OPTICAL FIBER HAVING REDUCED POLARISATION MODE DISPERSION

摘要

A method of manufacturing an optical fiber comprising a core portion with a dopant and a surrounding optical cladding portion, comprising the steps of drawing a fiber (7) from a molten extremity (3) of a silica preform (1) and moving the fiber (7) along means (9) for coating it with a protective sheath, whereby, prior to the coating step, the moving fiber (7) is irradiated with irregularly modulated actinic radiation (15), thereby causing corresponding irregular variations in the refractive index of its core portion as a function of longitudinal position. The resulting fiber demonstrates a significantly reduced polarisation mode dispersion.