摘要 |
PURPOSE:To make it possible to optically couple optical fibers with a thin-film light transmission line with efficiency by employing the constitution in which the core shape of the end part of optical fibers optically coupled with the rectangular flank of the thin-film light transmission line is gradually changed from a circle to an oval. CONSTITUTION:At both the sides of one end of optical fiber 3 to be optically coupled, reinforcing members of fixed length, i.e. glass guides 4 and 5 are bonded sandwiching. Glass guides 4 and 5 use a glass material that has softening temperature and a thermal expansion coefficient nearly equal to those of core glass 1 or clad glass 2 of optical fiber 3. Next, optical fiber 3 and bonded glass guides 4 and 5 are elongated being integrally heated in a heating method such as arc discharge so that the sgape of the part will nearly be circular. Then, fabricated fiber 6 is cut at its thinned part, whose cut section is flank-processed by polishing, chemical etching, etc. Thus the core shape of the end of optical fiber 6 is determined and core section 1' shown by fiber flank 7, i.e. the flank of optical fiber 6 in an oval shape can be obtained. |