CA2386348A1 - Flexible fiber optic microbend device, sensors, and method of use - Google Patents
Flexible fiber optic microbend device, sensors, and method of use Download PDFInfo
- Publication number
- CA2386348A1 CA2386348A1 CA002386348A CA2386348A CA2386348A1 CA 2386348 A1 CA2386348 A1 CA 2386348A1 CA 002386348 A CA002386348 A CA 002386348A CA 2386348 A CA2386348 A CA 2386348A CA 2386348 A1 CA2386348 A1 CA 2386348A1
- Authority
- CA
- Canada
- Prior art keywords
- flexible
- bending element
- microbend
- element grid
- fiber optic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims description 9
- 239000013305 flexible fiber Substances 0.000 title description 2
- 238000005452 bending Methods 0.000 claims abstract description 66
- 239000013307 optical fiber Substances 0.000 claims abstract description 43
- 239000000463 material Substances 0.000 claims abstract description 26
- 239000000835 fiber Substances 0.000 claims description 44
- 230000003287 optical effect Effects 0.000 claims description 19
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 10
- 229920001971 elastomer Polymers 0.000 claims description 10
- 239000000806 elastomer Substances 0.000 claims description 8
- 229910052710 silicon Inorganic materials 0.000 claims description 7
- 239000010703 silicon Substances 0.000 claims description 7
- 230000000737 periodic effect Effects 0.000 claims description 6
- 239000004033 plastic Substances 0.000 claims description 5
- 229920003023 plastic Polymers 0.000 claims description 5
- 239000000377 silicon dioxide Substances 0.000 claims description 5
- 229920002635 polyurethane Polymers 0.000 claims description 4
- 239000004814 polyurethane Substances 0.000 claims description 4
- 230000001681 protective effect Effects 0.000 claims description 3
- 239000004593 Epoxy Substances 0.000 claims description 2
- 238000005253 cladding Methods 0.000 claims description 2
- 229920001296 polysiloxane Polymers 0.000 claims description 2
- 238000012544 monitoring process Methods 0.000 claims 2
- 230000035945 sensitivity Effects 0.000 description 5
- 230000007812 deficiency Effects 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000003292 diminished effect Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000009941 weaving Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/36—Mechanical coupling means
- G02B6/3628—Mechanical coupling means for mounting fibres to supporting carriers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/24—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet
- G01L1/242—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre
- G01L1/243—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre using means for applying force perpendicular to the fibre axis
- G01L1/245—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre using means for applying force perpendicular to the fibre axis using microbending
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/14—Mode converters
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/264—Optical coupling means with optical elements between opposed fibre ends which perform a function other than beam splitting
- G02B6/266—Optical coupling means with optical elements between opposed fibre ends which perform a function other than beam splitting the optical element being an attenuator
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Transform (AREA)
- Force Measurement Appropriate To Specific Purposes (AREA)
- Light Guides In General And Applications Therefor (AREA)
- Biological Treatment Of Waste Water (AREA)
- Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
- Golf Clubs (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
A flexible microbend device for attachment to an optical fiber is provided.
The device comprises an upper bending element grid having at least one flexible element and a lower bending element grid having at least one flexible element. The upper bending element grid alternately engages the lower bending element grid. The flexible microbend device is attached to an optical fiber to form a sensor. The sensor may be either embedded in a host material or attached to a structure to detect various stresses or strains.
The device comprises an upper bending element grid having at least one flexible element and a lower bending element grid having at least one flexible element. The upper bending element grid alternately engages the lower bending element grid. The flexible microbend device is attached to an optical fiber to form a sensor. The sensor may be either embedded in a host material or attached to a structure to detect various stresses or strains.
Description
FLEXIBLE FIBER OPTIC MICROBEND DEVICE, SENSORS, AND METHOD OF USE
FIELD OF THE INVENTION
The present invention relates to fiber optic devices. In particular, it relates to a flexible microbend device that may be attached to an optical fiber and used in a sensor arrangement for measuring internal strain in a structure.
BACKGROUND OF THE INVENTION
Optical fibers are used to convey light between a light source and a light detector. Light in the fiber can be modulated by bending or otherwise distorting the fiber. This produces a modulated signal which can be picked up and processed by the light detector.
Microbend devices may be used to induce distortions in a fiber causing the light passing through the fiber to be modulated at a frequency corresponding to the force applied to the device. Typically, the device is applied to the fiber such that it surrounds the fiber.
One known device is a two jaw corrugated arrangement which squeezes an optical fiber to modulate the light signal passing therethrough. Macedo et al.
(U.S.
4,342,907) describes such a device where an upper piece is firmly connected to an enclosure by a support. A lower piece was attached to an elastic membrane.
When either a static pressure or dynamic time varying pressure reaches the membrane, it deflects pushing the lower piece, toward the upper piece, thus deforming the optical fiber which is held against the ridges of the device. They also describe another approach in U.S. 4,443,700 where two steel pieces having corrugated like surfaces with interleaving ridges form a vise which would be used to squeeze and thus deform the fiber. Such devices fail to have the compae;tness and flexibility desired for measuring forces internally in a structure.
Kramer (U.S. 5,193,129) introduced microbends by interweaving an optical fiber through rungs of a ladder-like structure, encapsulating it in a foam-like material, and surrounding it with a sheath. Light transmitted through the optical fiber is diminished to a value less than a threshold value upon the occurrence of microbending caused by pressure applied at any location along the length thereof. The rungs of the ladder structure are sized and spaced to provide a proper locus about which microbending may be produced. Sansone (U.S. 5,694,497) points out one of the deficiencies of this sensor by stating that it must use part of the structure it is embedded in to complete the sensor design. In fact, the utility of this type of sensor is limited in that it must be woven into the substrate or structure being measured and cannot be later repositioned as needed.
Udd et al. (U.S. 5,118,931) introduced microbends into their sensor system by melting the optical fiber and pulling simultaneously to give the fiber a smaller diameter. Lengths of this fiber were spliced into the unmelted fiber to produce the sensor. Deformation of the fiber affects propagation of light therethrough, permitting detection based upon detected changes in light throughput. As with the Kramer device, the deficiency in this design is that once spliced into the fiber, there is no way to later reposition the structure.
Sansone (U.S. 5,694,497) describes an intrinsically self deforming microbend deformer. In this device, the fiber is twisted about itself. At least one twisted section acts as an intrinsically self deforming microbend deformer. The problem with this device is that there is no way to obtain a fixed period and/or thus be able to adjust the sensitivity of the sensor.
An object of the present invention is to provide a microbend device that may 2~ bz removed and reattached to an optical fiber along its length.
Another object of the present invention is to provide a microbend device that is Fle,cible.
WO 01/53787 PCT/iJS01/02013 Another object of the present invention is to provide a sensor that employs a flexible microbend device, such that the sensor is intensity-based.
Another object of the present invention is to provide a method for using a sensor that employs a flexible microbend device, such that the method is used to measure either radial or linear forces.
SUMMARY OF THE INVENTION
By the present invention, a flexible microbend device for attachment to an optical fiber is provided. The device comprises an upper bending element grid having at least one flexible element and a lower bending element grid having at least one flexible element. Each upper bending element grid alternately engages each lower bending element grid.
When the device is attached to an optical fiber, it forms a fiber optic microbend sensor. The optical fiber is positioned between each flexible element of the upper bending element grid and each flexible element of the lower bending element grid such that each flexible element alternates between the upper and the lower bending element grids.
In use, the sensor is either attached to a surface of a structure or embedded in a host material. Optical power is introduced to the microbend sensor and the reflected light is monitored with a detector.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be obtained by means of instrumentalities in combinations particularly pointed out in the appended claims.
FIELD OF THE INVENTION
The present invention relates to fiber optic devices. In particular, it relates to a flexible microbend device that may be attached to an optical fiber and used in a sensor arrangement for measuring internal strain in a structure.
BACKGROUND OF THE INVENTION
Optical fibers are used to convey light between a light source and a light detector. Light in the fiber can be modulated by bending or otherwise distorting the fiber. This produces a modulated signal which can be picked up and processed by the light detector.
Microbend devices may be used to induce distortions in a fiber causing the light passing through the fiber to be modulated at a frequency corresponding to the force applied to the device. Typically, the device is applied to the fiber such that it surrounds the fiber.
One known device is a two jaw corrugated arrangement which squeezes an optical fiber to modulate the light signal passing therethrough. Macedo et al.
(U.S.
4,342,907) describes such a device where an upper piece is firmly connected to an enclosure by a support. A lower piece was attached to an elastic membrane.
When either a static pressure or dynamic time varying pressure reaches the membrane, it deflects pushing the lower piece, toward the upper piece, thus deforming the optical fiber which is held against the ridges of the device. They also describe another approach in U.S. 4,443,700 where two steel pieces having corrugated like surfaces with interleaving ridges form a vise which would be used to squeeze and thus deform the fiber. Such devices fail to have the compae;tness and flexibility desired for measuring forces internally in a structure.
Kramer (U.S. 5,193,129) introduced microbends by interweaving an optical fiber through rungs of a ladder-like structure, encapsulating it in a foam-like material, and surrounding it with a sheath. Light transmitted through the optical fiber is diminished to a value less than a threshold value upon the occurrence of microbending caused by pressure applied at any location along the length thereof. The rungs of the ladder structure are sized and spaced to provide a proper locus about which microbending may be produced. Sansone (U.S. 5,694,497) points out one of the deficiencies of this sensor by stating that it must use part of the structure it is embedded in to complete the sensor design. In fact, the utility of this type of sensor is limited in that it must be woven into the substrate or structure being measured and cannot be later repositioned as needed.
Udd et al. (U.S. 5,118,931) introduced microbends into their sensor system by melting the optical fiber and pulling simultaneously to give the fiber a smaller diameter. Lengths of this fiber were spliced into the unmelted fiber to produce the sensor. Deformation of the fiber affects propagation of light therethrough, permitting detection based upon detected changes in light throughput. As with the Kramer device, the deficiency in this design is that once spliced into the fiber, there is no way to later reposition the structure.
Sansone (U.S. 5,694,497) describes an intrinsically self deforming microbend deformer. In this device, the fiber is twisted about itself. At least one twisted section acts as an intrinsically self deforming microbend deformer. The problem with this device is that there is no way to obtain a fixed period and/or thus be able to adjust the sensitivity of the sensor.
An object of the present invention is to provide a microbend device that may 2~ bz removed and reattached to an optical fiber along its length.
Another object of the present invention is to provide a microbend device that is Fle,cible.
WO 01/53787 PCT/iJS01/02013 Another object of the present invention is to provide a sensor that employs a flexible microbend device, such that the sensor is intensity-based.
Another object of the present invention is to provide a method for using a sensor that employs a flexible microbend device, such that the method is used to measure either radial or linear forces.
SUMMARY OF THE INVENTION
By the present invention, a flexible microbend device for attachment to an optical fiber is provided. The device comprises an upper bending element grid having at least one flexible element and a lower bending element grid having at least one flexible element. Each upper bending element grid alternately engages each lower bending element grid.
When the device is attached to an optical fiber, it forms a fiber optic microbend sensor. The optical fiber is positioned between each flexible element of the upper bending element grid and each flexible element of the lower bending element grid such that each flexible element alternates between the upper and the lower bending element grids.
In use, the sensor is either attached to a surface of a structure or embedded in a host material. Optical power is introduced to the microbend sensor and the reflected light is monitored with a detector.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be obtained by means of instrumentalities in combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate a complete embodiment of the invention according to the best modes so far devised for the practical application of the principles thereof, and in which:
FIG. 1A is a top view of the upper bending element grid of the flexible microbend device of the present invention.
FIG. 1B is a top view of the lower bending element grid of the flexible microbend device of the present invention.
FIG. 2A depicts the assembly of the flexible microbend device.
FIG. 2B is a top view of the flexible microbend device when it is assembled.
FIG. 3 is a top view of a fiber optic microbend sensor.
FIG. 4 depicts a sensor array.
FIG. 5A depicts an optical arrangement for the fiber optic microbend sensor.
FIG. 5B depicts an alternative optical arrangement for the fiber optic 1 S microbend sensor.
FIG. 6 is side view of a fiber optic microbend sensor which is encapsulated and embedded in a host material.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures where similar elements are numbered the same throughout, FIGS. IA and IB depict the flexible microbend device 10 of the present invention. For the purpose of this specification and the appended claims, by flexible it is meant that the device can undergo a deformation without breaking. Each microbend device 10 comprises an upper bending element grid 20 and a lower 2~ bending element grid 3U. Although FIG. 1A depicts the upper bending element grid 20 and FIG. 1 B depicts the lower bending element grid 30, the two may be reversed.
Each bending element arid 2U, 3U, comprises at bast one tl~:cible element 40, 50.
Each upper flexible element 40 extends from an upper interlocking member 60, WO 01/53787 PCT/IJSOl/02013 whereas each lower flexible element 50 extends from a lower interlocking member 70.
FIGS. 1 A and 1 B depict a preferred embodiment where each bending element grid 20, 30 comprises a plurality of bending elements 40, 50. However, the invention is operable with the upper bending element grid having only one flexible element and the lower bending element grid having only one flexible element.
Each flexible element has a specific width, w, and diameter, d, and spaced apart a certain distance to form a period A. The diameter of the flexible element influences the sensitivity of the device. It was found that the flexible elements having small diameters moved more easily than those of larger diameter. Each flexible element has a stationery position at one end, or at the end where the flexible element is attacheu to the interlocking member, in order to establish a fixed period A. The period depends on whether the optical fiber used in the sensor is to be a single mode optical fiber or a multimode optical fiber. Preferably, the flexible element is prepared from a material selected from the group consisting of: a moldable plastic, 1 S micromachined silicon, an elastomer; and silica fiber. An example of silica fiber is a coated optical fiber which is cut to an appropriate length. The interlocking members are preferably prepared from a material selected from the group consisting of:
a moldable plastic, micromachined silicon, and an elastomer. If micromachined silicon is used, v-grooves are etched into the silicon to from the interlocking member.
FIG. 2A depicts how the upper bending element grid 20 is assembled with the lower bending element grid 30 to form the flexible microbend device. The upper bending element grid 20 has at least one upper interlocking member 60 positioned at an end of each flexible element :10. Similarly, the lower bending element grid 30 has at least one lower interlocking member 70 positioned at an end of each flexible 2~ element 50. When engaged, each upper interlocking member 60 of the upper bending element grid 20 mates with each respective lower flexible element 50 of the lower bending element grid 3U such that tht lower tluxiblc clement 5U nests within the upper interlocking member 60. Similarly, each lower interlocking member 70 of the lower bending element grid 30 mates with each respective upper flexible element 40 of the upper bending element grid 20 such that the upper flexible element 40 nests within the lower interlocking member 70. This allows the upper bending element grid 20 to be secured to the lower bending element grid 30. The upper and lower interlocking members 60, 70 are both depicted such that they are on the same side (or bottom) of the device when the device is assembled. However, it is understood that the upper interlocking member 60 could be positioned such that it is on a side opposite from (top side) the Lower interlocking member 70, which is on the bottom. Other configurations suitable for the particular application of interest may be used.
FIG. 2B depicts the flexible microbend device 10 after it has been assembled.
When the upper bending element grid 20 is engaged with the lo~.~er bending element grid 30, the flexible elements 40, 50 alternate. More specifically, the upper flexible element 40 is every other flexible element. Such an engagement is defined as an alternate engagement or where the upper bending element grid alternately engages the lower bending element grid.
FIG. 3 shows how the flexible microbend device 10 may be employed to form a fiber optic microbend sensor. When forming the sensor, an optical fiber 80 is positioned between each flexible element 40 of the upper bending element grid 20 and each flexible element 50 of the lower bending element grid 30. Each flexible element 40 of the upper bending element grid 20 alternately engages each flexible element 50 of the lower bending element grid 30. Note that the optical fiber 80 is sandwiched between the upper and lower flexible elements, =40 and 50, as opposed to weaving the fiber between the flexible elements.
FIG. 4 shows how a sensor array 90 is formed by attaching a plurality of 2~ flexible microbend devices 14 to an optical fiber 80. Preferably, the array is formed by a single optical fiber passing through multiple flexible microbend devices.
However, a plurality of optical fibers and fle;cible micrubend devices may be employed to form a three dimensional array or stack. In a typical application, one may have 21 flexible microbend devices attached to a single optical fiber within a thirty-foot length. The direction of sensitivity is orthogonal to the optical fiber. Either radial or linear forces are applied. As the force moves across the device, the top and bottom bending elements move up and down changing the light intensity detected by the detector.
The sensitivity may be varied by the flexible element diameter; by the number of flexible elements comprising the bending element grids; by adjusting the period A, or by changing the material properties of an encapsulating material.
The bending element grid has a stationery period. The periodic distance, A, is calculated based on the type of optical fiber used for the sensor. If the optical fiber is a multimode optical fiber, the periodic distance, A, is defined by the equation:
A = era ~~) ~2 0=n~Z-n~z 2n,~
where: a = radius of the core of the optical fiber n, = core refractive index n, = cladding refractive index.
When the optical fiber is a single mode optical fiber, the periodic distance, A, is lOpmsAs 1~OO~m. By adjusting the periodic distance, one can adjust the sensitivity of the sensor.
2~ As previously described, the flexible elements are preferably prepared from a material selected from the group consisting of: a moldable plastic;
micromachined silicon; an elastumer; anc! silic;u libm. Whcn an ulastomcr is the choice material, preferably the elastomer is a polyurethane. As a further embodiment of the invention, the sensor is encapsulated in a material having mechanical properties that are different from those of the flexible elements. For example, the encapsulated material may be selected from the group consisting of: silicone RTV; LTV-cured epoxy; an elastomer;
and polyurethane. If the sensor is to eventually be embedded in a host material, the encapsulated material must be compatible with the host material. By host material, it is understood that the material may be a material surrounding a structure such as the rubber cover on a roller. Alternatively, the sensor may be encased in a protective covering, such as a vacuum bag.
FIG. 5A depicts one optical arrangement for the fiber optic microbend sensor.
The arrangement comprises an optical coupler 100 having a first end or lead coupled to the optical fiber 80. A light source 120 is coupled to a second end or Iea.d 130 of the optical coupler 100. A detector 140 is coupled to a third end or lead 150 of the optical coupler 100. A reflector 160 is positioned at an end of the optical fiber 80 opposite from the light source 120.
FIG. 5B shows an alternate embodiment for the optical arrangement where a fused, biconical, tapered device 210 is disposed between the optical coupler 100 and the detector 140. The fused, biconical, tapered device 210 separates high and low order modes from an optical signal.
In one application, the fiber optic microbend sensor is attached to a surface of a structure. Optical power is introduced to the microbend sensor and reflected light is monitored with the detector. When the sensor is attached to the surface of a structure, the stress of force between two objects may be measured. In a second method, shown in FIG. 6, the fiber optic microbend sensor 170 is first encapsulated in a material 180 and thin embedded in a host material 190, such as a rubber roller cover, that 2~ surrounds a structure 200. Optical power is introduced and the reflected light is monitored with the detector (not shown) as a force is applied to the roller.
In this case, stress or strain on a material is detected.
_g_ The above description and drawings are only illustrative of preferred embodiments which achieve the objects, features and advantages of the present invention, and it is not intended that the present invention be limited thereto. Any modification of the present invention which comes within the spirit and scope of the following claims is considered part of the present invention.
The accompanying drawings illustrate a complete embodiment of the invention according to the best modes so far devised for the practical application of the principles thereof, and in which:
FIG. 1A is a top view of the upper bending element grid of the flexible microbend device of the present invention.
FIG. 1B is a top view of the lower bending element grid of the flexible microbend device of the present invention.
FIG. 2A depicts the assembly of the flexible microbend device.
FIG. 2B is a top view of the flexible microbend device when it is assembled.
FIG. 3 is a top view of a fiber optic microbend sensor.
FIG. 4 depicts a sensor array.
FIG. 5A depicts an optical arrangement for the fiber optic microbend sensor.
FIG. 5B depicts an alternative optical arrangement for the fiber optic 1 S microbend sensor.
FIG. 6 is side view of a fiber optic microbend sensor which is encapsulated and embedded in a host material.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures where similar elements are numbered the same throughout, FIGS. IA and IB depict the flexible microbend device 10 of the present invention. For the purpose of this specification and the appended claims, by flexible it is meant that the device can undergo a deformation without breaking. Each microbend device 10 comprises an upper bending element grid 20 and a lower 2~ bending element grid 3U. Although FIG. 1A depicts the upper bending element grid 20 and FIG. 1 B depicts the lower bending element grid 30, the two may be reversed.
Each bending element arid 2U, 3U, comprises at bast one tl~:cible element 40, 50.
Each upper flexible element 40 extends from an upper interlocking member 60, WO 01/53787 PCT/IJSOl/02013 whereas each lower flexible element 50 extends from a lower interlocking member 70.
FIGS. 1 A and 1 B depict a preferred embodiment where each bending element grid 20, 30 comprises a plurality of bending elements 40, 50. However, the invention is operable with the upper bending element grid having only one flexible element and the lower bending element grid having only one flexible element.
Each flexible element has a specific width, w, and diameter, d, and spaced apart a certain distance to form a period A. The diameter of the flexible element influences the sensitivity of the device. It was found that the flexible elements having small diameters moved more easily than those of larger diameter. Each flexible element has a stationery position at one end, or at the end where the flexible element is attacheu to the interlocking member, in order to establish a fixed period A. The period depends on whether the optical fiber used in the sensor is to be a single mode optical fiber or a multimode optical fiber. Preferably, the flexible element is prepared from a material selected from the group consisting of: a moldable plastic, 1 S micromachined silicon, an elastomer; and silica fiber. An example of silica fiber is a coated optical fiber which is cut to an appropriate length. The interlocking members are preferably prepared from a material selected from the group consisting of:
a moldable plastic, micromachined silicon, and an elastomer. If micromachined silicon is used, v-grooves are etched into the silicon to from the interlocking member.
FIG. 2A depicts how the upper bending element grid 20 is assembled with the lower bending element grid 30 to form the flexible microbend device. The upper bending element grid 20 has at least one upper interlocking member 60 positioned at an end of each flexible element :10. Similarly, the lower bending element grid 30 has at least one lower interlocking member 70 positioned at an end of each flexible 2~ element 50. When engaged, each upper interlocking member 60 of the upper bending element grid 20 mates with each respective lower flexible element 50 of the lower bending element grid 3U such that tht lower tluxiblc clement 5U nests within the upper interlocking member 60. Similarly, each lower interlocking member 70 of the lower bending element grid 30 mates with each respective upper flexible element 40 of the upper bending element grid 20 such that the upper flexible element 40 nests within the lower interlocking member 70. This allows the upper bending element grid 20 to be secured to the lower bending element grid 30. The upper and lower interlocking members 60, 70 are both depicted such that they are on the same side (or bottom) of the device when the device is assembled. However, it is understood that the upper interlocking member 60 could be positioned such that it is on a side opposite from (top side) the Lower interlocking member 70, which is on the bottom. Other configurations suitable for the particular application of interest may be used.
FIG. 2B depicts the flexible microbend device 10 after it has been assembled.
When the upper bending element grid 20 is engaged with the lo~.~er bending element grid 30, the flexible elements 40, 50 alternate. More specifically, the upper flexible element 40 is every other flexible element. Such an engagement is defined as an alternate engagement or where the upper bending element grid alternately engages the lower bending element grid.
FIG. 3 shows how the flexible microbend device 10 may be employed to form a fiber optic microbend sensor. When forming the sensor, an optical fiber 80 is positioned between each flexible element 40 of the upper bending element grid 20 and each flexible element 50 of the lower bending element grid 30. Each flexible element 40 of the upper bending element grid 20 alternately engages each flexible element 50 of the lower bending element grid 30. Note that the optical fiber 80 is sandwiched between the upper and lower flexible elements, =40 and 50, as opposed to weaving the fiber between the flexible elements.
FIG. 4 shows how a sensor array 90 is formed by attaching a plurality of 2~ flexible microbend devices 14 to an optical fiber 80. Preferably, the array is formed by a single optical fiber passing through multiple flexible microbend devices.
However, a plurality of optical fibers and fle;cible micrubend devices may be employed to form a three dimensional array or stack. In a typical application, one may have 21 flexible microbend devices attached to a single optical fiber within a thirty-foot length. The direction of sensitivity is orthogonal to the optical fiber. Either radial or linear forces are applied. As the force moves across the device, the top and bottom bending elements move up and down changing the light intensity detected by the detector.
The sensitivity may be varied by the flexible element diameter; by the number of flexible elements comprising the bending element grids; by adjusting the period A, or by changing the material properties of an encapsulating material.
The bending element grid has a stationery period. The periodic distance, A, is calculated based on the type of optical fiber used for the sensor. If the optical fiber is a multimode optical fiber, the periodic distance, A, is defined by the equation:
A = era ~~) ~2 0=n~Z-n~z 2n,~
where: a = radius of the core of the optical fiber n, = core refractive index n, = cladding refractive index.
When the optical fiber is a single mode optical fiber, the periodic distance, A, is lOpmsAs 1~OO~m. By adjusting the periodic distance, one can adjust the sensitivity of the sensor.
2~ As previously described, the flexible elements are preferably prepared from a material selected from the group consisting of: a moldable plastic;
micromachined silicon; an elastumer; anc! silic;u libm. Whcn an ulastomcr is the choice material, preferably the elastomer is a polyurethane. As a further embodiment of the invention, the sensor is encapsulated in a material having mechanical properties that are different from those of the flexible elements. For example, the encapsulated material may be selected from the group consisting of: silicone RTV; LTV-cured epoxy; an elastomer;
and polyurethane. If the sensor is to eventually be embedded in a host material, the encapsulated material must be compatible with the host material. By host material, it is understood that the material may be a material surrounding a structure such as the rubber cover on a roller. Alternatively, the sensor may be encased in a protective covering, such as a vacuum bag.
FIG. 5A depicts one optical arrangement for the fiber optic microbend sensor.
The arrangement comprises an optical coupler 100 having a first end or lead coupled to the optical fiber 80. A light source 120 is coupled to a second end or Iea.d 130 of the optical coupler 100. A detector 140 is coupled to a third end or lead 150 of the optical coupler 100. A reflector 160 is positioned at an end of the optical fiber 80 opposite from the light source 120.
FIG. 5B shows an alternate embodiment for the optical arrangement where a fused, biconical, tapered device 210 is disposed between the optical coupler 100 and the detector 140. The fused, biconical, tapered device 210 separates high and low order modes from an optical signal.
In one application, the fiber optic microbend sensor is attached to a surface of a structure. Optical power is introduced to the microbend sensor and reflected light is monitored with the detector. When the sensor is attached to the surface of a structure, the stress of force between two objects may be measured. In a second method, shown in FIG. 6, the fiber optic microbend sensor 170 is first encapsulated in a material 180 and thin embedded in a host material 190, such as a rubber roller cover, that 2~ surrounds a structure 200. Optical power is introduced and the reflected light is monitored with the detector (not shown) as a force is applied to the roller.
In this case, stress or strain on a material is detected.
_g_ The above description and drawings are only illustrative of preferred embodiments which achieve the objects, features and advantages of the present invention, and it is not intended that the present invention be limited thereto. Any modification of the present invention which comes within the spirit and scope of the following claims is considered part of the present invention.
Claims (18)
1. A flexible microbend device for attachment to an optical fiber, the device comprising:
an upper bending element grid having at least one flexible element;
a lower bending element grid having at least one flexible element; and wherein each flexible element of the upper bending element grid alternately engages each flexible element of the lower bending element grid.
an upper bending element grid having at least one flexible element;
a lower bending element grid having at least one flexible element; and wherein each flexible element of the upper bending element grid alternately engages each flexible element of the lower bending element grid.
2. A flexible microbend device according to claim 1, wherein the upper bending element grid has at least one upper interlocking member positioned at an end of each flexible element; and wherein the lower bending element grid has at least one lower interlocking member positioned at an end of each flexible element; wherein each upper interlocking member of the upper bending element grid mates with each respective lower flexible element of the lower bending element grid and wherein each lower interlocking member of the lower bending element grid mates with each respective upper flexible element of the upper bending element grid to secure the upper bending element grid to the lower bending element grid.
3. A flexible microbend device according to claim 1, wherein each flexible element is prepared from a material selected from the group consisting of: a moldable plastic; micromachined silicon; an elastomer; and silica fiber.
4. A flexible microbend device according to claim 3, wherein the silica fiber is a coated optical fiber.
5. A fiber optic microbend sensor comprising:
a flexible microbend device comprising an upper bending element grid having at least one flexible element; and a lower bending element grid having at least one flexible element;
an optical fiber positioned between each flexible element of the upper bending element grid and each flexible element of the lower bending element grid; and wherein each flexible element of the upper bending element grid alternately engages each flexible element of the lower bending element grid to form a sensor.
a flexible microbend device comprising an upper bending element grid having at least one flexible element; and a lower bending element grid having at least one flexible element;
an optical fiber positioned between each flexible element of the upper bending element grid and each flexible element of the lower bending element grid; and wherein each flexible element of the upper bending element grid alternately engages each flexible element of the lower bending element grid to form a sensor.
6. A fiber optic microbend sensor according to claim 5, wherein a plurality of flexible microbend devices are attached to an optical fiber to form a sensor array
7. A fiber optic microbend sensor according to claim 5, wherein the optical fiber is a multimode optical fiber and wherein each upper bending element grid and each lower bending element grid each comprise a plurality of flexible elements, each flexible element spaced apart by a periodic distance A, wherein .LAMBDA. is defined by the equation:
where: a = radius of the core of the optical fiber n1 = core refractive index n2 = cladding refractive index.
where: a = radius of the core of the optical fiber n1 = core refractive index n2 = cladding refractive index.
8. A fiber optic microbend sensor according to claim 5, wherein each flexible element is prepared from a material selected from the group consisting of a moldable plastic; micromachined silicon; an elastomer; and silica fiber.
9. A fiber optic microbend sensor according to claim 8, wherein the elastomer is a polyurethane.
10. A fiber optic microbend sensor according to claim 5, wherein the sensor is encapsulated in a material having mechanical properties that are different from those of the flexible elements.
11. A fiber optic microbend sensor according to claim 10, wherein the encapsulated material is selected from the group consisting of silicone RTV;
UV-cured epoxy; an elastomer; and polyurethane.
UV-cured epoxy; an elastomer; and polyurethane.
12. A fiber optic microbend sensor according to claim 5, wherein the sensor is encased in a protective covering.
13. A fiber optic microbend sensor according to claim 12, wherein the protective covering is a vacuum bag.
14. A fiber optic microbend sensor according to claim 5, wherein the optical fiber is a single mode optical fiber and wherein each upper bending element grid and each lower bending element grid each comprise a plurality of flexible elements, each flexible element is spaced apart by a periodic distance A, where 10µ<=.LAMBDA.<=1500µm.
15. A fiber optic microbend sensor according to claim 5, further comprising:
an optical coupler having a first end coupled to the optical fiber;
a light source coupled to a second end of the optical coupler;
a detector coupled to a third end of the optical coupler; and a reflector positioned at an end of the optical fiber opposite from the light source.
an optical coupler having a first end coupled to the optical fiber;
a light source coupled to a second end of the optical coupler;
a detector coupled to a third end of the optical coupler; and a reflector positioned at an end of the optical fiber opposite from the light source.
16. A fiber optic microbend sensor according to claim 15, further comprising a fused, biconical, tapered device disposed between the optical coupler and the detector, wherein the fused, biconical, tapered device separates high and low order modes from an optical signal.
17. A method for using the fiber optic microbend sensor according to claim 15, the method comprising the steps of a) providing a fiber optic microbend sensor;
b) attaching the sensor to a surface of a structure;
c) introducing optical power to the microbend sensor; and d) monitoring reflected light with the detector.
b) attaching the sensor to a surface of a structure;
c) introducing optical power to the microbend sensor; and d) monitoring reflected light with the detector.
18. A method for using the fiber optic microbend sensor according to claim 15, the method comprising the steps of:
a) providing the microbend sensor;
b) embedding the sensor in a host material;
c) introducing optical power to the microbend sensor; and d) monitoring reflected light with the detector.
a) providing the microbend sensor;
b) embedding the sensor in a host material;
c) introducing optical power to the microbend sensor; and d) monitoring reflected light with the detector.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/489,768 | 2000-01-21 | ||
US09/489,768 US6429421B1 (en) | 2000-01-21 | 2000-01-21 | Flexible fiber optic microbend device, with interlocking flexible fibers, sensors, and method use |
PCT/US2001/002013 WO2001053787A1 (en) | 2000-01-21 | 2001-01-19 | Flexible fiber optic microbend device, sensors, and method of use |
Publications (1)
Publication Number | Publication Date |
---|---|
CA2386348A1 true CA2386348A1 (en) | 2001-07-26 |
Family
ID=23945184
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002386348A Abandoned CA2386348A1 (en) | 2000-01-21 | 2001-01-19 | Flexible fiber optic microbend device, sensors, and method of use |
Country Status (13)
Country | Link |
---|---|
US (1) | US6429421B1 (en) |
EP (1) | EP1254354B1 (en) |
JP (1) | JP2003520956A (en) |
KR (1) | KR20020073479A (en) |
CN (1) | CN1395680A (en) |
AT (1) | ATE329237T1 (en) |
AU (1) | AU2001234502A1 (en) |
BR (1) | BR0107143A (en) |
CA (1) | CA2386348A1 (en) |
DE (1) | DE60120358T2 (en) |
MX (1) | MXPA02003824A (en) |
NO (1) | NO325411B1 (en) |
WO (1) | WO2001053787A1 (en) |
Families Citing this family (76)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6621948B1 (en) * | 2002-06-04 | 2003-09-16 | Raytheon Company | Apparatus and method for differential output optical fiber displacement sensing |
US6981935B2 (en) * | 2002-09-12 | 2006-01-03 | Stowe Woodward, L.L.C. | Suction roll with sensors for detecting temperature and/or pressure |
DE10251085B4 (en) * | 2002-10-29 | 2004-12-09 | Decoma (Germany) Gmbh | Multi-layer sensor |
US6983096B2 (en) * | 2003-04-15 | 2006-01-03 | Intel Corporation | Attenuation of cladding modes in optical fibers |
US6874232B2 (en) | 2003-05-21 | 2005-04-05 | Stowe Woodward, Llc | Method for forming cover for industrial roll |
JP4568145B2 (en) * | 2005-03-08 | 2010-10-27 | 日立電線株式会社 | Shock detecting optical fiber sensor, load concentrating plate and manufacturing method thereof |
US7572214B2 (en) | 2005-05-04 | 2009-08-11 | Stowe Woodward L.L.C. | Suction roll with sensors for detecting operational parameters having apertures |
CN100360905C (en) * | 2005-09-29 | 2008-01-09 | 上海交通大学 | Optical fiber micro-bending displacement sensor |
US10287731B2 (en) | 2005-11-08 | 2019-05-14 | Stowe Woodward Licensco Llc | Abrasion-resistant rubber roll cover with polyurethane coating |
US9867530B2 (en) | 2006-08-14 | 2018-01-16 | Volcano Corporation | Telescopic side port catheter device with imaging system and method for accessing side branch occlusions |
WO2009009799A1 (en) | 2007-07-12 | 2009-01-15 | Volcano Corporation | Catheter for in vivo imaging |
WO2009009802A1 (en) | 2007-07-12 | 2009-01-15 | Volcano Corporation | Oct-ivus catheter for concurrent luminal imaging |
US9596993B2 (en) | 2007-07-12 | 2017-03-21 | Volcano Corporation | Automatic calibration systems and methods of use |
US9097595B2 (en) | 2008-11-14 | 2015-08-04 | Stowe Woodward, L.L.C. | System and method for detecting and measuring vibration in an industrial roll |
US8346501B2 (en) | 2009-06-22 | 2013-01-01 | Stowe Woodward, L.L.C. | Industrial roll with sensors arranged to self-identify angular location |
US8236141B2 (en) | 2009-06-23 | 2012-08-07 | Stowe Woodward, L.L.C. | Industrial roll with sensors having conformable conductive sheets |
US10555691B2 (en) | 2009-08-06 | 2020-02-11 | Agency For Science Technology And Research | Vital signs detecting device and a method for detecting vital signs |
US8475347B2 (en) | 2010-06-04 | 2013-07-02 | Stowe Woodward Licensco, Llc | Industrial roll with multiple sensor arrays |
US11141063B2 (en) | 2010-12-23 | 2021-10-12 | Philips Image Guided Therapy Corporation | Integrated system architectures and methods of use |
US11040140B2 (en) | 2010-12-31 | 2021-06-22 | Philips Image Guided Therapy Corporation | Deep vein thrombosis therapeutic methods |
US9360630B2 (en) | 2011-08-31 | 2016-06-07 | Volcano Corporation | Optical-electrical rotary joint and methods of use |
AU2013209881B2 (en) | 2012-01-17 | 2015-04-30 | Stowe Woodward Licensco, Llc | System and method of determining the angular position of a rotating roll |
US9588582B2 (en) | 2013-09-17 | 2017-03-07 | Medibotics Llc | Motion recognition clothing (TM) with two different sets of tubes spanning a body joint |
US9582072B2 (en) | 2013-09-17 | 2017-02-28 | Medibotics Llc | Motion recognition clothing [TM] with flexible electromagnetic, light, or sonic energy pathways |
US10602965B2 (en) | 2013-09-17 | 2020-03-31 | Medibotics | Wearable deformable conductive sensors for human motion capture including trans-joint pitch, yaw, and roll |
US10716510B2 (en) | 2013-09-17 | 2020-07-21 | Medibotics | Smart clothing with converging/diverging bend or stretch sensors for measuring body motion or configuration |
US10321873B2 (en) | 2013-09-17 | 2019-06-18 | Medibotics Llc | Smart clothing for ambulatory human motion capture |
US10568586B2 (en) | 2012-10-05 | 2020-02-25 | Volcano Corporation | Systems for indicating parameters in an imaging data set and methods of use |
US10070827B2 (en) | 2012-10-05 | 2018-09-11 | Volcano Corporation | Automatic image playback |
US9307926B2 (en) | 2012-10-05 | 2016-04-12 | Volcano Corporation | Automatic stent detection |
US11272845B2 (en) | 2012-10-05 | 2022-03-15 | Philips Image Guided Therapy Corporation | System and method for instant and automatic border detection |
US9292918B2 (en) | 2012-10-05 | 2016-03-22 | Volcano Corporation | Methods and systems for transforming luminal images |
US9324141B2 (en) | 2012-10-05 | 2016-04-26 | Volcano Corporation | Removal of A-scan streaking artifact |
US9858668B2 (en) | 2012-10-05 | 2018-01-02 | Volcano Corporation | Guidewire artifact removal in images |
US9367965B2 (en) | 2012-10-05 | 2016-06-14 | Volcano Corporation | Systems and methods for generating images of tissue |
US9286673B2 (en) | 2012-10-05 | 2016-03-15 | Volcano Corporation | Systems for correcting distortions in a medical image and methods of use thereof |
JP2015532536A (en) | 2012-10-05 | 2015-11-09 | デイビッド ウェルフォード, | System and method for amplifying light |
US9840734B2 (en) | 2012-10-22 | 2017-12-12 | Raindance Technologies, Inc. | Methods for analyzing DNA |
EP2931132B1 (en) | 2012-12-13 | 2023-07-05 | Philips Image Guided Therapy Corporation | System for targeted cannulation |
EP2934310A4 (en) | 2012-12-20 | 2016-10-12 | Nathaniel J Kemp | Optical coherence tomography system that is reconfigurable between different imaging modes |
US10939826B2 (en) | 2012-12-20 | 2021-03-09 | Philips Image Guided Therapy Corporation | Aspirating and removing biological material |
US10942022B2 (en) | 2012-12-20 | 2021-03-09 | Philips Image Guided Therapy Corporation | Manual calibration of imaging system |
CA2895770A1 (en) | 2012-12-20 | 2014-07-24 | Jeremy Stigall | Locating intravascular images |
WO2014099899A1 (en) | 2012-12-20 | 2014-06-26 | Jeremy Stigall | Smooth transition catheters |
US11406498B2 (en) | 2012-12-20 | 2022-08-09 | Philips Image Guided Therapy Corporation | Implant delivery system and implants |
US10413317B2 (en) | 2012-12-21 | 2019-09-17 | Volcano Corporation | System and method for catheter steering and operation |
EP2934280B1 (en) | 2012-12-21 | 2022-10-19 | Mai, Jerome | Ultrasound imaging with variable line density |
EP2936426B1 (en) | 2012-12-21 | 2021-10-13 | Jason Spencer | System and method for graphical processing of medical data |
US10058284B2 (en) | 2012-12-21 | 2018-08-28 | Volcano Corporation | Simultaneous imaging, monitoring, and therapy |
US9612105B2 (en) | 2012-12-21 | 2017-04-04 | Volcano Corporation | Polarization sensitive optical coherence tomography system |
EP2934323A4 (en) | 2012-12-21 | 2016-08-17 | Andrew Hancock | System and method for multipath processing of image signals |
CA2896006A1 (en) | 2012-12-21 | 2014-06-26 | David Welford | Systems and methods for narrowing a wavelength emission of light |
US9486143B2 (en) | 2012-12-21 | 2016-11-08 | Volcano Corporation | Intravascular forward imaging device |
WO2014100162A1 (en) | 2012-12-21 | 2014-06-26 | Kemp Nathaniel J | Power-efficient optical buffering using optical switch |
WO2014100606A1 (en) | 2012-12-21 | 2014-06-26 | Meyer, Douglas | Rotational ultrasound imaging catheter with extended catheter body telescope |
US10226597B2 (en) | 2013-03-07 | 2019-03-12 | Volcano Corporation | Guidewire with centering mechanism |
US9770172B2 (en) | 2013-03-07 | 2017-09-26 | Volcano Corporation | Multimodal segmentation in intravascular images |
EP2967391A4 (en) | 2013-03-12 | 2016-11-02 | Donna Collins | Systems and methods for diagnosing coronary microvascular disease |
US11154313B2 (en) | 2013-03-12 | 2021-10-26 | The Volcano Corporation | Vibrating guidewire torquer and methods of use |
US9301687B2 (en) | 2013-03-13 | 2016-04-05 | Volcano Corporation | System and method for OCT depth calibration |
US11026591B2 (en) | 2013-03-13 | 2021-06-08 | Philips Image Guided Therapy Corporation | Intravascular pressure sensor calibration |
US10758207B2 (en) | 2013-03-13 | 2020-09-01 | Philips Image Guided Therapy Corporation | Systems and methods for producing an image from a rotational intravascular ultrasound device |
US10292677B2 (en) | 2013-03-14 | 2019-05-21 | Volcano Corporation | Endoluminal filter having enhanced echogenic properties |
US10219887B2 (en) | 2013-03-14 | 2019-03-05 | Volcano Corporation | Filters with echogenic characteristics |
US20160030151A1 (en) | 2013-03-14 | 2016-02-04 | Volcano Corporation | Filters with echogenic characteristics |
JP6134436B2 (en) | 2013-04-19 | 2017-05-24 | ストウ・ウッドワード・ライセンスコ,リミテッド・ライアビリティ・カンパニー | Method and system for determining the rotational position of an industrial roll |
CN103852089B (en) * | 2014-03-29 | 2017-02-15 | 吉林大学 | Plastic optical fiber sensor with multi-tapered hole bent structure |
CN104034456B (en) * | 2014-04-15 | 2016-04-13 | 南昌大学 | The optical fiber macrobend anamorphoser of adjustable bending radius |
CN104019928B (en) * | 2014-06-24 | 2015-12-30 | 黑龙江工程学院 | Seriation cushion layer structure optical fiber micro-bending sensor |
US9650744B2 (en) | 2014-09-12 | 2017-05-16 | Stowe Woodward Licensco Llc | Suction roll with sensors for detecting operational parameters |
JP7171432B2 (en) * | 2015-10-02 | 2022-11-15 | コーニンクレッカ フィリップス エヌ ヴェ | Hub for device navigation with optical shape-sensing guidewires |
MX2018009154A (en) | 2016-04-26 | 2018-11-09 | Stowe Woodward Licensco Llc | Suction roll with pattern of through holes and blind drilled holes that improves land distance. |
GB2567610B (en) * | 2017-03-21 | 2021-07-21 | Nuron Ltd | Optical fibre pressure sensing apparatus employing longitudinal diaphragm |
US10837804B2 (en) | 2018-06-28 | 2020-11-17 | Corning Incorporated | Enhanced microbend sensor |
CN110652054B (en) * | 2018-06-29 | 2021-07-02 | 深圳市掌网科技股份有限公司 | Joint protector, joint protector control system and method |
CN109405761A (en) * | 2018-11-14 | 2019-03-01 | 深圳市迈步机器人科技有限公司 | Fibre optical sensor, deformation detecting device, detection method and data glove |
Family Cites Families (40)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3891302A (en) | 1973-09-28 | 1975-06-24 | Western Electric Co | Method of filtering modes in optical waveguides |
US4342907A (en) | 1977-12-12 | 1982-08-03 | Pedro B. Macedo | Optical sensing apparatus and method |
US4443700A (en) | 1980-02-01 | 1984-04-17 | Pedro B. Macedo | Optical sensing apparatus and method |
US4927232A (en) | 1985-03-18 | 1990-05-22 | G2 Systems Corporation | Structural monitoring system using fiber optics |
US4459477A (en) | 1981-08-27 | 1984-07-10 | Trw Inc. | Microbending of optical fibers for remote force measurement |
US4421979A (en) | 1981-08-27 | 1983-12-20 | Trw Inc. | Microbending of optical fibers for remote force measurement |
US4449210A (en) | 1981-12-21 | 1984-05-15 | Hughes Aircraft Company | Fiber optic hydrophone transducers |
US4530078A (en) | 1982-06-11 | 1985-07-16 | Nicholas Lagakos | Microbending fiber optic acoustic sensor |
US4488040A (en) | 1982-11-19 | 1984-12-11 | Gte Products Corporation | Fiber optic sensor |
GB2155621B (en) | 1984-03-06 | 1988-01-06 | Standard Telephones Cables Ltd | Optical fibre sensors |
SE443656B (en) | 1984-07-20 | 1986-03-03 | Ericsson Telefon Ab L M | MICROBOOK LIKE OPTICAL FIBER CABLE |
US4678903A (en) | 1986-01-27 | 1987-07-07 | General Motors Corporation | Self aligning fiber optic microbend sensor |
US4871908A (en) | 1986-02-03 | 1989-10-03 | The Babcock & Wilcox Company | Overload protection for fiber optic microbend sensor |
CH666552A5 (en) | 1986-03-06 | 1988-07-29 | Suisse Electronique Microtech | MICRO-CURVED FIBER OPTIC SENSOR. |
US4830461A (en) | 1987-01-29 | 1989-05-16 | Bridgestone Corporation | Pressure-sensitive sensors |
US4891511A (en) | 1988-08-31 | 1990-01-02 | The Babcock & Wilcox Co. | Fiber optic microbend sensor with braided fibers |
FR2637080B1 (en) * | 1988-09-27 | 1990-11-09 | Labo Electronique Physique | FIBER OPTIC PRESSURE SENSOR |
US5013908A (en) | 1988-11-28 | 1991-05-07 | Kaman Sciences Corporation | Break detection system using optical fibers having unique frequency modulated light |
US4924970A (en) | 1989-03-09 | 1990-05-15 | Seals William L | Ladder apparatus |
US4932263A (en) | 1989-06-26 | 1990-06-12 | General Motors Corporation | Temperature compensated fiber optic pressure sensor |
US4932262A (en) | 1989-06-26 | 1990-06-12 | General Motors Corporation | Miniature fiber optic pressure sensor |
US5118931A (en) | 1990-09-07 | 1992-06-02 | Mcdonnell Douglas Corporation | Fiber optic microbending sensor arrays including microbend sensors sensitive over different bands of wavelengths of light |
US5196694A (en) * | 1991-05-13 | 1993-03-23 | The Babcock & Wilcox Company | Temperature compensated self-referenced fiber optic microbend pressure transducer |
US5193129A (en) | 1991-09-27 | 1993-03-09 | Rockwell International Corporation | Pressure sensor utilizing microbending of a fiber optic cable woven through a ladder shaped structure |
FR2686707B1 (en) | 1992-01-29 | 1994-03-18 | Alcatel Cable | PROCESS FOR OBTAINING A PRE-STRESSED FIBER OPTIC SENSOR AND DEVICE FOR IMPLEMENTING SAME. |
FR2689234B1 (en) | 1992-03-26 | 1994-07-01 | Opto Ind | IMPROVED FIBER OPTIC PRESSURE SENSOR. |
US5260566A (en) | 1992-06-12 | 1993-11-09 | The Babcock & Wilcox Company | Self-powered fiber optic microbend sensors |
US5421195A (en) | 1993-07-01 | 1995-06-06 | Wlodarczyk; Marek T. | Fiber optic microbend sensor for engine knock and misfire detection |
US5419636A (en) | 1993-08-12 | 1995-05-30 | Sandia Corporation | Microbend fiber-optic temperature sensor |
US5714680A (en) | 1993-11-04 | 1998-02-03 | The Texas A&M University System | Method and apparatus for measuring pressure with fiber optics |
US5411566A (en) | 1994-06-08 | 1995-05-02 | At&T Corp. | Optical fiber spatial mode converter using periodic core deformation |
US5592875A (en) | 1994-09-16 | 1997-01-14 | Stowe Woodward Licensco, Inc. | Roll having means for determining pressure distribution |
US5562027A (en) | 1995-02-16 | 1996-10-08 | Stowe Woodward Licensco, Inc. | Dynamic nip pressure and temperature sensing system |
FR2733591B1 (en) * | 1995-04-26 | 1997-06-13 | Honeywell | PRESSURE SENSITIVE OPTICAL DEVICE AND PRESENCE DETECTION FLOOR |
US5600125A (en) | 1995-05-16 | 1997-02-04 | Poorman; Thomas J. | Compensation and status monitoring devices for fiber optic intensity-modulated sensors |
US5694497A (en) | 1995-06-19 | 1997-12-02 | The United States Of America As Represented By The Secretary Of The Navy | Intrinsically self deforming fiber optic microbend pressure and strain sensor |
DE19534260C2 (en) * | 1995-09-15 | 2002-07-04 | Friedrich Motzko | Rope-shaped fiber optic load sensor |
US5684912A (en) * | 1995-10-18 | 1997-11-04 | Fico, Inc. | Optical fiber signal attenuator |
US5913245A (en) * | 1997-07-07 | 1999-06-15 | Grossman; Barry G. | Flexible optical fiber sensor tapes, systems and methods |
FR2769379B1 (en) * | 1997-10-03 | 2000-02-11 | France Telecom | DEVICE FOR THE OPERATION AND MAINTENANCE OF FIBER OPTIC NETWORKS |
-
2000
- 2000-01-21 US US09/489,768 patent/US6429421B1/en not_active Expired - Lifetime
-
2001
- 2001-01-19 CA CA002386348A patent/CA2386348A1/en not_active Abandoned
- 2001-01-19 KR KR1020027007091A patent/KR20020073479A/en not_active Application Discontinuation
- 2001-01-19 AU AU2001234502A patent/AU2001234502A1/en not_active Abandoned
- 2001-01-19 JP JP2001554028A patent/JP2003520956A/en active Pending
- 2001-01-19 WO PCT/US2001/002013 patent/WO2001053787A1/en active IP Right Grant
- 2001-01-19 EP EP01906613A patent/EP1254354B1/en not_active Expired - Lifetime
- 2001-01-19 CN CN01803996A patent/CN1395680A/en active Pending
- 2001-01-19 MX MXPA02003824A patent/MXPA02003824A/en active IP Right Grant
- 2001-01-19 DE DE60120358T patent/DE60120358T2/en not_active Expired - Lifetime
- 2001-01-19 AT AT01906613T patent/ATE329237T1/en not_active IP Right Cessation
- 2001-01-19 BR BR0107143-2A patent/BR0107143A/en not_active IP Right Cessation
-
2002
- 2002-04-08 NO NO20021655A patent/NO325411B1/en unknown
Also Published As
Publication number | Publication date |
---|---|
NO20021655L (en) | 2002-07-19 |
DE60120358T2 (en) | 2006-10-12 |
US6429421B1 (en) | 2002-08-06 |
EP1254354B1 (en) | 2006-06-07 |
EP1254354A1 (en) | 2002-11-06 |
CN1395680A (en) | 2003-02-05 |
NO20021655D0 (en) | 2002-04-08 |
WO2001053787A1 (en) | 2001-07-26 |
BR0107143A (en) | 2002-07-02 |
KR20020073479A (en) | 2002-09-26 |
NO325411B1 (en) | 2008-04-21 |
DE60120358D1 (en) | 2006-07-20 |
ATE329237T1 (en) | 2006-06-15 |
AU2001234502A1 (en) | 2001-07-31 |
MXPA02003824A (en) | 2003-09-25 |
JP2003520956A (en) | 2003-07-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6429421B1 (en) | Flexible fiber optic microbend device, with interlocking flexible fibers, sensors, and method use | |
EP0702780B1 (en) | Fiber optic bending and positioning sensor | |
US5633494A (en) | Fiber optic bending and positioning sensor with selected curved light emission surfaces | |
CA1270662A (en) | Optical sensor | |
EP0034181B1 (en) | Fiber optic strain sensor | |
CN101943568B (en) | Fiber strain sensor and measurement system for repeated large deformation | |
US8886001B2 (en) | Sensing device having a large diameter D-shaped optical waveguide | |
WO2011120147A1 (en) | Multi-point pressure sensor and uses thereof | |
US5694497A (en) | Intrinsically self deforming fiber optic microbend pressure and strain sensor | |
GB2459975A (en) | Optical fibre sensor | |
US7050662B2 (en) | Fiber Bragg grating compression sensor system | |
Heo et al. | Tactile sensors using the distributed optical fiber sensors | |
CN214066388U (en) | Sensing optical unit and cable | |
EP4165383A1 (en) | Two-dimensional optical waveguide pressure sensor array | |
Yamazaki et al. | Optical strain gauge-based on a hetero-core fiber macro-bending sensor | |
EP3850311B1 (en) | Fibre optic cables | |
Xu et al. | Stretchable multi-function fiber sensor for tension, bending and torsion sensing | |
KR100301776B1 (en) | Ribbon type optical sensor for measuring deformation of institution | |
WO1988005905A1 (en) | A measuring device for the determination of deformations, relative movements or the like | |
US6718078B2 (en) | High sensitivity fiber optic rotation sensor | |
Heo et al. | Development of flexible force sensors using fiber Bragg grating for tactile sensing and its evaluation | |
CA2454970C (en) | Sensing device having a large diameter d-shaped optical waveguide | |
Heo et al. | Development of the Tactile Sensor System Using Fiber Bragg Grating Sensors | |
Tao et al. | Experimental research on the effect of Young's modulus on optical fiber microbend strain sensor | |
Kelb et al. | A Simple Polymer-Optical Tilt and Displacement Sensor |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
EEER | Examination request | ||
FZDE | Discontinued |