A method and an arrangement for supplying optical fibers

A method and an arrangement in which optical fiber lengths (13) are mechanically unwound from a fiber drum (23) in the axial direction in the process of preparing the fiber lengths (13) for different applications e.g. connection to microelectronic devices. The fiber is unwound by initial lifting the fiber in the radial direction of the drum and subsequent guiding of the fiber axially along the drum by an unwinding means (27) and is discharged at the center of one side of the drum. The method and arrangement include monitoring steps for measuring light influenced by a prepared length at the second not unwound fiber end on the drum by means of a light processing apparatus (42) and comparing the actual value of an optical parameter of the influenced light to a preset value.