Abstract:
A few mode optical fiber comprising: a Ge-free core having an effective area Aeff of LP01 mode wherein 120 μm2 ΔrMIN; and |Δ0−ΔOuter-Clad|>0.05%, the relative refractive index profile of the optical fiber is selected to provide attenuation of 1600 nm.
Abstract:
In embodiments, a mode selective optical fiber coupler may include a first propagation waveguide and a second propagation waveguide joined along a coupling length L. The first propagation waveguide and the second propagation waveguide may be tapered from an input face and an output face of the coupler to a midpoint of the coupler. An LP01 mode of an optical signal with a wavelength of 800-950 nm coupled into the first propagation waveguide propagates through the first propagation waveguide and is emitted from the first propagation waveguide. An LP01 loss of the coupler at the output face is less than 1.0 dB. An LP11 mode of the optical signal coupled into the first propagation waveguide is cross-coupled to the second propagation waveguide and is emitted from the second propagation waveguide. An LP11 loss of the coupler at the output face is less than 1.5 dB.
Abstract:
According to some embodiments a few moded optical fiber includes a glass core structured to provide light amplification at an amplification wavelength and a cladding surrounding the core. According to some embodiments the core of the few moded optical fiber includes a portion that has an average concentration of rare earth dopant which is lower by at least 30%, and preferably by at least 50%, than the average concentration of the rare earth dopant at another portion of the core that is situated further from the core center.
Abstract:
According to some embodiments a few moded optical fiber includes a glass core structured to provide light amplification at an amplification wavelength and a cladding surrounding the core. According to some embodiments the core of the few moded optical fiber includes a portion that has an average concentration of rare earth dopant which is lower by at least 30%, and preferably by at least 50%, than the average concentration of the rare earth dopant at another portion of the core that is situated further from the core center.