Sensing fiber, coil of sensing fiber, and all-fiber current sensor

摘要

Embodiments of the present invention provide a sensing fiber, which includes a polarization-maintaining (PM) fiber being spun around a core thereof to have a first, a second, and a third sections, wherein the first section has an increasing rate of spin from a predetermined slow rate to a predetermined fast rate; the second section is spun at the predetermined fast rate; and the third section has a decreasing rate of spin from the predetermined fast rate to the predetermined slow rate. The first and third sections have a substantially same length and changes in rate of spin are substantially symmetric to each other. Embodiments of the present invention also provide a fiber coil made by the sensing fiber, with the first section and the third section being substantially overlapped along the coil, and provide an all-fiber current sensor employing the fiber coil.