Modern internet and communication networks rely on light signals to transfer massive amounts of data.
However, just like a weak radio signal, these light signals need to be strengthened to travel long distances without losing information.
For decades, fiber-optic amplifiers—specifically erbium-doped fiber amplifiers (EDFAs)—have done this job, allowing data to travel further without needing frequent boosting.
But these amplifiers have a problem: they only work within a limited range of light wavelengths, restricting the growth of optical networks.
As demand for faster data speeds increases, scientists have been searching for better amplifiers that are powerful, efficient, and compact.
While some alternative solutions, like Raman amplifiers, exist, they are too complex and consume too much energy.
Now, a team of researchers led by Tobias Kippenberg at EPFL and Paul Seidler at IBM Research Europe—Zurich has developed a groundbreaking photonic-chip-based amplifier.
This tiny device, called a traveling-wave parametric amplifier (TWPA), dramatically boosts light signals over a much wider range of wavelengths than traditional amplifiers.
The new amplifier, built using gallium phosphide-on-silicon dioxide technology, can amplify signals across 140 nanometers of bandwidth—three times wider than standard fiber amplifiers.
Instead of relying on rare-earth elements like erbium, it uses a special optical effect where light interacts with itself to strengthen weak signals.
By carefully designing a tiny spiral-shaped waveguide, the scientists created an environment where light waves reinforce each other, making the signal stronger while keeping noise levels low.
Gallium phosphide was chosen because it has excellent optical properties, including high nonlinearity (which helps light boost itself) and a high refractive index (which keeps light tightly confined for efficient amplification).
Despite being just a few centimeters long, the chip-based amplifier can achieve up to 35 dB of gain while working with extremely weak signals. This makes it not only a game-changer for the internet and data centers but also useful for precision sensing, LiDAR in self-driving cars, and advanced scientific instruments.
The research, published in Nature, shows that this tiny amplifier could replace bulky, fiber-based systems, making next-generation optical networks faster, more efficient, and ready for the future.
