| 摘要 |
PURPOSE:To improve the integration degree of the optical circuit and to save the space and improve the functions by arranging plural core layers which have rib parts on one substrate in three dimensions. CONSTITUTION:The core layers 2 and clad layers 3 are laminated alternately on the substrate 1, each core layer 2 projects upward to form the rib part 2a which extend in one direction integrally. Each core layer 2 is upper, middle, and lower stages forms 2, 1, 2 pieces of rib part 2a, respectively, and the core layer 2 and rib part 2a has higher refractive indexes than the clad layer 3 and substrate 1. Therefore, a light beam B is confined to the core layer 2 vertically because of the refractive index difference between the core layer 2 and air or the clad layer 3 and the refractive index difference between the core layer 2 and substrate 1 or clad layer 3, and also confined to right below the rib part 2a horizontally because the effective refractive index of the part right below the rib part 2a is higher than that of its peripheral part. Consequently, the device is reduced in size, improved in the degree of freedom of the shape, and improved in function. |
