Patent ID: 6208775
Filing Date: 2001-03-27
Classification: G02B,H01S

Abstract:
A current sensor comprisinga) a source of linearly polarized light;b) a transformer of polarized light for transforming the linearly polarized light to circularly polarized light, said transformer including a birefringent fiber which is twisted through an angle into a corkscrew shape at an appropriate distance from an end of the fiber, the angle and distance so chosen that linearly polarized light entering an end of the fiber farthest from the corkscrew shape exits the fiber circularly polarized;c) a coil of optical fiber having multiple turns;d) a directional coupler for optically coupling the circularly polarized light from the transformer of polarized light to the coil to create counter-propagating light beams within the coil; ande) an optical detector for receiving said counter-propagated light beams for producing an output signal indicative of a magnetic field produced by an electric current.