| 摘要 |
PURPOSE:To provide the optical coupling device of a small size capable of coupling two different optical function elements, more particularly the space of the optical function elements integrated with plural devices to each other with low loss. CONSTITUTION:A second core layer 133 formed to a tapered shape along a propagation direction of light is formed on a first core layer 132 formed to the tapered shape along the propagation direction of the light on a semiconductor substrate 131 and the length in the propagation direction of the light of the second core 133 is formed shorter than the length of the first core 132. As a result, the spot size of the light propagating the core layer is changed according to a change in the size of the core layer and the state of confining the light in the core layer is changed by the relative sizes thereof. The loss in the core layers is lowered by setting the relative sizes at prescribed values. As a result, the optical coupling device is constituted to a small size with the low-loss optical coupling characteristic and the higher integration of the devices is realized. |
