| 摘要 |
PURPOSE:To efficiently produce a constant-polarization optical fiber preform without any crack, damage, etc., by simple working. CONSTITUTION:A core material and a member for the hole are arranged in a die, a quartz powder is filled in the die, the die is pressed to obtain a porous body, the porous body is refined and vitrified to form a vitreous body, the hole member is extracted from the vitreous body, and a stress-imparting member corresponding to the extracted part and equivalent to size to the resultant hole is inserted into the hole. Besides, the hole member may be drawn before the porous body is refined and vitrified to obtain the vitreous body. |
