Abstract: A system and method for cooling and coating optical fiber includes the capability to control the amount of coolant gas that is fed to and recycled through a heat exchanger for cooling the optical fiber. The capability to control the amount of fed and recycled coolant gas includes measuring at least one parameter selected from the thermal conductivity of the coolant gas, the viscosity of the coolant gas, the diameter of the primary coating on the optical fiber, and the power usage of a coating applicator for applying primary coating on the optical fiber.

Abstract: A method and apparatus for rapidly forming a porous glass preform is provided in which an array of burners is oscillated along a path parallel to the longitudinal axis of the preform. Unlike existing soot deposition techniques, the oscillation amplitude is limited so that each burner deposits soot on only a portion of the preform, e.g., 20% of the preform. By controlling inter-burner variability and the air flow in the burner-array/preform region, preforms having substantially uniform axial properties are obtained notwithstanding the fact that different burners are used to laydown different parts of the preform.

Abstract: Apparatus for rapidly forming a porous glass preform is provided in which an array of burners is oscillated along a path parallel to the longitudinal axis of the preform. The oscillation amplitude is limited so that each burner deposits soot on only a portion of the preform, e.g., 20% of the preform. By controlling inter-burner variability and the air flow in the burner-array/preform region, preforms having substantially uniform diameter and axial properties are obtained.