OPTICAL FIBER COUPLER AND PROCESS AND DEVICE FOR PRODUCING THE SAME

摘要

A conventional optical fiber coupler requires a preprocessing process or different optical fibers having strictly uniform characteristics. The inventive optical fiber coupler is a 1x2 wide band optical fiber coupler for branching or coupling propagating lights between an optical fiber (1a) and an optical fiber (1b). Both optical fibers (1a, 1b) are identical single-mode optical fibers available on the market as a standard type. An optical coupling part (21) of the optical fiber coupler is formed by fusing and elongating the optical fibers (1a, 1b) with a part of the optical fiber (1b) kept wound around the optical fiber (1a). Winding amount of the optical fiber (1b) with respect to the optical fiber (1a) is adjusted such that the difference in length between both optical fibers (1a, 1b) at the optical coupling part (21) is equal to the minimum possible length required for substantially equalizing the degrees of coupling of propagating lights at the optical fibers (1a, 1b).