OPTICAL FIBER HAVING LOW AND UNIFORM OPTICAL LOSS ALONG THE ENTIRE LENGTH AND METHOD FOR FABRICATING THE SAME

摘要

A method for producing optical fiber preform capable of producing optical fiber having low and uniform optical attenuation loss along its entire length including the top end portion is provided. The method comprises carrying out simultaneously sintering and collapsing steps by inserting the dehydrated hollow soot porous body with predetermined speed in hot zone of the furnace till its top end reaches the hot zone and is left for a predetermined duration thereafter the preform is uplifted for a predetermined length at a predetermined speed to avoid heat loss in the optical preform and re-inserted in the hot zone of sintering furnace at a predetermined speed and left for predetermined duration to result in formation of the preform having collapsed capillary including at its top end.