A team of scientists at the Ecole Polytechnique Federale de Lausanne have developed photonic transistor used in optical circuits that require an extremely low amount of energy to operate. The small device acts as a switch that blocks or allows the flow of light in optical circuits.
The device, a photonic crystal nanostructure (PCN), was tested in an optical cavity where its “Q” factor was measured at 500,000. The “Q” factor is the measurement of how long the PCN can hold light and how many times an incoming photon will bounce back and forth inside the cavity. The high “Q” factor and small size of the device are why it requires minimal energy to act as a switch.