| 摘要 |
PURPOSE:To enable to control an active layer in a parallel direction mode by determining the refractive indexes and the thickness of the layers so that zero order mode is cut off in the part except the groove on the surface of a substrate. CONSTITUTION:A stripe groove 10 is formed on a P type GaAs substrate 6, an N type GaAlAs clad layer (refractive index: n1)1, N type GaAlAs layer (refractive index: n2), an N type GaAlAs active layer (refractive index: n3) 3, a P type GaAlAs clad layer (refractive index: n4) 4, and a P type GaAs cap layer 5 are sequentially laminated thereon. Then, after an oxidized film 7 is arragned on the layer 5, electrodes 8, 9 are formed. The refractive indexes of the layers are set to the relationship of n3>n2>n1>n4, and the refractive indexes and the thicknesses of the layers are determined so that zero order mode is cut off at the part except the groove 10. Thus, zero order mode is cut off except the groove 10, and the light is hot guided. Since the thickness of the layer 1 becomes thick in the groove 10, the light can be stably guided as 4-layer waveguide. |
