Patent ID: 6189343
Filing Date: 2001-02-20
Classification: C03C,Y10S

Abstract:
Optical fiber coating apparatus for providing a coated optical fiber with an axis and a spin with respect to the axis sufficient to provide Polarization Mode Dispersion (PMD) which is not greater than 0.1 ps/Km.sup.1/2, said apparatus comprising:a furnace for softening an optical fiber blank;a tractor for drawing an optical fiber from the softened optical blank and advancing the optical fiber along a path extending from the optical fiber blank, the optical fiber being softened adjacent to the softened optical fiber blank; andspin applying apparatus for applying spin to the softened optical fiber adjacent to the softened optical fiber blank, said spin applying apparatus comprising:at least one rotatable coating applicator extending around the path of the optical fiber and spaced from the softened optical fiber adjacent the softened optical fiber blank in the direction of the tractor for applying a coating material to the optical fiber;a coating material in the applicator, the coating material having a viscosity of at least 1 Pas at the temperature at which the coating material is supplied to the applicator;rotating means coupled to the rotatable coating applicator for rotating the applicator and thereby transmitting torque to the optical fiber through the coating material applied to the optical fiber and applying spin to the softened optical fiber adjacent the softened optical fiber blank, the rotating means being adapted to rotate the rotatable coating applicator at a rotation speed which provides said spin; anda cooling stage disposed intermediate the softened optical fiber and the rotatable coating applicator for cooling fiber in the optical fiber path between the softened optical fiber and the rotatable coating applicator and thereby freezing the spin in the optical fiber which has been produced in the softened optical fiber by rotation of the rotatable coating applicator.