| 摘要 |
PURPOSE:To decrease transmission loss by using an optical waveguide of multimodes to transmit single mode. CONSTITUTION:A GaAlAs layer 2 having a low refractive index as a clad layer is inserted between an n<->-GaAs layer 3 and an n<+>-GaAs substrate 1 to increase the restraint of light in the thickness direction and to confine the light wave into the n<->-GaAs layer which is a low absorption loss layer. The restraint of the light wave into the thickness direction increases further when the film thickness of the n<->-GaAs layer increases gradually. The absorption loss from the substrate as well as the scattering and diffraction loss by the surface roughness and bending of the optical waveguide are thereby decreased. |
