Fiber shape sensing systems and methods
First Claim
Patent Images
1. A shape measuring system comprising:
- a large core optical fiber wherein a fiber grating is written onto said optical fiber; and
a spectral read out system configured to measure a property of a reflection of light from the fiber grating,wherein the optical fiber includes a fiber core and a fiber cladding, and wherein a separation between outer opposite edges of the diameter of the fiber core is configured such that when the optical fiber is bent, a strain difference exists between the outer opposite edges across the fiber core, and wherein the strain difference in the optical fiber is used to determine bend and/or twisting measurements of the optical fiber.
4 Assignments
0 Petitions
Accused Products
Abstract
In certain variations, fiber shape sensing or measuring systems, devices and methods are described herein, which allow for measurement of three dimensional bending as well as twist measurements of various fibers, e.g., optical fibers and fiber optic probes of various sizes. In certain variations, the systems are designed to take advantage of unique light guiding properties of optical fibers and various fiber gratings.
-
Citations
68 Claims
-
1. A shape measuring system comprising:
-
a large core optical fiber wherein a fiber grating is written onto said optical fiber; and a spectral read out system configured to measure a property of a reflection of light from the fiber grating, wherein the optical fiber includes a fiber core and a fiber cladding, and wherein a separation between outer opposite edges of the diameter of the fiber core is configured such that when the optical fiber is bent, a strain difference exists between the outer opposite edges across the fiber core, and wherein the strain difference in the optical fiber is used to determine bend and/or twisting measurements of the optical fiber. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20)
-
-
16. A system for measuring twist comprising:
-
a light beam director; an optical fiber having a first reference tilted fiber grating, a second tilted fiber grating and an end reflector, wherein the optical fiber has birefringent axes and wherein the first reference tilted fiber grating is positioned at a location where twist of the optical fiber is known, and wherein the second tilted fiber grating is disposed along an axis that is between the birefringent axes; a polarizer; and at least one output spectrometer, wherein the light beam director is configured to receive a light beam such that at least a portion of the light beam is directed from the light beam director into the optical fiber, the end reflector being configured to reflect the at least a portion of the light beam back through the tilted fiber gratings to the light beam director, through the polarizer and onto the at least one output spectrometer to detect a polarization state of a wavelength associated with the second tilted fiber grating to measure twist along the optical fiber at points associated with the second tilted fiber grating. - View Dependent Claims (17, 18, 19, 21, 22, 23, 24, 25, 26)
-
-
27. A method for measuring twist along a fiber comprising:
-
coupling a light beam into a light beam director; directing at least a portion of the light beam from the light beam director into an optical fiber, the optical fiber having a first reference tilted fiber grating, a second tilted fiber grating and an end reflector, wherein the optical fiber has birefringent axes and wherein the first reference tilted fiber grating is positioned at a location where twist of the optical fiber is known, and wherein the second tilted fiber grating is disposed along an axis that is between the birefringent axes; reflecting the light beam back through the tilted fiber gratings to the light beam director, through a polarizer and onto at least one spectrometer; and detecting a polarization state of a wavelength associated with the second tilted fiber grating to measure twist along a region of the fiber associated with the second tilted fiber grating. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
-
-
38. A system for measuring twist comprising:
-
a light beam director; an optical fiber having a birefringent fiber grating; a polarizer; and a spectrometer, wherein the light beam director is configured to receive a light beam such that at least a portion of the light beam is directed from the light beam director to the birefringent fiber grating of the optical fiber, the birefringent fiber grating being configured to at least partially reflect the light beam back to the light beam director, which directs the light beam through the polarizer and onto the spectrometer, wherein reflection spectra of the birefringent fiber grating is split into two distinct spectral peaks that are polarization dependent; wherein relative amplitudes of the spectral peaks are detected to measure twist along the optical fiber; and wherein a change in the ratio of the relative amplitudes of the spectral peaks are detected to measure twist along the optical fiber. - View Dependent Claims (39, 40, 41, 42, 43, 44, 45)
-
-
46. A method for measuring twist along a fiber comprising:
-
coupling a light beam into a light beam director; directing at least a portion of the light beam from the light beam director into an optical fiber, the optical fiber having a birefringent fiber grating; reflecting at least a portion of the light beam off of the birefringent fiber grating toward the light beam director, through a polarizer and onto a spectrometer; splitting a reflection spectra of the fiber grating into two distinct spectral peaks that are polarization dependent; and detecting the relative amplitudes and change in their ratio to measure twist along the fiber. - View Dependent Claims (47, 48, 49, 50, 51, 52, 53)
-
-
54. A method of sensing a shape of an optical fiber comprising:
-
directing at least a portion of a light beam into an optical fiber, the optical fiber having a first reference tilted fiber grating and a second tilted fiber grating, wherein the optical fiber has birefringent axes and wherein the first reference tilted fiber grating is positioned at a location where twist of the optical fiber is known, and wherein the second tilted fiber grating is disposed along an axis that is between the birefringent axes; reflecting the light beam back through the tilted fiber gratings, through a polarizing beam splitter and onto a detector; and detecting a degree of polarization for each wavelength associated with the second tilted fiber grating to measure twist along a region of the optical fiber associated with the second tilted fiber grating. - View Dependent Claims (55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68)
-
Specification