The optical fiber which is produced by the production method and this method of the optical fiber basic material which uses the MCVD method which includes dehydration and dechlorination process

摘要

The description above clad and being production method of the optical fiber basic material which uses the MCVD method which forms the core on the arrival inside of pipe making use of the flame offer expedient which reciprocating is done it turns according to the axial direction of the arrival tube, while the description above introducing the soot formation gas and the oxygen gas of halogen compound series on the arrival inside of pipe, inducing the soot formation reaction below soot sinterring temperature, the description above stage and the description above which form the soot layer which has the air gap in the inside wall of the arrival tube introducing the dehydration gas into the arrival inside of pipe, while maintaining the aforementioned air gap, the hydroxyl group which exists in the aforementioned soot inside layerStage and the description above which it removes introducing the dechlorination gas into the arrival inside of pipe, while maintaining the aforementioned air gap, stage and the description above which remove the chlorine impurity which exists in the aforementioned soot inside layer heating the arrival tube at temperature above soot sinterring temperature, while changing the constitution of the soot formation gas the stage which makes the aforementioned soot layer sinter and, the process which it includes, according to refractive index profile, production method of the optical fiber basic material which it does over again is disclosed.