IMPROVEMENTS RELATING TO OPTICAL FIBRE COLLIMATORS

摘要

An optical fibre comprising a cladding (4) around a central core (3) has an end portion (5) formed to permit the optical mode size to increase beyond the limits of the core and a microlens (6) is formed on the end face of the fibre. In a described embodiment, the end portion of the fibre is heat treated by a CO2 laser to disperse the core dopant. A 10<2> increase in collimated region is obtainable by virtue of this technique.