A of fabricating a partially flexible optical fiber bundle includes forming plural helical fiber ribbons, each helical ribbon being formed by winding a fiber about a mandrel and adjacently fusing a first selected set of fiber portions within each ribbon to define and ends region. The ends regions of multiple fiber helixes are stacked and bonded to form a fiber bundle with and ends section. The ends section is cut through to yield opposed input and output ends of the fiber bundle. Intermediate rigid sections are formed along the length of the bundle by various alternative methods of adjacently bonding selected portions of the constituent ribbon and bundle fibers.