Satoshi TANAKA, Masahiro MURAKAWA and Yoshihiro OHTSUKA

Department of Applied Physics, Faculty of Engineering, Hokkaido University, Sapporo, 060 Japan

(Received July 1, 1996; Accepted September 12, 1996)

A double fiber-optic Mach-Zehnder interferometer for sensing magnetic fields is devised using two polarization maintaining single-mode fibers. This sensor achieves not only highly sensitive performance but also excellent immunity from temperature disturbance. The sensitivity attains 243 deg/mT (mT=10^-3N/A) for the sensing part of the 5 cm long fiber.

Key words : magnetic-field sensor, double fiber-optic heterodyne polarimetry, immunity from temperature disturbance, polarization maintaining-single mode fiber, magnetostrictive sensor