INDEX MATCHED GRATING INSCRIPTION

摘要

The disclosed embodiments provide systems and methods for mitigating lensing and scattering as an optical fiber is being inscribed with a grating. The disclosed systems and methods mitigate the lensing phenomenon by surrounding an optical fiber with an index-matching material that is held in a vessel with an integrated interferometer (e.g., phase mask, etc.). The index-matching material has a refractive index that is sufficient to reduce intensity variations of the actinic radiation within the optical fiber. Some embodiments of the system include different vessels for holding the index-matching material, with the vessel having an interferometer integrated into the vessel. These vessels permit the optical fiber to be surrounded by the index-matching material while the gratings are written to the optical fiber.

主权项

1. An optical fiber, comprising:
an outer diameter (Rfiber); a fiber index of refraction (nfiber); an offset core following a helical trajectory along an axial direction along the optical fiber, the offset core being offset from a center of the optical fiber by Roffset; gratings written on the offset core, the gratings being written with the optical fiber being surrounded by an index-matching material, the index-matching material having an index of refraction (nsurround), the gratings having a maximum grating strength, the gratings having a minimum gratings strength, a ratio of the minimum grating strength to the maximum grating strength being:1-ρ(η-1)1+ρ(η-1), where η=nfiber/nsurround, ρ<1/η, and ρ=Roffset/Rfiber.