Abstract

Optical fibers are commonly manufactured by redrawing a blank or preform by means of a heat source and drawing mechanics. Instabilities in the drawing process, whether periodic or random in nature, manifest themselves in diameter variations frozen into the fiber. Diameter variations in general are undesirable in optical fiber; long term variations cause difficulties for subsequent splicing and cabling processes, while short term variations may influence the transmission characteristic adversely. An optical technique was developed to continuously measure the outer diameter as well as core-to-cladding ratio for step index fibers, with an update rate of 2000 per second.

© 1975 Optical Society of America