METHOD FOR MANUFACTURING OPTICAL FIBER, METHOD FOR MANUFACTURING PREFORM AND APPARATUS FOR MANUFACTURING THE PREFORM

摘要

PROBLEM TO BE SOLVED: To provide a perform which is decreased in variations of outside diameters and an optical fiber. SOLUTION: This method for manufacturing the optical fiber has a setting step of setting heating conditions for heating a glass rod which is a perform of the optical fiber and stretching speed for stretching the same in accordance with the prescribed numerical values changing with the progression of the heating and stretching of the glass rod, a heating and stretching step for forming the perform by heating and stretching the glass in accordance with the set heating conditions and stretching speed rod and a drawing step of forming the optical fiber by further heating the perform and pulling the perform to a fiber form.