Abstract of the Disclosure

The invention relates generally to the use of light coupling for electrical circuit interconnection. In a practical application of the invention, a light emitter and a light receptor are used for coupling signals between separate electrical circuits. The light emitter is a gallium arsenide PN junction device whose light output lies in the near red region of the spectrum and which is modulated in accordance with an applied signal. The light receptor is a gold compensated silicon photoconductor optimized for operation in the same spectral region and interconnected with the base of a transistor amplifier for amplification of the applied optical signal. The interconnection arrangement operates at normal ambient temperature at frequencies as high as one megacycle and is capable of unity gain.

• Figure 1 is a schematic circuit diagram illustrating a first radiative interconnection arrangement in accordance with the present invention wherein the light reception or output portion of the arrangement utilizes a photoconduction element coupled between the base and collector of a cooperating transistor element.
• Figure 3 is a schematic circuit diagram illustrating a second novel radiative interconnection arrangement wherein the output portion utilizes a photoconduction element couple between the base and emitter of the cooperating transistor element.
• Figure 4 is a schematic circuit diagram illustrating a third novel radiative interconnection arrangement wherein the output portion utilizes a pair of photoconduction elements coupled respectively between the base and collector, and the base and emitter of the cooperating transistor element.

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