Optical fiber component for spot size transition and method of making the same

摘要

A large-diameter core optical fiber and a small-diameter core high optical fiber are fusion-spliced, and the spliced portion is heated to expand the core diameter of a core of the high optical fiber and form a spot size transition portion, whereby spot sizes of the optical fibers are matched and relative refractive index differences thereof are made substantially identical. Subsequently, the optical fiber is cut at an arbitrary position and the spliced portion and the spot size transition portion are placed inside a ferule with the large diameter core optical fiber arranged on a light incident and outgoing end face side of the ferrule to form an optical fiber component. The core diameter is expanded while monitoring transition loss of the splined portion to obtain an optical fiber component having an optimal spot size transition portion without an advanced technique and without increase in transition loss.