Title:
【発明の名称】光ファイバ応用センサ
Document Type and Number:
Japanese Patent JP3175935
Kind Code:
B2
Abstract:
A fiberoptic sensor is provided with a detector that is inserted in a light transmission line constituted of an optical fiber cable. The detector includes an optical modulator which modulates polarization utilizing the fact that the magnitude of double refraction varies with the physical quantity to be detected. The detector further includes an optical element connected in series with the optical modulator and adapted to convert the polarization into a change of light intensity. Light beams of different wavelengths lambda 1 and lambda 2 emitted from the two sources of light are commonly incident on one end of the light transmission line. Intensities P1, P2 of the light beams of wavelengths lambda 1, lambda 2 emitted from the other ends of the light transmission line are detected. The light intensities P1, P2 vary depending upon the change in the light intensities of sources of light, the change in losses through the optical fiber cable and optical connectors, and the physical quantity to be dedetected. In order to detect data free from unwanted change in the optical intensities of sources of light and change in the losses through the optical fiber and optical connectors, one embodiment is provided with means for controlling either one of the two sources of light to equalize the light intensities P1 and P2, and means for detecting light intensities P01 and P02 of the two sources of light to calculate (P01 - P02)/(P01 + P02).
Inventors:
Kyoichi Tatsuno
Toshiya Umeda
Toshiya Umeda
Application Number:
JP23687188A
Publication Date:
June 11, 2001
Filing Date:
September 21, 1988
Export Citation:
Assignee:
Toshiba Corporation
International Classes:
G01D5/26; G01D5/34; G01L1/24; G01R15/24; (IPC1-7): G01R15/24; G01D5/26
Domestic Patent References:
| JP61118633A | ||||
| JP61234364A | ||||
| JP61221652A | ||||
| JP60214220A | ||||
| JP59145971A | ||||
| JP57171271A |
Attorney, Agent or Firm:
Takehiko Suzue (2 outside)