Abstract: Disclosed are optical gain fibers which include an erbium-containing core and a cladding surrounding the core and which have ripple of less than about 25% over about a 40 nm wide window or ripple of less than about 15% over about a 32 nm wide window, or both. In one embodiment, the optical gain fibers are pumpable at 980 nm and at 1480 nm. In another embodiment, the optical gain fibers are fusion sliceable. In yet another embodiment, the core includes oxides erbium; the cladding includes silicon dioxide; and the optical gain fiber has a passive loss of less than about 0.5% of the peak absorption of the erbium absorption band in the vicinity of 1530 nm. The optical gain fibers of the present invention have a wider gain window, improved flatness across the gain window, and/or increased gain as compared to conventional optical gain fibers.

Abstract: Disclosed are optical gain fibers which include an erbium-containing core and a cladding surrounding the core and which have ripple of less than about 25% over about a 40 nm wide window or ripple of less than about 15% over about a 32 nm wide window, or both. In one embodiment, the optical gain fibers are pumpable at 980 nm and at 1480 nm. In another embodiment, the optical gain fibers are fusion sliceable. In yet another embodiment, the core includes oxides erbium; the cladding includes silicon dioxide; and the optical gain fiber has a passive loss of less than about 0.5% of the peak absorption of the erbium absorption band in the vicinity of 1530 nm. The optical gain fibers of the present invention have a wider gain window, improved flatness across the gain window, and/or increased gain as compared to conventional optical gain fibers.

Abstract: The present invention discloses novel methods for fabricating glass articles, particularly optical fiber glass preforms, which may contain alumina, yttrium, lanthanum, erbium, or other rare earth metals as dopants. The glass articles made in accordance with the present invention exhibit radially uniform dopant profiles relative to conventional dopant methods. In addition, the overall concentration of the dopant is increased relative to analogous dopant methods.

Abstract: A method of making a glass article such as an optical waveguide preform is disclosed. The method comprises drawing a rod in at least two steps. In the first step an elongated, consolidated preform having an aperture therethrough is drawn to a reduced diameter preform. The second step involves drawing the reduced diameter preform into a rod, preferably at a lower temperature than the first step. The method substantially reduces the formation of inclusions in the glass article during drawing.

Abstract: A sintered dense glass, alumina-doped optical fiber preform is stretched and is then heated to a temperature of 1490-1495° C. to remove bubbles without causing crystallization. Thereafter, the stretched glass body is either drawn directly into an optical fiber or overclad and then drawn into a fiber.