Optical fiber for wdm system and manufacturing method thereof

Abstract

An optical fiber having a length of 1 km or more with average transmission loss in a wavelength band of 1383 nm being less than average transmission loss in a wavelength band of 1310 nm, wherein a maximum value of any 1 km section loss in the wavelength band of 1383 nm does not exceed the average transmission loss by 0.03 dB/km or more.

1 : A manufacturing method of an optical fiber, comprising the steps of
 drawing the optical fiber from an optical fiber preform, winding said optical fiber around a bobbin, and then immediately exposing said optical fiber to a deuterium containing atmosphere, wherein   said optical fiber is rewound around another bobbin while applying tensile tension, before said deuterium is completely degassed from said optical fiber.   
   
   
       2 : The manufacturing method of an optical fiber according to  claim 1 , wherein said tensile tension corresponds to 0.5% to 2% in tensile strain of the optical fiber. 
   
   
       3 : The manufacturing method of an optical fiber according to  claim 1 , wherein said optical fiber is cut and divided into predetermined lengths in the longitudinal direction when said optical fiber is rewound.