Researchers at the National Institute of Standards and Technology (NIST) and their colleagues have developed an optical switch that routes light from one computer chip to another in just 20 billionths of a second—faster than any other similar device. The compact switch is the first to operate at voltages low enough to be integrated onto low-cost silicon chips and redirects light with very low signal loss.
The switch’s record-breaking performance is a major new step toward building a computer that uses light instead of electricity to process information. Relying on particles of light—photons—to transport data within a computer offers several advantages over electronic communications. Photons travel faster than electrons and don’t waste energy by heating up the computer components. Managing that waste heat is a major barrier to improving computer performance. Light signals have been used for decades to transmit information over great distances using optical fibers, but the fibers take up too much room to be used to carry data across a computer chip.