摘要 |
PROBLEM TO BE SOLVED: To provide a non-linear grating coupler capable of actively selecting the position of discharged light diffracted to the outside only changing the power of incident light. SOLUTION: The coupler has tapered non-linear thin films 2, 12 formed on respective substrates 1, 11 and having tertiary non-linearity, linear optical waveguides 3, 13 formed on the upper part of the thin films 2, 12 and having refractive index larger than the linear refractive index of the thin films 2, 12 and grating structure components 4 formed on the upper part of the waveguides 3, 13. Since the critical power of the thin films 2, 12 depends upon the thickness of the thin films 2, 12, a propagation distance up to diffraction can be changed by the power of light. |