| 摘要 |
An optically controlled integrated circuit device for microwave signalling/switching is configured of a microstrip structure formed on a thin layer of active semiconductor material, such as doped GaAs or silicon, that is disposed atop an insulator substrate. A gap is provided in the conductive strip and radiant energy is directed onto the exposed surface of the active layer therebeneath for the purpose of bridging the gap via a surface-generated charge carrier region. Electrical off-mode isolation in the gap is obtained by a narrow ribbon of conductive material disposed on the surface of the thin active layer at the gap between separated ends of the microstrip. This narrow ribbon is connected to a bias potential (e.g. ground), to create an isolation-enhancing depletion region in that portion of the active layer directly beneath the narrow ribbon. The thus generated depletion region provides input/output isolation in the gap between the separated ends of the microstrip. To turn the switch on, the gap is illuminated with a beam of light, in response to which electron-hole pairs in the semiconductor material of the active layer are generated. This generation of electron-hole pairs increases the carrier concentration, reduces the cross-sectional area of the depletion region and increases current flow in the gap, so that the separated ends of the microstrip are effectively electrically connected. To turn the device off, the beam of light is extinguished, cancelling the photo generated carrier and restoring the isolating depletion region.
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