Tiny Laser Array Could Offer Faster, Greener Indoor Wireless

Why It Matters

The technology offers a high‑capacity, energy‑efficient alternative for indoor connectivity, easing pressure on crowded radio spectra and supporting greener data networks.

Key Takeaways

• 5×5 VCSEL array fits under 1 mm chip
• Aggregate 362.7 Gbps achieved across 21 lasers
• Energy use 1.4 nJ/bit, half Wi‑Fi consumption
• Beam‑shaping yields >90% uniform illumination at 2 m
• Multi‑user links sustain 22 Gbps without interference

Pulse Analysis

Optical wireless communication is emerging as a practical complement to congested radio‑frequency bands, especially in dense indoor environments where spectrum scarcity and interference limit Wi‑Fi and cellular performance. By exploiting the vastly higher carrier frequencies of infrared light, a single link can carry orders of magnitude more data while remaining invisible to existing RF equipment. Recent advances in vertical‑cavity surface‑emitting lasers (VCSELs) have made it possible to place dozens of coherent light sources on a sub‑millimetre chip, turning the concept of a room‑scale photonic network into a manufacturable reality.

The Cambridge‑Manchester team demonstrated a 5 × 5 VCSEL array, each element individually addressable, delivering between 13 and 19 Gbps per laser and a combined throughput of 362.7 Gbps over a two‑metre free‑space link. A compact microlens system collimates and redistributes the beams into a grid of square spots, achieving more than 90 percent illumination uniformity and preventing cross‑talk between adjacent channels. Multi‑beam operation proved stable, with four simultaneous links sustaining 22 Gbps, while the transmitter consumed only 1.4 nJ per transmitted bit—roughly half the energy budget of contemporary Wi‑Fi solutions.

These results point toward a new class of energy‑efficient indoor backbones that can offload traffic from overloaded RF networks, particularly in offices, factories, and data‑center aisles where high‑capacity, low‑latency links are critical. Integration into ceiling fixtures or smart lighting could provide ubiquitous coverage without additional spectrum licensing, while the chip‑scale form factor eases retrofitting of existing infrastructure. As photodetector bandwidth catches up, the same architecture could push aggregate rates into the terabit‑per‑second regime, offering a scalable path for future 6G and beyond connectivity while reducing the carbon footprint of wireless data delivery.