Abstract: A method for manufacturing a fiber package for use in an optical communication device, is comprised the steps of: preparing a ribbon-type fiber stack having a pair of sheared sides, the ribbon-type fiber stack being provided with a plurality of fragmental optical fibers, each of fragmental optical fibers including a core surrounded by a cladding; partially peeling the claddings from the fragmental optical fibers to expose the cores; forming gratings into the exposed cores; and installing a pair of side connections on the pair of sheared sides in the ribbon-type fiber stack, thereby forming a fiber package. In the invention method, the ribbon-type fiber stack and a pair of side connections are utilized, which can remove a need for the step of packing the optical fiber(s), simplifying the formation of the fiber stack.

Abstract: A dispersion compensation device and an optical transmission system are capable of simultaneously compensating a dispersion value and dispersion slope in a single-mode optical fiber in a high-speed long-distance optical transmission system and a wavelength division optical transmission system. The dispersion compensation device includes N number of component optical fibers arranged in a serial fashion, N being a positive integer more than one, wherein each of the component optical fiber has a different dispersion value per a unit length, a dispersion slope per a unit length, and a different length.

Abstract: A method for manufacturing a fiber package for use in an optical communication device, is comprised the steps of: preparing a ribbon-type fiber stack having a pair of sheared sides, the ribbon-type fiber stack being provided with a plurality of fragmental optical fibers, each of fragmental optical fibers including a core surrounded by a cladding; partially peeling the claddings from the fragmental optical fibers to expose the cores; forming gratings into the exposed cores; and installing a pair of side connections on the pair of sheared sides in the ribbon-type fiber stack, thereby forming a fiber package. In the invention method, the ribbon-type fiber stack and a pair of side connections are utilized, which can remove a need for the step of packing the optical fiber(s), simplifying the formation of the fiber stack.

Abstract: A rare earth-doped optical fiber comprises a cladding, a center core doped with a rare earth element, the center core having a refractive index higher than that of the cladding, and a ring-shaped core surrounding the center core without contact and having a refractive index higher than that of the cladding and lower than that of the center core.