Miniature microstructured fiber coil with high magneto-optical sensitivity

Magneto-optic Faraday Effect in a miniature coil wound from a microstructured spun-type optical fiber is investigated theoretically and experimentally for the first time. It is shown that such a microstructured fiber allows one to efficiently accumulate the Faraday phase shift in a magnetic field even when the fiber is wound into a coil of very small diameter. For example, a fiber coil of diameter 5 mm with 100 turns has a magneto-optic sensitivity of about 70% of its “ideal” value and agrees well with theoretical data.