| 摘要 |
PROBLEM TO BE SOLVED: To provide an MMI type optical branching device that has a structure facilitating optical coupling with an optical fiber and that can be easily manufactured at low cost. SOLUTION: This optical branching device is connected to an incident side optical fiber 61 and a first and second emitting side optical fibers 62, 63. The device is equipped with first and second covers 69, 70 consisting of a clad material for confining light, first and second guides 71, 72 for positioning optical fibers, and a branching part 73 for branching the incident light and emitting it. In addition, the branching part 73 includes: a slab 66 which consists of a core material having a higher refractive index than a clad material and which branches a light beam through multimode interference; first and second waveguide cores 67, 68 which consist of a core material and which emit the light beam from the slab 66 to the first and second emitting side optical fibers 62, 63; and a substrate 74 which consists of a clad material. |
