Abstract: An aluminum alloy wire manufacturing method comprises (A) a step for melting an aluminum alloy containing 0.40-0.55 mass % of Mg and 0.45-0.65 mass % of Si, the balance being obtained from Al and unavoidable impurities, (B) a step for casting molten metal of the aluminum alloy and rolling to form a rough-drawn wire rod, (C) a step for solutionizing the rough-drawn wire rod, (D) a step for drawing the rough-drawn wire rod after solutionizing to form a drawn wire rod with a wire diameter of 0.5 mm or less, and (E) a step for heat treatment so that internal strain is removed with substantially no deposition of Mg2Si.

Abstract: An aluminum alloy wire manufacturing method comprises (A) a step for melting an aluminum alloy containing 0.40-0.55 mass % of Mg and 0.45-0.65 mass % of Si, the balance being obtained from Al and unavoidable impurities, (B) a step for casting molten metal of the aluminum alloy and rolling to form a rough-drawn wire rod, (C) a step for solutionizing the rough-drawn wire rod, (D) a step for drawing the rough-drawn wire rod after solutionizing to form a drawn wire rod with a wire diameter of 0.5 mm or less, and (E) a step for heat treatment so that internal strain is removed with substantially no deposition of Mg2Si.

Abstract: A method of manufacturing an incorporated ferrule (13) with attenuation optical fiber comprising the step of cutting off a long capillary with an attenuation optical fiber (6) into a plurality of short capillaries (12) with attenuation optical fiber of specified lengths, and polishing the end faces (12a) and (12b) of the short capillaries (12) with attenuation optical fiber.

Abstract: 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.

Abstract: A large-diameter core optical fiber and a small-diameter core high &Dgr; optical fiber are fusion-spliced, and the vicinity of a spliced portion is heated to expand a core diameter of a core of the high &Dgr; optical fiber and form a spot size transition portion, whereby spot sizes of the optical fiber and the high &Dgr; optical fiber are matched and relative refractive index differences thereof are made substantially identical. Subsequently, an arbitrary position of the optical fiber is cut such that the spliced portion and the spot size transition portion are placed inside a ferule, and the optical fiber is arranged on a light incident and outgoing end face side of the ferrule to form an optical fiber component. It is advisable to expand the core diameter of the core while monitoring a transition loss of the spliced portion.