| 摘要 |
PURPOSE:To form a small-sized optical fiber type coupler with low insertion loss by jointing side surfaces of a couple of semicylindrical optical fibers which have respectively one side surface of a clad part removed almost to a core part. CONSTITUTION:The clad part 12 which has a low refractive index and surrounds the core part 11 having a high refractive index is removed in parallel to a core axis almost to the core part 11. Nearly semicylindrical optical fibers 10 are used. Namely, said optical fibers 10 are jointed mutually with one over the other to length l in the side surfaces where the clad parts are removed. (The overlap part may be coated with a glass capillary.) In this case, said nearly semicylindrical optical fibers 10 are formed easily by polishing one side of a base material consisting of a core 16 and a clad 15 into a surface 17 parallel to the core center axis and then drawing the obtained nearly semicylindrical base material at about 2,100 deg.C. |
