Splicing different optical fiber types

摘要

When splicing optical fibers of different kinds to each other by means of arc welding, a matching of the mode field diameters of the fibers is desired. This is accomplished by prolonging (period 55) the heating after making the splice (period 53). During the prolonged heating the hot-fiber indices of the two fiber ends are continuously determined. Either one of these indices or some suitable quantity derived therefrom is all the time compared to a threshold value and when it is reached the heating is stopped. The threshold value has been determined in a preceding stage using test fiber pieces of the same kind in a splicing operation with prolonged heating. Then, in such a threshold level determining stage in addition to the hot-fiber indices, the transmission of light is constantly measured during the heating and when it has its maximum value the corresponding hot-fiber indices are stored and used for deriving the threshold value. This method of matching mode field diameters is simple and takes a short time.