Optical fiber coating die with reduced wetted length

Abstract

An optical fiber coating apparatus that provides increased gyre stability and reduced gyre strength, thereby providing a more reliable coating application process during fiber drawing includes a cone-only coating die having a conical entrance portion with a tapered wall angled at a half angle α, wherein 2°≤α≤25°, and a cone height L1 less than 2.2 mm, and a cylindrical portion having an inner diameter of d2, wherein 0.1 mm≤d2≤0.5 mm and a cylindrical height of L2, wherein 0.05 mm≤L2≤1.25 mm; a guide die having an optical fiber exit, the guide die disposed adjacent the cone-only coating die such that a wetted length (L5) between the optical fiber exit of the guide die and the entrance of the cone-only coating die is from 1 mm to 5 mm; and a holder for holding the cone-only coating die and the guide die in a fixed relationship defining a coating chamber between the guide die and the cone-only coating die, the coating chamber having an inner radius L6 from the optical fiber axis to an inner wall of the holder that is from 3 mm to 10 mm.

Dependencies are inferred from the claim text.