| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical branching device which is easily produced with a low cost and is capable of multi-branching. SOLUTION: The optical branching device is composed of one incidence-side optical fiber 16, nine reception-side optical fibers 17 to 25, and a tapered waveguide 26. In each of these optical fibers 16 to 25, the core diameter is 14, and the refractive index of the core is 1.492, and that of the clad is 1.417, and NA=0.47. The tapered waveguide 26 is produced by injection molding and is a truncated pyramid (tapered) having a square section, and the core material is a polymethyl methacrylate whose refractive index is 1.491, and the clad material is air. The refractive index of the core is higher than that of the clad. The sectional area on the light incidence side is larger than that on the light emission side. Thus, incident light is branched into 9 emitted light by the tapering waveguide 26. |
