Patent ID: 7050686
Filing Date: 2006-05-23
Classification: G02B

Abstract:
1. An optical fiber, comprising: a core comprising a concentration of at least one rare earth for providing light having a first wavelength responsive to said fiber being pumped by light having a second wavelength that is different than said first wavelength; an inner region disposed about said core, said inner region comprising a silica glass; a cladding disposed about said inner region, said cladding comprising silica; a second cladding disposed about said cladding; wherein the index of refraction of the second cladding is less than that of the cladding, the index of refraction of the cladding is less than that of the inner region, and the index of refraction of the inner region is less than that of the core; and wherein said core comprises a V-number at said first wavelength of greater than 2.405 and wherein said core comprises a numerical aperture (NA) of less than 0.12.