| 摘要 |
PURPOSE:To increase the degree of freedom of a logic function and to realize application to an optional logic circuit by providing refractive index part dependent on light intensity to a branch connection part for one output optical waveguide of a Y-shaped branching device. CONSTITUTION:The border 7 of a prism part 5 and an optical waveguide 6 forms a nonlinear interface and becomes the border of the prism part 5 which has a refractive index dependent on light intensity and the optical waveguide 6 with a refractive index which does not depend upon light intensity. The refractive index variation state of this nonlinear interface at the time of a light input increase is different from that at the time of a light input decrease, and a threshold value Pth1 is smaller than a threshold value Pth2. Therefore, different histories are obtained at the time of the increase and decrease in light input Pin. Further, as the input Pin approximates zero from the threshold value Pth1, the light output Q' decreases in proportion from a high value PH and the light output Q returns to respective origins while maintaining a low value PL. The bistable element of this constitution has NOT type and positive stable characteristics at the same time, so the logic function can be constituted with the large degree of freedom. |
