Magnetic-force-induced long-period fiber gratings.

A novel formation method of a long-period fiber grating (LPFG) based on a magnetic-force-induced microbend is proposed and experimentally demonstrated. The LPFG employs a permanent magnet that exerts transversal force to the fiber by attracting a steel coil spring. The transversal force causes periodic microbending to the fiber, and therefore the transmission wave attenuates at the core-to-cladding mode resonance. This device has advantages of ease of fabrication, reconfigurability, and available for any type of fiber.