Fiber structure with improved bend resistance
AssigneeFurukawa Electric North America, Inc.
InventorsJohn M. Fini, Siddharth Ramachandran
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Abstract
A large mode area (LMA) fiber with improved resistance to bend-induced distortions utilizes highly oscillatory modes such that the effective index of the propagating modes remains less than the bent-fiber “equivalent” refractive index over a greater portion of the core. By providing a signal mode with a reduced effective index, the “forbidden” (evanescent) region of the core is reduced, and bend-induced distortion of the propagating mode is largely avoided.
Claims18
A method for propagating an optical signal in a large-mode-area (LMA) optical fiber such that bend-induced distortions are minimized, the method comprising the steps of:
- providing an LMA fiber having a core region with a radius defined as Rcore and a refractive index defined as ncore, said LMA fiber exhibiting a bent-fiber index of Δnbend as said LMA fiber is bent along a predetermined bend radius Rbend;
- and
- coupling an output signal from a highly oscillatory mode signal propagating at a defined wavelength λ within the LMA optical fiber, the highly oscillatory mode signal exhibiting an effective mode area Aeff, the highly oscillatory mode selected to exhibit an effective index neff such that ncore−neff (Δneff) is greater than a predetermined threshold value sufficient to minimize bend-induced distortions.
Dependencies are inferred from the claim text.