RARE EARTH DOPED OPTICAL FIBRES AND LARGE EFFECTIVE AREA OPTICAL FIBERS FOR FIBER LASERS AND AMPLIFIERS

摘要

The present invention relates to a large-core optical fiber and a large-core optical fiber system, wherein the optical fiber comprises of a core having a core raidius ρ and a core index of refraction ncore; a first cladding disposed about said core, said first cladding having an outer radius ρ1 and an index of refraction ncl, said core and said first cladding having a difference in index of refraction Δn = ncore - ncl, and a numerical aperture (NA) less than about 0.05, said NA determined by ncore and ncl; and a second cladding disposed about said first cladding, said first cladding and said second cladding having a difference in index of refraction Δn1, wherein the first cladding radius ρ1 is greater than about 1.1 ρ and less than about 2 ρ and the refractive index difference between said first cladding and said second cladding, Δn1, is greater than about 1.5 Δn and less than about 50 Δn. The optical fiber system for providing optical amplification consists of the large-core optical fiber, wherein said core of said large-core fiber is doped with one or more types of rare earth ions, said large-core optical fiber comprising of a combined waveguide formed by said core and said first cladding layer; an optical pump optically coupled to said large-core optical fiber; and an optical source optically coupled to an input of said large-core optical fiber.