Few mode optical fibers for Er doped amplifiers, and amplifiers using such

摘要

According to some embodiments the optical fiber comprises: (i) a glass core doped with greater than 300 ppm of Er₂O₃ and at least 0.5 wt % of Al₂O₃, with a radius R₁ from about 3 μm to about 15 μm, a relative refractive index delta Δ₁ from about between 0.3% to 2% relative to the glass cladding; an effective area of LP01 mode between 20 μm² and 250 μm² at 1550 nm, the glass core radius R₁ and refractive index are selected such that the core is capable of supporting the propagation and transmission of an optical signal with X number of LP modes at a wavelength of 1550 nm, wherein X is an integer greater than 1 and not greater than 20; and (ii) a glass cladding surrounding and in direct contact with the glass core.