A new scheme of the Faraday effect current sensor of a magnetic ring-core type is reported. With this scheme a uniaxial magnetic garnet film is obliquely inserted into a very narrow gap in the ring core and a probe light beam is passed through the garnet film in the transverse direction to the core. It is experimentally demonstrated that this current sensor shows good sensitivity as well as good isolation from surrounding currents, particularly because of the very narrow core gap allowed. This transverse scheme is much simpler and less expensive than the known longitudinal scheme and can offer a practical optical current sensor of a ring-core type.
© 2003 Optical Society of America
(060.2370) Fiber optics and optical communications : Fiber optics sensors
(120.3940) Instrumentation, measurement, and metrology : Metrology
(160.3820) Materials : Magneto-optical materials
(230.2240) Optical devices : Faraday effect
Toshihiko Yoshino, Shin-ichi Torihata, Masayuki Yokota, and Noritaka Tsukada, "Faraday-Effect Optical Current Sensor with a Garnet Film /Ring Core in a Transverse Configuration," Appl. Opt. 42, 1769-1772 (2003)