| 摘要 |
PURPOSE:To permit high-speed modulation without having the possibility of light crosstalks and to permit easy integration on the same substrate as the substrate of a light source by executing modulation of light by the light absorption by surface plasmon and polariton. CONSTITUTION:A light guide system successively formed with a distribution feedback type semiconductor laser (DFB laser) 8, a light guide 9 and a quantum well guide 4 for optical modulation and a light guide system connected to a quantum well guide 4 for optical modulation and a light guide 9' which are crossed at a prescribed angle 2alpha are formed on the semiconductor substrate 10. The light guides 9 and 9' constitute a V-shaped light guide 7. A LiF2 film is used as a medium 1, air as a medium 2, and a thin silver film as a thin silver film 3 having a negative dielectric constant. The media 1, 2 have the positive dielectric constants of smaller than the refractive indices of the semiconductor substrate. A modulation signal is impressed from a modulation signal source via electrodes 5, 5' to this modulator to change the refractive index in the region of the quantum structure and the incident wave is totally reflected by a light reflection surface 6, by which the modulation of the light is executed. Since the modulation is executed by the absorption of the light by the surface electromagnetic wave mode, there is no possibility of the crosstalks of the light and the high-speed modulation is possible; in addition, the easy integration on the same substrate as the substrate of the light source is possible. |
