A ferrule used in an optical connector includes a cavity at one end that
contains a malleable disk insert. A cylindrical bore extends through the
insert and supports an optical fiber. The insert is deformed after the
fiber is installed in the bore so that the insert firmly grips the fiber
and the walls of the cavity without adhesives. As a result, relative
movement between the fiber and the ferrule is prevented despite the
expansion and contraction that occur due to temperature variations.