Method of observing the core region of optical fibers and preforms
AssigneeBell Telephone Laboratories, Incorporated
InventorHerman M. Presby
Life of this patent
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Abstract
A method of observing the core region of optical fibers and fiber preforms is disclosed comprising the step of inducing fluorescence in at least one of the index-modifying dopants present in the core being observed by illuminating said fiber/preform with radiation at the peak absorption wavelength for said dopant, and observing the region between the fluorescing edges of said fiber/preform. The core diameter can be determined by measuring the distance between said edges. This technique can be utilized to control the fiber pulling rate during fabrication.
Claims5
A method of outlining the core region of optical fibers and fiber preforms comprising the step of:
- inducing fluorescence in at least one of the index-modifying dopants present in the core (11) by illuminating said fiber/preform with radiation at the peak absorption wavelength from said dopant.
The method of pulling a fiber from a fiber preform including the steps of:
- pulling said fiber from said preform at an adjustable rate;
- illuminating said fiber as it is drawn with radiation at the peak absorption wavelength for at least one of the index-modifying dopant present in the fiber core;
- determining the diameter of the core region of said fiber by measuring the distance between the fluorescing edges of said fiber;
- comparing the measured diameter with a predetermined desired core diameter;
- and
- adjusting the fiber pulling rate in response to said comparison.
Dependencies are inferred from the claim text.