Observation of a propagation mode of a fiber fuse with a long-period damage track in hole-assisted fiber.

We examined the fiber-fuse propagation characteristics in hole-assisted fibers (HAFs) when the diameter of an inscribed circle linking the air holes was almost the same as the diameter of the melted area caused by the fiber fuse. We observed a new propagation mode for the fiber fuse in HAF with a damage track whose period was approximately 30 times longer than that in conventional single-mode fiber. We also made the first observation of a new threshold power (upper threshold) for the fiber fuse.