Method and semi-finished product for fabricating multicore fibers

A method for fabricating a multicore fiber, comprising the following method steps:

• (a) providing an elongate base body containing a glass cladding material and having a first end, a second end, a base body longitudinal axis, a base body lateral area, a radial base body cross-section, a base body outer diameter and at least two through-holes which extend through the base body along the base body longitudinal axis;
• (b) inserting a core rod containing a glass core material into the at least two through-holes, thereby forming a component ensemble;
• and,
• (c) drawing the component ensemble to form the multicore fiber or processing the component ensemble further to form a preform from which the multicore fiber is drawn, the component ensemble being held by means of a holder made of glass which is connected to the base body in the region of the first end to form a welding contact surface,
• wherein a holder having an elongate hollow part is used, which holder has a hollow channel with an inner contour which is larger than a circumference of the hole region within which the through-holes lie completely or with at least 90% of their hole diameter, and which has a radial outer dimension which is greater than the base body outer diameter.