THERMALLY ANNEALED GRATINGS IN COATED FIBER AND RELATED SYSTEMS AND METHODS

Described herein are systems, methods, and articles of manufacture for a coated fiber modified by actinic radiation to increase back-scattering, which experiences very little back-scattering decay at a temperature and time of exposure that is sufficient to noticeably degrade the coating and/or noticeably degrade the optical fiber due to outgassing of hydrogen from the coating. In one embodiment, an optical fiber comprises a fiber length, a coating having a treated coating weight, wherein the treated coating weight is at least 25% less of an original coating weight prior to an annealing treatment, and an optical back-scatter along the fiber length greater than a Rayleigh back-scattering over the fiber length, wherein the optical back-scatter does not decrease along the fiber length by more than 3 dB after exposure to annealing treatment. A further embodiment relates to a method comprising receiving an optical fiber at an inlet of at least one heat source, the optical fiber including a coating having an original coating weight and an optical back-scatter along a fiber length and applying an annealing treatment to the optical fiber by the least one heat source at a predetermined temperature Ta during a predetermined time ta, wherein the original coating weight is reduced by at least 25% to a treated coating weight during the annealing treatment, wherein the optical back-scatter does not decrease along the fiber length by more than 3 dB after the annealing treatment.