EP0345759A2
Expired / Lapsed
EP
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A magnetic field measurement apparatus
Assignee: Kansai Electric Power Co Inc
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Filing: 1989-06-07
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Granted: —
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Expires: 2009-06-07
Abstract
Abstract A magnetic field measurement apparatus with high sensitivity and high accuracy in which a Bi-substituted rare-earth iron garnet crystal with a high and no temperature dependent sensitivity constant grown by liquid phase epitaxy is used for a magneto-optic element.
Inventors
- 👤 Osamu Kamada
- 👤 Hisashi Minemoto
- 👤 Kazurou Toda
- 👤 Daisuke Ishiko
- 👤 Satoshi Ishizuka
- 👤 Akihiro Miura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 09:52
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/02; G01R33/032; G01R33/0322
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
165 words
A magnetic field measurement apparatus comprising a magneto-optic transducer that has a polarizer, an analyzer, and a magneto-optic element made of Bi-substituted rare-earth iron garnet crystal which is represented by a general formula Bi x Gd y Y 3-(x+y) Fe₅O₁₂ (1.0 ≦ x ≦ 1.4; 0.1 ≦ y ≦ 0.7) and placed between the polarizer and the analyzer which have polarization directions different from each other; light transmission paths that are provided on both sides of the magneto-optic transducer; a light generating means that supplies light to the light transmitting path; a light detecting means that detects the optical output power generated by the incident light that has passed through the magneto-optic transducer so as to convert the optical output power into electric signals; and an electric circuit that processes the electric signals fed from the light detecting means, wherein the magneto-optic transducer in a magnetic field is placed into the magnetic field to be measured to thereby determine the intensity of the magnetic field.
Claim 2
Dependent Claim
165 words
A magnetic field measurement apparatus comprising a magneto-optic transducer that has a polarizer, an analyzer, and a magneto-optic element made of Bi-substituted rare-earth iron garnet crystal which is represented by a general formula Bi x Gd y Y 3-(x+y) Fe₅O₁₂ (1.0 ≦ x ≦ 1.4; 0.1 ≦ y ≦ 0.7) and placed between the polarizer and the analyzer which have polarization directions different from each other; light transmission paths that are provided on both sides of the magneto-optic transducer; a light generating means that supplies light to the light transmitting path; a light detecting means that detects the optical output power generated by the incident light that has passed through the magneto-optic transducer so as to convert the optical output power into electric signals; and an electric circuit that processes the electric signals fed from the light detecting means, wherein the magneto-optic transducer in a magnetic field is placed into the magnetic field to be measured to thereby determine the intensity of the magnetic field.
Claim 3
Dependent Claim
100 words
A magnetic field measurement apparatus according to claim 1, which comprises a plurality of magneto-optic transducers in the same number as that of the magnetic fields to be measured, a plurality of light detecting means that convert the optical output power into electric signals in the same number as that of the magnetic fields to be measured, and a signal processing circuit that adds and subtracts the electric signals received form each of the detecting means, wherein the magneto-optic transducers are placed into the magnetic fields to be measured to thereby determine the intensity of each of the magnetic fields.
Claim 4
Dependent Claim
30 words
A magnetic field measurement apparatus according to claim 1, wherein said magneto-optic element is made of a crystal that is epitaxially grown on a Ca-Mg-Zr substituted Gd₃Ga₅O₁₂ or Nd₃Ga₅O₁₂ substrate.
Claim 5
Dependent Claim
33 words
A magnetic field measurement apparatus according to claim 1, wherein the spectrum band of said light generating means has a peak at a wavelength in the range of 0.7 µm to 0.9 µm.
References Cited (Backward Citations)
No citation records indexed.
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