US4371838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical fiber waveguide for measuring magnetic fields
Assignee: United States Department of the Navy
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Filing: 1980-09-24
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Granted: 1983-02-01
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Expires: 2000-09-24
Abstract
Abstract An optical fiber waveguide for detecting magnetic fields. The optical fiber waveguide includes therein an array of discrete elongate magnetized particles, all polarized in the same direction with their axes generally parallel with the longitudinal axis of the waveguide, which in the presence of a time-varying magnetic field are subjected to magnetostrictive effects and undergo linear dimension changes to cause a related longitudinal dimension change of the optical fiber waveguide whereby a laser beam passing longitudinally through the waveguide is subject to phase shifts detectable by interferometry.
Inventors
- 👤 David L. Griscom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:19
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/09; G02F1/095; G01; G01R; G01R33/00; G01R33/02; G01R33/032; G01R33/0327; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/842; Y10S505/843; Y10S505/845
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
134 words
An optical fiber waveguide for use in the detection of a magnetic field or magnetic radiation accompanying an electromagnetic signal comprising: an optical fiber waveguide including numerous discrete elongate single-domain magnetized particles; said particles having their longitudinal axes and magnetization vectors disposed generally parallel with the longitudinal axis of the waveguide; a laser with its beam directed into one end of said waveguide; interferometric means for sensing phase shifts in the light of said laser passing through said waveguide; and means for subjecting said waveguide to a tranverse magnetic field; whereby, said transverse magnetic field causes the elongate particles to undergo linear dimension change due to the magnetostrictive effect and to cause linear dimension changes in the optical fiber waveguide so that a laser beam light passing therethrough undergoes phase shifts detectable with interferometry.
Claim 2
Dependent Claim
134 words
An optical fiber waveguide for use in the detection of a magnetic field or magnetic radiation accompanying an electromagnetic signal comprising: an optical fiber waveguide including numerous discrete elongate single-domain magnetized particles; said particles having their longitudinal axes and magnetization vectors disposed generally parallel with the longitudinal axis of the waveguide; a laser with its beam directed into one end of said waveguide; interferometric means for sensing phase shifts in the light of said laser passing through said waveguide; and means for subjecting said waveguide to a tranverse magnetic field; whereby, said transverse magnetic field causes the elongate particles to undergo linear dimension change due to the magnetostrictive effect and to cause linear dimension changes in the optical fiber waveguide so that a laser beam light passing therethrough undergoes phase shifts detectable with interferometry.
Claim 3
Dependent Claim
16 words
The invention according to claim 1 wherein the waveguide includes an optical core and optical cladding.
Claim 4
Dependent Claim
15 words
The invention according to claim 2 wherein the particles are included in the optical core.
Claim 5
Dependent Claim
15 words
The invention according to claim 2 wherein the particles are included in the optical cladding.
Claim 6
Dependent Claim
19 words
The invention according to claim 2 wherein the particles are included in both the optical core and optical cladding.
Claim 7
Dependent Claim
21 words
The invention according to claim 2 further including jacketing secured around the optical cladding with the particles included in the jacketing.
Claim 8
Dependent Claim
128 words
An optical fiber waveguide for use in detecting time-varying magnetic radiation comprising: an optical fiber waveguide of considerable length; said optical fiber waveguide including an array of discrete minute high-aspect ratio magnetized particles all magnetized in the same direction with their axes generally parallel with the axis of waveguide; a laser with it beam directed into one end of said waveguide; interferometric means for sensing phase shifts in the light of said laser passing through said waveguide; and means for subjecting said waveguide to a transverse time-varying magnetic field; whereby said transverse time-varying magnetic radiation causes said particles to undergo linear dimension changes and to cause related linear dimension changes in the optical fiber waveguide for causing a phase shift of laser light passing therethrough detectable by interferometry.
Claim 9
Dependent Claim
128 words
An optical fiber waveguide for use in detecting time-varying magnetic radiation comprising: an optical fiber waveguide of considerable length; said optical fiber waveguide including an array of discrete minute high-aspect ratio magnetized particles all magnetized in the same direction with their axes generally parallel with the axis of waveguide; a laser with it beam directed into one end of said waveguide; interferometric means for sensing phase shifts in the light of said laser passing through said waveguide; and means for subjecting said waveguide to a transverse time-varying magnetic field; whereby said transverse time-varying magnetic radiation causes said particles to undergo linear dimension changes and to cause related linear dimension changes in the optical fiber waveguide for causing a phase shift of laser light passing therethrough detectable by interferometry.
Claim 10
Dependent Claim
17 words
The invention according to claim 7 wherein the waveguide includes an optical core surrounded by optical cladding.
Claim 11
Dependent Claim
14 words
The invention according to claim 8 wherein the particles are included in the core.
Claim 12
Dependent Claim
15 words
The invention according to claim 8 wherein the particles are included in the optical cladding.
Claim 13
Dependent Claim
19 words
The invention according to claim 8 further including jacketing surrounding the optical cladding and which jacketing includes the particles.
Claim 14
Dependent Claim
16 words
The invention according to claim 7, 8, 9, 10 or 11 wherein the particles are nickel.
Claim 15
Dependent Claim
24 words
The invention according to claim 7 wherein the particles comprise up to about 0.1% by volume of the matrix in which they are included.
Claim 16
Dependent Claim
24 words
The invention according to claim 12 wherein the particles comprise up to about 0.1% by volume of the matrix in which they are included.
Claim 17
Dependent Claim
34 words
The invention according to claim 13 wherein the particles have a length along the longitudinal axis of the waveguide of between 150 and 1000 A and a diameter of between 100 and 300 A.
Claim 18
Dependent Claim
34 words
The invention according to claim 14 wherein the particles have a length along the longitudinal axis of the waveguide of between 150 and 1000 A and a diameter of between 100 and 300 A.
Claim 19
Independent Claim
76 words
A method for detecting a transverse magnetic field comprising: directing a beam of laser light into an optical fiber waveguide that includes numerous discrete single-domain magnetized particles, said particles having their longitudinal axes and magnetization vectors disposed generally parallel with the longitudinal axis of said waveguide; subjecting said waveguide to a transverse magnetic field; and detecting by interferometry phase shifts in said light passing through said waveguide caused by magnetostrictive linear dimension changes in said waveguide.
Claim 20
Independent Claim
76 words
A method for detecting a transverse magnetic field comprising: directing a beam of laser light into an optical fiber waveguide that includes numerous discrete single-domain magnetized particles, said particles having their longitudinal axes and magnetization vectors disposed generally parallel with the longitudinal axis of said waveguide; subjecting said waveguide to a transverse magnetic field; and detecting by interferometry phase shifts in said light passing through said waveguide caused by magnetostrictive linear dimension changes in said waveguide.
References Cited (Backward Citations)
US4040890A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-01-31 | 1986-08-02 | 1987-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-31 | 1990-08-02 | 1991-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-31 | 1994-08-02 | 1995-02-01 | $7700.00 | Window Closed / Lapsed |