Researchers find clever solution that makes all data centers faster

Researchers have developed a photonic switch smaller than a grain of salt that can redirect light signals in trillionths of a second. This innovation could significantly speed up data transfer in data centers.

Grain of salt switch in the data center

The novel switch, developed by engineers at the University of Pennsylvania, is smaller than a grain of salt, measuring just 85 x 85 micrometers. Despite its small size, it can redirect light signals in a very short time – trillionths of a second.

For comparison: This switching time is about a billion times faster than the blink of an eye. “Previous switches have been either small or fast, but it is very, very difficult to combine these two properties,” the team said. The special feature of the switch lies in the application of non-Hermitian physics, a complex branch of quantum mechanics.

This makes it possible to precisely control light at the nano level. In practice, this means that data in the form of light signals can be passed quickly and efficiently through tiny optical circuits. Similar to how traffic lights regulate traffic, these switches in data centers control the flow of data and ensure that information reaches its destination in an orderly manner.

“This has the potential to accelerate everything from streaming movies to training artificial intelligence,” Liang Feng, lead author of the study

Difficult to build

The switch is made of a combination of materials that make it particularly promising: thanks to a layer of silicon, a cost-effective basis, it is compatible with existing manufacturing processes. An additional layer of indium gallium arsenide phosphide (InGaAsP) makes the effective manipulation of infrared light possible.

This infrared light is often used in optical data transmission. Like the researchers in the Study in Nature Photonics report, it was a particular challenge to connect the two layers of material together. Accordingly, a functioning prototype could only be produced after countless attempts. What is an optical switch? An optical switch is a network device that processes and forwards light signals. It receives data over fiber optic cables in the form of light pulses.

What is special about optical switches is their ability to process the signals with extremely low latency – the entire process takes place in nanoseconds. How does signal conversion work? The signal conversion takes place in the SFP (Small Form-factor Pluggable) transceiver. A photodiode converts the incoming light pulses into electrical signals. This conversion is necessary because the actual data processing takes place electronically.

The electrical signals are then prepared for further processing. Which wavelengths are used? Three different wavelengths are typically used in optical networks: 850 nanometers, 1310 nanometers and 1550 nanometers. These specific wavelengths were chosen because they are particularly suitable for transmission in optical fibers and have minimal losses.

How does the processing work? The switch ASIC (Application-Specific Integrated Circuit) processes the incoming data packets and analyzes their headers. The destination port is determined using the MAC address table. Meanwhile, the packets are temporarily stored in internal buffers before they are forwarded via the corresponding output port.