| 摘要 |
PURPOSE:To enable fast operation without decreasing the nonlinearity of a refractive index by providing a groove which is <=1/10 as wide as an optical waveguide at least in a semiconductor optical waveguide layer inside or outside the optical waveguide along the optical waveguide. CONSTITUTION:An AlGaAs clad layer 102b which has a striped rib part 106 is formed on a GaAs/AlGaAs MQW (superlattice) waveguide layer 105, and the groove 104 which is <=1/10 as wide as the rib part 106 and reaches the AlGaAs clad layer 102a is formed on both sides of the rib part 106. Then the GaAs/AlGaAs MQW 105 is used as a nonlinear refractive index medium to constitute a nonlinear waveguide element which has two reflecting surfaces 110 as reflecting mirrors. Consequently, while free carriers generated by light incidence 108 are diffused from the optical waveguide part 106 along the optical waveguide layer 105, fast surface rebonding is carried out on the surfaces of the grooves 104 and the operation of the element is speeded up. |
