Computers may be getting faster every year, but those advances in computer speed could be dwarfed if their 1’s and 0’s were represented by bursts of light, instead of electricity. Researchers at the University of Pennsylvania have made an important advance in this frontier of photonics, fashioning the first all-optical photonic switch out of cadmium sulfide nanowires. Moreover, they combined these photonic switches into a logic gate, a fundamental component of computer chips that process information. The research team began by precisely cutting a gap into a nanowire. They then pumped enough energy into the first nanowire segment that it began to emit laser light from its end and through the gap. Because the researchers started with a single nanowire, the two segment ends were perfectly matched, allowing the second segment to efficiently absorb and transmit the light down its length. “Putting switches together lets you make logic gates, and assembling logic gates allows you to do computation,” Piccione said. “We used these optical switches to construct a NAND gate, which is a fundamental building block of modern computer processing.” “We see a future where ‘consumer electronics’ become ‘consumer photonics".