiber around at least one mandrel. The optical acoustic sensor fiber can comprise a core region having a diameter of about 2 ?m to about 8 ?m and a cladding region having an outer diameter of about 8 ?m to about 20 ?m. The method can also comprise interconnecting the at least one mandrel into an optical acoustic sensor.

Abstract: The present invention provides an apparatus for distributed pressure sensing. The apparatus comprises a series of Bragg gratings, a light guide incorporating the series of Bragg gratings and a plurality of a moveable wall portion. The moveable wall portions have opposite first and second sides and 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. The moveable wall portions are 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. The apparatus also comprises at least one rigid member that is attached at attachment regions between which a sensing region of at least one Bragg grating is defined.

Abstract: A monolithic device for determining a translation, the monolithic device being fabricated from a single continuous piece of a glass substrate. The monolithic device comprises at least one frame, a moving platform linked to the at least one frame and an optical transducer. The at least one frame is fabricated from the glass substrate. The moving platform is fabricated from the glass substrate, wherein the moving platform is linked to the at least one frame via at least one elastic hinge. The at least one elastic hinge is also fabricated from the glass substrate. The optical transducer is imbedded into the moving platform and the at least one frame.

Abstract: A sensor system for use in a well bore includes a metal-clad fibre-optic cable, the fibre optic cable include one or more Bragg gratings, and each Bragg grating is configured such that a value or change in a physical parameter to be measured results in a measurable value or change in the Bragg grating. The sensor system is included in a tool moveable through a drill string. The Bragg gratings are subjected to a strain related to the well bore's pressure, such that the pressure can be determined from the characteristics of the Bragg grating.

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: The present invention is directed to a hitpoint sensor for a surface of interest, the hitpoint sensor having an optical fiber which is wound around or otherwise covering the surface, and a data processor connected to the ends of the optical fiber. When a collision with the surface occurs, light is generated which passes through the optical fiber. The ends of the fiber are connected to the data processor which uses arrival time information of the light signals arriving at the processor to determine the impact location on the surface. There are several modes in which the processor can operate to make this calculation.

Abstract: A pressure sensor including: a deflectable diaphragm including a substantially central boss and channel; and, an optical waveguide having first and second arms, wherein the first arm is substantially aligned with an edge of the boss and the second arm is substantially aligned with an edge of the channel.

Abstract: Intrusion detection for a multimode fiber optic cable uses a light signal launched into the fiber through the low ratio leg of a tap coupler to establish a narrow spectral width, under-filled non-uniform mode field power distribution in the cable. A small portion of the higher order signal modes at the remote end is monitored for transient changes in the mode field power distribution which are characteristic of fiber intrusion to activate an alarm. The active signal of a multimode optical fiber is monitored for both signal degradation and transient power disturbance patterns that could indicate fiber damage or physical intrusion. A translator can be provided in an existing optical fiber system in which the data signals are translated in wavelength and/or launch conditions to optimize the monitoring signals in an otherwise non-optimized system.

Abstract: Intrusion detection of one section only of a multimode fiber uses a light signal launched into the fiber at a location spaced from the source through a single mode fiber to establish a narrow spectral width, under-filled non-uniform mode field power distribution in the fiber. A small portion of the higher order signal modes at the a second location also spaced from the destination is sampled by a tap coupler and monitored for transient changes in the mode field power distribution which are characteristic of intrusion to activate an alarm. A fiber being used for data transmission can be monitored for intrusion by introducing a monitor wavelength different from that of the data signal. Central to this invention is the use of a bulk optic (commonly referred to as a pass/reflect) wavelength division multiplexer, one which maintains the modal distribution within the fiber.

Abstract: A sensor for a security system is disclosed to detect intrusions at one or more predetermined locations wherein each location includes a moveable member which must be moved in order to intrude the location. The system includes a fiber network routed in close proximity to one or more locations. The sensor comprises a sensor housing for being disposed at a location to detect a predetermined movement of the moveable member from a secure position to an unsecured position, and means for mounting the sensor housing in a stationary position at the location without a physical connection to the moveable member. The sensor housing includes a fiber inlet and a fiber outlet, and a fiber chamber for receiving a predetermined sensor fiber of the fiber network being routed through the sensor housing.

Abstract: An assembly senses fluid pressure variations within a passageway along a length of a flowline. A fiber optic cable is disposed axially within the passageway of the flowline. The fiber optic cable experiences a mechanical strain responsive to variations in the fluid pressure of the fluid communicating through the passageway of the flowline along the length of the flowline. The assembly also includes an enhancing layer surrounding the fiber optic cable. The enhancing layer is more responsive to the fluid pressure of the fluid communicating through the passageway of the cable than the fiber optic cable, which enhances the responsiveness of the fiber optic cable to the pressure by magnifying the mechanical strain associated with the fiber optic cable within a particular region of varying fluid pressure. Strain associated with the cable is communicated through back-reflected light.

Abstract: A Fabry-Perot optical sensor for sensing a parameter such as pressure or the like is provided. The sensor includes a lead optical fiber from the end of which projects a spacer having an end surface curving inwardly. A diaphragm extends across the forward end of the spacer. The diaphragm is flexible in response to the parameter to be measured and defines a forward reflector of the Fabry-Perot cavity within the optical sensor. A method for manufacturing such a sensor is also provided.

Abstract: A touch indication device comprises a light guide structure for passing light of a light source via total internal reflection. A touch surface disturbs the total internal reflection when touched, causing light to leave the light guide structure. A light enhancement layer converts the light leaving the light guide and sends the converted light to a light detector. The light enhancement layer amplifies the intensity and/or changes the color of the light leaving the light guide. The detector determines the position of the touch on the touch surface based on the light from the light enhancement layer.

Abstract: An optical sensor includes a support structure. An optical fiber has a plurality of bends arranged proximate the support structure. The optical fiber follows a circuitous path and is adapted to establish a detection zone.

Abstract: A method and device are presented for use in determining a rate of rotation of an object. The device comprises a light guide comprising an arrangement of a plurality of coupled optical resonators arranged along a curvilinear optical path. This allows for determining a change in at least one of the light phase and frequency affected by the light propagation through the curvilinear path during the device rotation, said change being indicative of the rotation rate of the light guide.

Abstract: Designs of fiber stretcher apparatus using one or more linear actuators to stretch fiber loops for various applications including variable optical delay lines and devices using such delay lines.

Abstract: A system for measuring simultaneously both temperature and ac voltage and/or ac current, the system comprising: a piezo-electric sensor; and optical fiber that includes an optical strain sensor being in contact with the piezo-electric sensor and able to expand or contract therewith and an analyzer for analyzing an optical output of the fiber and strain sensor in response to an optical input, the analyzer being operable to use the optical output to determine the temperature and the ac voltage and/or ac current.

Abstract: A multiplexed fiber optic sensor system including a first optical fiber having a first end arranged to receive light from a light souce, at least two optical fibers having diameters smaller than the first optical fiber, and at least two fiber optic sensors, each of the at least two smaller diameter optical fibers arranged between the first optical fiber and one of the sensors for transmitting light from the first optical fiber to that sensor. The sensors can be static or dynamic pressure sensors, strain sensors, temperature sensors or other environmental sensors.

Abstract: An optical measurement device for measuring strain related to deformation of a deformable surface of a component. The optical measurement device includes a fiber tension structure including opposing longitudinal end sections attached to the deformable surface. An optical fiber is tensioned by the fiber tension structure and includes a section defining a Bragg grating. The fiber tension structure includes a displaceable portion for forming a structural break between the longitudinal end sections where the fiber tension structure separates to form a gap between the first and second longitudinal end sections. The longitudinal end sections are movable independently of each other after formation of the structural break in the fiber tensioning structure.

Abstract: Intrusion detection of one section only of a multimode fiber uses a light signal launched into the fiber at a location spaced from the source through a single mode fiber to establish a narrow spectral width, under-filled non-uniform mode field power distribution in the fiber. A small portion of the higher order signal modes at the a second location also spaced from the destination is sampled by a tap coupler and monitored for transient changes in the mode field power distribution which are characteristic of intrusion to activate an alarm. The active signal of a multimode optical fiber is monitored for both signal degradation and transient power disturbance patterns that could indicate fiber damage or physical intrusion. A translator can be provided in an existing optical fiber system in which the data signals are translated in wavelength and/or launch conditions to optimize the monitoring signals in an otherwise non-optimized system.

Abstract: An acoustic sensor, such as a hydrophone, is deployable in a fluidic media having high temperature, high pressure, and/or potentially caustic chemicals. The hydrophone includes a housing filled with an internal fluid and containing a sensing mandrel. The sensing mandrel senses the acoustic pressure transmitted to the internal fluid through a diaphragm. The sensing mandrel preferably includes a polymer tubular mandrel having a coil of optical fiber wound and bonded to its outer surface. The sensing mandrel can be suspended within the housing instead of being rigidly attached thereto. To relieve pressure created by thermal expansion of the internal fluid, the flexible diaphragm, a filler member, a pressure compensator, or combinations thereof can be used. The filler member is mounted in the hydrophone and reduces the amount of internal fluid required in the housing. The compensator may be a bellows or a buffer tube.

Abstract: To provide a low-cost FBG sensing device having a high reliability, suitable for high-speed measurement such as vibration measurement, able to perform a remote measurement, and simple data processing, the FBG sensing device comprising one or more light sources each outputting a light having fixed output wavelength, one or more fiber-Bragg gratings each having a reflection wavelength band having an attenuation band where the magnitude of reflection attenuates with distance from the center wavelength, the fiber-Bragg gratings reflecting the lights output from said light sources, light receiving units corresponding said fiber-Bragg gratings respectively and receiving the light reflected by the corresponding fiber-Bragg grating, wherein intensities of reflected lights each of which changes corresponding to the attenuation band that changes due to a distortion produced at each of the fiber-Bragg gratings are detected to detect the distortions.

Abstract: A polymer waveguide resonator device for high-frequency ultrasound detection having a optical resonator coupled to a straight optical waveguide which serves as input and output ports. Acoustic waves irradiating the waveguide induce strain modifying the waveguide cross-section or other design property. As a consequence, the effective refractive index of optical waves propagating along the ring is modified. The sharp wavelength dependence of the high Q-factor resonator enhances the optical response to acoustic strain. High sensitivity is demonstrated experimentally in detecting broadband ultrasound pulses from a 10 MHz transducer.

Abstract: A fiber optic polarimetric strain sensor and associated data acquisition system capable of all-optical measurements of physical parameters, such as structural strain, gas and liquid pressure, acceleration and vibration, gas and liquid flow rate, and force without fire and explosion hazards associated with conventional strain gage technologies, such as resistance foil strain gages. The polarimetric strain sensor houses a sensitive element—a length of single-mode optic fiber—changing polarization of a single-mode optical signal running in the fiber under some mechanical effects, specifically twisting and radial compressing. A multi-channel time division multiplexing data acquisition system indicates the polarization state deviation caused by the strain, so allow measuring the parameters. The invention may be embodied for measurements of any phenomenon that can be transformed in stress on an optical fiber.

Abstract: Optical coupling device operates over a bidirectional data link between at least first and second communicators, each communicating data along a common wire of the data link. The device includes at least first and second optical couplers, each including a photon flux source and a photon flux detector. The photon flux source of the first and second optical couplers, respectively, is commanded by the first and second communicator, respectively. The photon flux detector of the first and second optical coupler, respectively, produces a signal on the data link at the first and second communicator, respectively, in response to the photon flux source of the second and first optical coupler, respectively, from the second and first communicator, respectively. An inhibitor inhibits the photon flux source of the second and first optical coupler, respectively, in response to an activation of the photon flux source of the first and second optical coupler, respectively.

Abstract: An optical accelerometer includes means for changing the length of at least one optical fiber in response to acceleration functionally coupled to the at least one optical fiber. The fiber and the means for changing length are enclosed in a pressure compensated housing. The housing is filled with a substantially incompressible fluid or gel.

Abstract: A cabinet tamper detection device is disclosed. The tamper detection device includes a first portion and a second portion. The first portion includes a housing and a first magnet movable relative to the housing between a first position and a second position. The second portion includes a second magnet. The first and the second magnets are configured such that the second magnet applies a magnetic force on the first magnet to keep the first magnet at the first position when the first and the second magnets are at a predetermined relative position. When at least one of the first and the second magnets is moved from the predetermined relative position, the first magnet moves from the first position to the second position to trigger a tamper warning.

Abstract: Fuel injectors (10) for internal combustion engines are modified and equipped with fiber optic fuel pressure sensors (12) and fiber optic combustion pressure sensors (14). The combustion pressure sensors (14) are located in separate channels (26) formed in the fuel injectors with the lower portion (22) of the channels leading to the combustion chambers. Above the combustion pressure sensors (14) are fiber optic leads (24). In the preferred embodiments the sensors (46) are equipped with diaphragms (40) of novel shape (48) and employ multiple pairs of fibers (86, 88), temperature sensitive components (72, 74, 126) and novel compensation and status monitoring circuits (FIGS. 6, 9, 10, 14, 15, 18).

Abstract: An optical sensor has a core, a cladding, and an over-layer. In some embodiments the optical sensor also has a sensing layer. The over-layer acts as a sensitivity enhancement layer, with a refractive index larger than that of the cladding layers. A periodic structure, such as a long-period grating (LPG), is formed in the core. A transmission spectrum of the device shows several notches due to the existence of the LPG. A change in the sensing layer's refractive index and/or thickness results in a shift in the notch wavelengths of the LPG. By choosing proper refractive indices and thicknesses of the core, the cladding and the over-layer, the shift in the notch wavelengths can be significantly enhanced.

Abstract: The present invention discloses a fiber Bragg grating sensor system.

Abstract: An optical resonator includes a reflective element and an optical fiber. The optical fiber is positioned relative to the reflective element such that light emitted from the optical fiber is reflected by the reflective element. The optical resonator has an optical resonance with a resonance lineshape that is asymmetric as a function of wavelength.

Abstract: Optical fibers, especially those having a core layer, a cladding layer over the core layer, FBG's formed in the core layer, the cladding layer, or both, a buffer layer over the cladding layer, and an outer jacketing layer.

Abstract: A wear determination device for determining vibration in a turbine engine component to reduce wear in a turbine engine. The wear determination device may be capable of measuring vibrations in a turbine engine component. The vibration measurement may be used to determine vibrations in a turbine engine to identify wear locations and sources of wear. The wear determination device may be configured such that multiple locations in a turbine engine may be monitored on a single turbine engine by moving the wear determination device from location to location.

Abstract: An optical sensor comprises an optical element having diffractive elements and a sensing region. The diffractive elements are collectively arranged to comprise spectral and spatial transformation information and to transform an input optical signal into an output optical signal according to the transformation information. The sensing region is arranged for receiving sample material so that the optical signals spatially overlap the sample material in the sensing region. The diffractive element set and the sensing region are arranged so that the spectral or spatial transformation information varies according to an optical property of the sample material. A sensing method comprises: receiving into the sensing region the sample material; receiving into the optical element the input optical signal; and receiving from the optical element the output optical signal. The method may further comprise measuring the variation of the spectral transformation information resulting from the sample substance.

Abstract: An apparatus includes a multicore fiber including three cores. The three cores include two pairs of cores, each pair of cores lying in a plane. The planes of the two pairs of cores are non-coplanar. The multicore fiber includes a rosette, the rosette including three coplanar interferometers. Each interferometer of the three interferometers are located in a respective core of the three cores. Each interferometer includes a first reflector and a second reflector. The first reflectors of the rosette are coplanar. The second reflectors of the rosette are coplanar.

Abstract: A device comprising a fiber grating loop ringdown (FGLRD) system of analysis is disclosed. A fiber Bragg grating (FBG) or Long-Period grating (LPG) written in a section of single mode fused silica fiber is incorporated into a fiber loop. By utilizing the wing areas of the gratings' bandwidth as a wavelength dependent attenuator of the light transmission, a fiber grating loop ringdown concept is formed. One aspect of the present invention is temperature sensing, which has been demonstrated using the disclosed device. Temperature measurements in the areas of accuracy, stability, high temperature, and dynamic range are also described.

Abstract: An optical fiber sensor for detecting curvature of a body/structure comprises a cladding having an outer periphery. A central core receives and transmits light. The central core has Bragg gratings and is positioned in neutral planes of the cladding. Peripheral cores receive and transmit light. The peripheral cores have Bragg gratings and are peripherally positioned in the cladding with respect to the neutral planes. A connection configuration is provided in the outer periphery of the cladding to attach the optical fiber sensor to a body/structure such that the central core and the peripheral cores are in a predetermined orientation with respect to the body/structure to measure curvature of the body/structure.

Abstract: A method and system are disclosed for measuring pressure and other physical data, such as the temperature, elongation, torsion and bending at any point along the length of an elongate carrier tube by means of one or more coiled optical fibers that are embedded in the wall the tube such that deformation of the carrier tube induces strain in each optical fiber. In use a pulsed laser light source transmits a sequence of light pulses of a selected wavelength from an upstream end of each fiber into a coiled substantially uniform light guide channel provided by the optical fiber and a light sensor assembly detects any shift in wavelength of the light pulses backscattered from various locations along the length of the light guide channel. A signal processing assembly then calculates a strain pattern along the length of the fiber, and a pressure difference between the interior and exterior of the tube, at various locations along the length of the carrier tube.

Abstract: An optical fiber sensor for detecting curvature of a body/structure comprises a cladding having an outer periphery. A central core receives and transmits light. The central core has Bragg gratings and is positioned in neutral planes of the cladding. Peripheral cores receive and transmit light. The peripheral cores have Bragg gratings and are peripherally positioned in the cladding with respect to the neutral planes. A connection configuration is provided in the outer periphery of the cladding to attach the optical fiber sensor to a body/structure such that the central core and the peripheral cores are in a predetermined orientation with respect to the body/structure to measure curvature of the body/structure.

Abstract: The present invention relates to a determination of a physical state of an optical device by measuring a response signal. At least two subsequent measurements are executed. Therefore, a first optical signal is transmitted to the optical device, wherein a first optical property of said first signal is varied according to a first function of the time. A second optical property of a first response signal returning from the optical device is measured over the time and a first result function of the second optical property of the first response signal over the first optical property of first optical signal is established. Further, a second optical signal is transmitted to the optical device, wherein the first optical property of said signal is varied according to a second function of the time that is different from the first function of time.

Abstract: A multi-core optical fiber pressure 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 arranged such that a pressure induced force will act on the multi-core fiber at said collocated position, affecting the light guiding cores in a different manner. In another exemplary embodiment, the optical fiber is configured to bend in response to pressure changes.

Abstract: A photonic crystal system and a method for controlling the direction of radiation propagation are disclosed. The photonic crystal system includes a photonic crystal and a deformation source positioned to deform the photonic crystal. The photonic crystal system optionally includes a radiation source that emits radiation at a frequency within a frequency range over which the photonic crystal exhibits a negative index of refraction.

Abstract: An optical transducer 100, 200 and method for the simultaneous measurement of downhole pressure and temperature in a single- or multi-point configuration including a body 10a/10b with an elastic membrane 50 onto which at least one Bragg grating 60a/60b is attached, and at least an additional Bragg grating 60b/60a contained on the same optical fiber 30. The elastic membrane 50 conveys strain proportional to the pressure and temperature conditions to which is submitted said transducer to at least one Bragg grating 60a/60b, the portion of light not reflected by the Bragg gratings 60a, 60b continues along the remaining of the optical fiber 30.

Abstract: A multi-core optical fiber pressure 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 arranged such that a pressure induced force will act on the multi-core fiber at said collocated position, affecting the light guiding cores in a different manner. In another exemplary embodiment, the optical fiber is configured to bend in response to pressure changes.

Abstract: According to embodiments of the present invention, a distributed pressure and shear stress sensor includes a flexible substrate, such as PDMS, with a waveguide formed thereon. Along the waveguide path are several Bragg gratings. Each Bragg grating has a characteristic Bragg wavelength that shifts in response to an applied load due to elongation/compression of the grating. The wavelength shifts are monitored using a single input and a single output for the waveguide to determine the amount of applied pressure on the gratings. To measure shear stress, two flexible substrates with the waveguide and Bragg gratings are placed on top of each other such that the waveguides and gratings are perpendicular to each other. To fabricate the distributive pressure and shear sensor, a unique micro-molding technique is used wherein gratings are stamped into PDMS, for example.

Abstract: There is provided a portable fiber optic cable based intrusion detection system in which support posts are driven into the earth to define a perimeter. A portably mountable fiber optic cable attenuator is installed to each support post. The fiber optic cable is wrapped around a first compressible member of the attenuator and then looped through a second compressible member. A retractable rod having a cross arm there through is elevated through the second compressible member to form an upper loop in fiber optic cable. The retractable rod is then retracted leaving the remaining upper loop. An external force on the fiber optic cable diminishes the upper loop about the cross arm thereby creating a microbend in the fiber optic cable. A light detector senses a reduced light intensity, caused by the microbend, at the end of the fiber optic cable which triggers an alarm.