Patent ID: 6192715
Filing Date: 2001-02-27
Classification: C03B,Y02P

Abstract:
A furnace for forming an optical fiber, comprising:a furnace body elongated in a vertical direction and defining an inner space into which an optical fiber preform is introduced from a top of the furnace body;a heater for heating the optical fiber preform in the inner space to melt the optical fiber preform;a furnace tube arranged in the furnace body and inside of the heater for separating the heater and the optical fiber preform;an inert gas introduction portion arranged at a lower side wall of the furnace body and introducing inert gas into the inner space of the furnace body;a bottom gas entry preventing means provided at a bottom of the furnace body and having at least one hole through which a drawn optical fiber is passed; anda gas entry prevention controlling means for controlling a differential pressure between a first pressure in the inner space and a second pressure in a chamber formed beneath a first hole formed in the bottom gas entry preventing means to a predetermined value.