Researchers at the University of Cambridge have unveiled a chip-scale optical wireless system capable of delivering aggregate data rates exceeding 360 Gb/s while using roughly half the energy per bit of conventional Wi-Fi.
Published in Advanced Photonics Nexus, the platform integrates a 5×5 array of vertical-cavity surface-emitting lasers (VCSELs) with custom beam-shaping optics to enable high-speed, energy-efficient indoor wireless links.
Optical wireless communication transmits data via light instead of radio frequencies, offering access to a broader spectrum and avoiding radio interference. Historically, achieving high throughput, energy efficiency, and scalable deployment simultaneously has been challenging.
The Cambridge system addresses this by parallelizing the transmitter: each of the 25 lasers can be independently modulated to send multiple data streams at once. In tests, 21 lasers were active, delivering 13–19 Gb/s per channel and a combined throughput of 362.7 Gb/s over a two-meter free-space link. The system employs orthogonal frequency-division multiplexing (OFDM) to maximize spectral efficiency, a method adapted from radio communications for optical use.
To manage beam interference, the researchers developed a compact optical assembly that structures the light into a grid of square illumination zones. At two meters, over 90% uniformity was achieved, allowing different beams to serve separate users. In a multi-user test with four beams, the system maintained stable links at a combined 22 Gb/s.
Energy efficiency is a major advantage: the setup consumed roughly 1.4 nanojoules per bit, about half that of state-of-the-art Wi-Fi, thanks to the VCSELs’ high-speed, low-power modulation capability.
The team notes that the current system is limited by the commercial photodetector used, and higher data rates are achievable with more advanced receivers. The demonstration relies on a controlled two-meter link and precise optical alignment, highlighting the gap between laboratory results and real-world deployment.
Despite these limitations, the work points to a promising future for optical wireless technology as a complementary layer to Wi-Fi, capable of offloading traffic in high-density environments such as offices, data centers, and public venues.
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