Optical fiber manufacture method, preform manufacture method, and preform manufacture apparatus

A method for manufacturing an optical fiber comprising:

• heating and elongating a glass rod, which is a parent material of an optical fiber, to generate a preform,
• drawing said preform with further heating to a filament-like form to generate an optical fiber;
• and
• said heating and elongating has:
• pre-heating said glass rod until prescribed region of said glass rod softens;
• and
• end drawing said prescribed region for reducing a diameter of said prescribed region and for making an end of said glass rod by further heating and elongating said prescribed region.

An apparatus for manufacturing a preform, which is a parent material of an optical fiber, comprising:

• a heating source which heats a glass rod, which is a parent material of said preform;
• an elongating unit which elongates said glass rod;
• a measurement device for measuring a numerical value which changes with a progress of elongation of said glass rod;
• and
• a control unit which controls a heating condition of said heating source and a elongating speed of said elongating unit based on said numerical value measured by said measurement device.