EP0044572A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Apparatus for measuring the intensity of magnetic fields by an optical fiber
Assignee: Hitachi Ltd
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Filing: 1981-07-23
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Granted: —
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Expires: 2001-07-23
Abstract
Abstract An apparatus for measuring the intensity of a magnetic field includes a measuring detector composed of an optical fiber coil (4). The radius R of the coil (4) is defined by the following Equation: wherein m denotes an integer and L denotes the length at which the birefringency of the optical fiber becomes 2 n.
Inventors
- 👤 Hiroyoshi Matsumura
- 👤 Toshio Katsuyama
- 👤 Tsuneo Suganuma
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-22 18:44
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/032; G01R33/0322
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
142 words
An apparatus for measuring the intensity of a magnetic field, comprising: means (1, 2) for generating polarized light; a detector (4) for rotating the polarization plane of the light due to a magnetic field; a first transmission path (3-1) for transmitting the polarized light from the generating means (1) to said detector (4); light receiving means (5, 6) for detecting the output light of said detector (4); and a second transmission path (3-2) for transmitting the output of said detector (4) to said light receiving means (5, 6), characterized in that said detector (4) is formed of an optical fiber wound into a coil shape, and in that the length of the optical fiber. wound into the coil shape is a multiple of an odd number of the length L, at which the birefringence intrinsic to said optical fiber is 2 π.
Claim 2
Independent Claim
142 words
An apparatus for measuring the intensity of a magnetic field, comprising: means (1, 2) for generating polarized light; a detector (4) for rotating the polarization plane of the light due to a magnetic field; a first transmission path (3-1) for transmitting the polarized light from the generating means (1) to said detector (4); light receiving means (5, 6) for detecting the output light of said detector (4); and a second transmission path (3-2) for transmitting the output of said detector (4) to said light receiving means (5, 6), characterized in that said detector (4) is formed of an optical fiber wound into a coil shape, and in that the length of the optical fiber. wound into the coil shape is a multiple of an odd number of the length L, at which the birefringence intrinsic to said optical fiber is 2 π.
Claim 3
Dependent Claim
28 words
The apparatus of claim 1, characterized in that the coil shape is a circle having a radius R expressed by the following Equation: wherein m is an integer.
Claim 4
Dependent Claim
34 words
The apparatus of claim 1 or 2, characterized in that the optical fibers of said first and second transmission paths (3-1, 3-2) and of said detector (4) are constructed of an identical optical fiber.
Claim 5
Independent Claim
60 words
The apparatus of any of the claims 1 to 3, characterized in that said optical fiber includes a core (10) of silicate glass doped with phosphorous pentoxide (P 2 0 5 ) and germanium oxide (Ge0 2 ), a cladding (11) of silicate glass doped with phosphorous pentoxide (P 2 0 5 ), and a jacket (12) of silicate glass.
Claim 6
Independent Claim
69 words
The apparatus of any one of claims 1 to 4, characterized in that means for generating the polarized light is constructed of a light emitting element (11) and a polarizing element (12), and that said light receiving means is constructed of a light detecting element (5) and a light receiving device (6) which are at a predetermined angle with respect to the polarization plane of said polarizing element (2).
References Cited (Backward Citations)
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