PROCESS FOR PRODUCING OPTICAL FIBER PREFORM

摘要

Optical fiber preform with low transmittance loss and with uniformity in overall length of fiber was prepd. by forming a granular glass body(I) with increasing dopant concentration from surroundings to core, heating (I) slowly below the temp. of min. coaggregation of (I) of the core( The that softening of (I) may spread out from core to surrounding, making (I) into vitrified glass body is about 1013 poise at this temp. so that softening of (I) may spread out from core to surrounding, making (I) into vitrified glass body with transparency but without bubbles.