Researchers demonstrate noise-free communication with structured light

Newswise — A groundbreaking advancement has been made by researchers at the University of the Witwatersrand (Wits) in the field of optical communications. They have developed a novel optical communication protocol that capitalizes on spatial patterns of light to enable multi-dimensional encoding. This innovative approach eliminates the need for pattern recognition, thus overcoming the challenges posed by distortion in noisy channels, such as atmospheric turbulence or bent optical fiber.

The outcome of this research is an impressive state-of-the-art encoding technique that encompasses more than 50 vectorial patterns of light. Remarkably, these patterns can be transmitted across a turbulent atmosphere with minimal noise interference. This significant breakthrough opens up a new avenue for high-bit-rate optical communication, with the potential to revolutionize the field.

A team of researchers from the Structured Light Laboratory in the Wits School of Physics made an interesting discovery. They found a new property of light called "vectorness" that can be used to store information. This property ranges from 0 to 1 and doesn't change even when the light passes through a noisy channel. Unlike the traditional method of encoding information with only two options (0 or 1), the team divided the range of vectorness into more than 50 parts, creating a 50-letter alphabet. This means they can transmit information without any errors caused by noise because both the sender and receiver will always agree on the value of vectorness.

The team managed to solve a significant problem by using light patterns in a way that doesn't rely on recognizing them. This allowed them to ignore the distortion caused by noisy channels. Instead, they found a way to measure the total amount of light in a specific manner that reveals a quantity unaffected by the distortion. In other words, they found a way to work with the light that doesn't care about the distortion caused by the noisy channels.

"This is a really exciting breakthrough because now we can use various light patterns as an encoding system without being concerned about the level of noise in the channel," says Professor Andrew Forbes from the Wits School of Physics. "The size of the encoding system is only limited by the quality of the detectors and not affected by the noise in the channel at all."

Keshaan Singh, the main author and a PhD candidate, adds, "To use the vectorness modulation for creating and detecting signals, we don't need any special communication technology. This means that our pattern-based protocol can be used right away in real-world situations."

The team has already begun showing how their method works using optical fiber and fast links in open space. They are confident that this approach can be used in other noisy channels, such as underwater communication.