Title:
ELECTRIC FIELD SENSOR
Document Type and Number:
WIPO Patent Application WO/2020/153322
Kind Code:
A1
Abstract:
This electric field sensor comprises: a light source; an electro-optic crystal into which light in a prescribed polarization state based on light emitted by the light source is incident, and which receives an electric field generated by an object; a first separation unit that separates light emitted from the electro-optic crystal into a P wave and an S wave; a first wavelength plate that is disposed at a pre-stage of the first separation unit and that changes the phase of light; a first light-receiving unit that receives the P wave light and that converts the received light to a first electrical signal; a second light-receiving unit that receives the S wave light and that converts the received light to a second electrical signal; a differential amplification unit that generates a differential signal between the first electrical signal converted by the first light-receiving unit and the second electrical signal converted by the second light-receiving unit; and a control unit that adjusts a wavelength of the light source so that, in a state in which light is emitted from the light source and an electric field is applied to the electro-optic crystal, an output value of a direct-current component of the differential amplification unit falls in a prescribed value range.
Inventors:
MATSUMOTO YOSHINORI (JP)
SHINAGAWA MITSURU (JP)
KATSUYAMA JUN (JP)
SHINAGAWA MITSURU (JP)
KATSUYAMA JUN (JP)
Application Number:
PCT/JP2020/001833
Publication Date:
July 30, 2020
Filing Date:
January 21, 2020
Export Citation:
Assignee:
YOKOGAWA ELECTRIC CORP (JP)
UNIV HOSEI (JP)
UNIV HOSEI (JP)
International Classes:
G01R29/08; G01R29/12
Foreign References:
JP2005164555A | 2005-06-23 | |||
JPH06230052A | 1994-08-19 | |||
JPH0230046A | 1990-01-31 | |||
JPH0534378A | 1993-02-09 | |||
JPS63144263A | 1988-06-16 | |||
JPH0755891A | 1995-03-03 | |||
JPS59147272A | 1984-08-23 | |||
JP2003204103A | 2003-07-18 | |||
JPS59147273A | 1984-08-23 | |||
US5113131A | 1992-05-12 | |||
JP2019008252A | 2019-01-17 | |||
JP2002122622A | 2002-04-26 | |||
JP2007101384A | 2007-04-19 |
Other References:
See also references of EP 3916401A4
Attorney, Agent or Firm:
TANAI Sumio et al. (JP)
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