A special spun birefringent fiber optic current sensor

A special spun linear birefringent fiber was designed and achieved for the fiber optic current sensor (FOCS) based on polarization-rotated reflection interferometers. In contrast with conventional sensing fibers used in FOCS the fiber integrates a function of a quarter wave plate. A fiber optic current sensor based on the spun fiber was constructed, and its performance was tested. The sensor output has a good linearity performance in a wide range of current. (10 to 5000Arms). The ratio error is within ±0.1% and the phase error is within ±2 min at a rated AC current of 1000Arms. The sensor could be used for current measuring in the electric power industry and the electrowinning industry.