| 摘要 |
<p>Method of observing the core region (11) of-optical fibers (10) and fiber preforms 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. </p> |
