| 摘要 |
PURPOSE:To form the optical controlling element having a small in a size, and a very high speed with a low voltage and capable of optically modulating with a high modulation degree by inclining a direction of an electric field applied to a part of transferring a light in a multiple quantum well type structure against an each layers of the structure. CONSTITUTION:The channel optical waveguide 36 leads a light lying in near to an excition resonance absorption wavelength in the i-multiple quantum type structure 6. When a reversed bias voltage is impressed to between the electrode 35a or 35b and the electrode 36, a depletion layer is formed in front parts of P<+>-diffusion ranges 34a, 34b, and the electric field acts in the depletion layer. The channel optical waveguide 36 is positioned near to edges of P<+>-diffusion ranges 34a, 34b, and the slant electric field is applied to the optical waveguide from a direction of the thickness of an epitaxial layer. The effects of the electric fields in the vertical and the horizontal directions are jointly applied to each layers of the multiple quantum well type structure, thereby enabling to modulate at a low voltage. As the strength of the electric field in an edge part of the diffusion front part is usually high in comparison with that of the center of the diffusion front part, the lower voltage can be applied to the titled element. |
