Optical fiber magnetic field sensor

Abstract

Abstract PURPOSE:To reduce a measurement error and to improve reliability by propagating plural light beams with different wavelengths in the same optical path on time-division basis, and processing the difference in the influence of a magnetic field upon those light beams. CONSTITUTION:This system consists of a light source means 11 which has peaks for two wavelengths of lambda1 and lambda2 and sends out light beams with the wavelengths on time-division basis, an optical fiber 12, a polarizer means 13, a magnetooptic effect means 14, a photodetecting means 15, an optical fiber means 16, etc. The light beams of the lambda1 and lambda2 emitted from the light source 11 alternately for tens of mus by a signal from a control means 17 are varied in level and supplied to a photodetecting means 18 as outputs P1 and P2 of electric power. The photodetecting means 18 detects their levels synchronously with the generation timing of those two wavelengths and the results are processed by an analog or digital arithmetic means 19 to find a magnetic field H. Thus, the measurement error is reduced and the reliability is improved.

Inventors

• 👤 Motoo Shimizu
• 👤 清水　基夫

Bibliographic Details