⚡ 6G: a measured data rate of 112 Gbps with a transmitter 90 times smaller

A Japanese team has just transmitted data at 112 gigabits per second in a frequency band of future 6G.

To achieve this data rate, the researchers used microcombs – photonic devices integrated on chips – to generate very stable optical frequencies. These microcombs significantly reduce phase noise, a major problem of conventional electronic systems at terahertz frequencies.


To overcome optical alignment difficulties, the scientists directly welded an optical fiber to a silicon nitride micror resonator. This connection avoids the delicate calibration procedures required in conventional photonic systems.

The complete system fits in a transmitter just 5 millimeters (0.2 in) in diameter – 90 times smaller than a conventional system. Additionally, an integrated thermal control function ensures stable optical resonances despite temperature variations.

The researchers plan to further improve power and reduce phase noise to achieve even higher data rates. This breakthrough paves the way for an ultra-fast wireless network compatible with the 6G rollout expected around 2030.

What is a microcomb?

A microcomb is a miniature photonic device that generates a multitude of equally spaced light frequencies, like the teeth of a comb. It relies on a ring micror resonator in which laser light circulates and produces nonlinear effects, creating a spectrum of very precise lines.

These lines serve as carriers for transmitting data. Their exceptional stability reduces phase noise, allowing the use of advanced modulations and increasing data rates.

Their main advantage is their compactness and low power consumption. However, precise alignment of the input optical fiber remains a technical challenge, resolved here by direct welding, which greatly simplifies integration into real-world systems.

Why are terahertz waves essential for 6G?

Terahertz waves occupy a frequency band between microwaves and infrared, typically from 100 GHz to 10 THz. This region offers immense bandwidth, enabling data rates far higher than those of 5G.

However, these frequencies present difficulties: atmospheric attenuation is strong, and conventional electronic components struggle to generate powerful, stable signals. Photonic systems, like the one developed here, bypass these limitations by using light to create high-quality terahertz signals.

For 6G, bands above 350 GHz are particularly promising because they are less congested. They will enable ultra-fast wireless backhaul links, avoiding the cost and complexity of underground fibers, and could also serve for augmented reality, holography, or telemedicine applications.