Method of Preparation of a Multicore Fiber Preform

A method of manufacturing a multicore fiber preform, the method comprising:

• (a) providing a first cylinder extending longitudinally between opposing first and second ends;
• (b) providing a second cylinder extending longitudinally between opposing first and second ends;
• (c) forming a plurality of first holes in the first cylinder that each have a generally constant first inner diameter and extend longitudinally through the first cylinder and forming a plurality of second holes in the second cylinder that each have a generally constant second inner diameter and extend longitudinally through the second cylinder;
• (d) forming at least one first recess in the first end of the first cylinder such that the plurality of first holes each terminate at the at least one first recess at a location axially spaced apart from the first end of the first cylinder;
• (e) facing the first end of the first cylinder to the second end of the second cylinder and axially aligning each of the plurality of first holes with respective ones of the plurality of second holes;
• (f) welding the first end of the first cylinder to the second end of the second cylinder;
• and
• (g) for each first hole and its respective axially aligned second hole, inserting a respective core rod assembly.