Researchers from the Pohang University of Science and Technology (POSTECH), Ajouu University, and Inha University have come up with a new approach to light-based networking — which, they say, could boost "Li-Fi" speeds to 100 times what is achievable by radio-frequency Wi-Fi.
"A multichannel/multicolor visible light communication (VLC) system using entirely organic components," the team explains of its work, "including organic light emitting diodes (OLEDs) and organic photodiodes (OPDs), is developed to demonstrate indoor lighting applications where the integration of OLEDs and OPDs has significant potential. Utilizing […] spectrally refined tricolor OPDs/OLEDs, a VLC system is designed for indoor lighting applications."
"Li-Fi" has the potential to be the next big step for indoor wireless communications, replacing the radio-frequency transmissions of Wi-Fi and Bluetooth networking with imperceptible flickers of visible light — integrated, in many designs, in existing building lighting systems. Existing Li-Fi systems using power-efficient LEDs, though, struggle with cancellation issues when matching-wavelength light beams interact — which is where the team's creation comes in.
By replacing single-color LEDs with red, green, and blue organic light-emitting diodes (OLEDs), the team was able to create a light source which looks like standard white lighting to the human eye but which avoids the interference issues inherent in true single-color light sources. Combined with a Fabry-Pérot structure — tailored to transmit only chosen wavelengths and reflect the rest of the light — in the light-absorbing organic photodiodes (OPDs) which serve as the receiving side of the system, the result is a Li-Fi network with a much lower bit error rate (BER) than the competition — potentially boosting the achievable throughput to 100 times that of Wi-Fi networks.
"In contrast to conventional light sources, our light source, which blends three wavelengths, circumvents interference thereby enhancing stability and accuracy in data transmission," Dae Sung Chung, project lead and professor at POSTECH's Department of Chemical Engineering, explains. "We foresee this technology as a potentially beneficial tool for diverse industries, serving as a next-generation wireless communication solution that utilizes conventional lighting systems."
The team's work has been published in the journal Advanced Materials under closed-access terms.