| 摘要 |
PROBLEM TO BE SOLVED: To design a structure having coupling efficiency of an optical bistable characteristic by constituting with a linear optical waveguide having a refractive index larger than the refractive index of a nonlinear optical waveguide and containing an optical waveguide grating patterned on the linear optical waveguide when power of incident light is smaller than a prescribed critical value. SOLUTION: When the incident light having the power smaller than the critical power is made incident on the area of the linear optical waveguide 13 of a nonlinear optical waveguide grating structure, since the linear refractive index of the nonlinear optical waveguide 12 is smaller than the refractive index of the linear optical waveguide 13, the incident light is restricted in the inside of the linear optical waveguide 13. Waveguided light restricted in the inside of the linear optical waveguide 13 is diffracted by a grating structure 14 to be discharged from a substrate side to the outside. On the other hand, when the power of the incident light is larger than the critical power, the refractive index of the nonlinear optical waveguide 12 becomes larger than the refractive index of the linear optical waveguide 13 by the nonlinearity of the nonlinear optical waveguide 12. Thus, the dower of the incident light is transmitted to the area of the nonlinear optical waveguide 12, and advances along a path of a nonlinear thin film. |
