Abstract :
If electroluminescent cells and photoconductor cells are placed in optical vicinity, the combination can be used as a power amplifier for electrical signals. Whereas in vacuum tubes control is exerted by an electric field, and in magnetic amplifiers by a magnetic field, this new amplifier type uses light as a control medium. Static power gains up to 40 db have been readily achieved, although the frequency response is, at present, not satisfactory for audio purposes. Means of feedback can be provided, which raise the power gain to any desired level, until bistability is reached. In this form, the device becomes a possible future computer component, which can be acted upon optically, electrically, or mechanically. The paper shows the construction of such components, some of their operating characteristics, and an approximate mathematical analysis.