This experimental set-up was used to show that it is possible to make a transistor that acts using laser beams, not electric currents (Image: Martin Pototschnig)
From New Scientist:
An optical transistor that uses one laser beam to control another could form the heart of a future generation of ultrafast light-based computers, say Swiss researchers.
Conventional computers are based on transistors, which allow one electrode to control the current moving through the device and are combined to form logic gates and processors. The new component achieves the same thing, but for laser beams, not electric currents.
A green laser beam is used to control the power of an orange laser beam passing through the device.
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