Light Instead of Wires: 3 Trillion Bits per Second express
Light can carry information faster than any electronics. But usually, between a computer and a laser sits a digital-to-analog converter — a device that turns zeros and ones into electrical signals. It's the bottleneck.
The new transmitter does away with this middleman. A laser beam passes through a flat lens with a controllable phase — a thin plate that twists light waves. At the lens's focus, ultrashort pulses are born — femtosecond flashes (one millionth of a billionth of a second). Each pulse is a bit: a bright flash means "1," a dark one means "0."
By switching the phase pattern on the lens, the authors made light itself shape the data stream. No wires, no synchronization, just light and a lens. In the experiment, they transmitted a 15-by-15-pixel black-and-white image and a color one with 9-bit encoding. The speed was about 3 trillion bits per second — a record for a single channel.
This approach removes two bottlenecks at once: slow electronics and the complex coordination between multiple devices. Light does all the work itself.
The record speed of 3 Tbit/s is about 375 gigabytes per second. In one second, you could transfer the contents of a 375 GB hard drive.
In Star Trek, data is transmitted through subspace without delays. This technology is a step toward light carrying information as freely as those fictional channels.