Patent ID: 7483610

Claim:
An optical fiber for delivering optical energy including a selected wavelength to or from a work object, comprising: a multimode glass core comprising a diameter of at least 250 microns, said core having an index of refraction; a polymer cladding having a thickness and contactingly surrounding a glass portion of said fiber so as to define an interface between said glass portion and said polymer cladding, said polymer cladding comprising a first index of refraction that is less than said index of refraction; and wherein said fiber comprises a density of less than 0.25 non-conforming regions having a diameter of 25 microns or greater per millimeter of length along said fiber, each of said non-conforming regions being a region visible to the human eye under an optical microscope and having at least a portion thereof within a selected distance of said interface, said distance being less than or equal to said thickness of said polymer cladding, said optical microscope having a total magnification of about 200.