摘要 |
A method of making an optical fiber employing a wavelength in an infrared region as a wavelength band in use is provided, in which an optical fiber 1 is exposed to an atmosphere containing hydrogen at a concentration of 0.05 vol % but not higher than 4.0 vol % after being drawn and taken up with a bobbin 2 before being put into use, whereas the hydrogen treatment temperature is lower than 50° C., preferably 30° C. or lower, more preferably at room temperature, whereby the increase in loss caused by hydrogen is small even when the optical fiber is used in a wide band, so that the optical fiber can be made efficiently and safely with an optimal hydrogen treatment.
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