Abstract: A method for fusion-forming an optical signal attenuator using a piece of optical fibre, comprising essentially the following steps:a) fusing the piece of optical fibre;b) manipulating the piece of optical fibre during fusion;c) inserting the piece of optical fibre into a mechanical adaptor for connection to two standard connectors butt-coupled respectively to the ends of two optical fibres, wherein the manipulation of the piece of optical fibre during fusion is effected by subjecting the piece of optical fibre to both axial misalignment and angular misalignment.