Back to results
US 4,102,661 AGranted
Caustic ray use of the drawdown zone of an optical fiber preform to control the drawing of the fiber
AssigneeBell Telephone Laboratories, Incorporated
InventorsThomas Dixon Dudderar, Peter Gerald Simpkins
Life of this patent
Estimating the term…
Abstract
A technique for monitoring the drawdown zone of an optical fiber preform is disclosed. The technique involves detecting the caustic rays emanating from the drawdown zone. Analysis of these rays allows one to determine the geometric properties of both the drawdown zone and the resultant optical fiber. In addition, detailed information concerning the index of refraction distribution in the fiber may be obtained. The process is amenable to realtime applications during the drawing of an optical fiber.
Claims12
A method of fabricating an optical fiber comprising:
- heating a portion of an optical fiber preform thereby softening it sufficiently so as to enable drawing;
- drawing the optical fiber preform into an optical fiber while controlling one or more drawing parameters;
- illuminating the optical fiber preform during the drawing process to yield at least one caustic ray emanating from the curved region of the drawdown zone;
- detecting the at least one caustic ray emanating from the curved region of the drawdown zone;
- monitoring variations in the propagation direction of the at least one caustic ray during the drawing process;
- and
- controlling the physical characteristics of the drawdown zone, by controlling at least one drawing parameter in response to the monitoring of the at least one caustic ray.
4 more elements
Dependencies are inferred from the claim text.