Patent ID: 7212716

Claim:
A process for forming an intermediate preform for manufacturing a microstructured optical fibre, comprising: providing a cylindrical mould defining a central axis, said mould comprising a cylindrical container wall, a first base and a removable second base; arranging within said mould a plurality of hole generating elements, thereby defining internal structural elements of the intermediate preform; inserting a fluid optical polymer material or polymer precursor in the mould; consolidating the fluid polymer material or polymer precursor so as to obtain a solid cylindrical polymer body defining the intermediate preform and having embedded the hole generating elements, said hole generating elements being releasably fixed to said first and to said second base and comprising at least one hole generating element removable from said intermediate preform; releasing said hole generating elements from said first and second base; removing the second base from the mould; removing the cylindrical intermediate preform from the mould, together with the therein embedded hole generating elements; and removing said removable hole generating element for forming an elongated hole inside the intermediate preform by applying a load to said removable hole generating element, wherein said removable hole generating element has a diameter greater than 0.1 mm.