Modern communication networks require amplified optical signals to cover long distances without losing information.
Common erbium-doped fiber amplifiers (EDFAs) enable longer data transmissions. However, they work within a limited range of wavelengths, restricting the growth of optical networks.
With the rising demand for faster data transmission, researchers are working on creating better, powerful, versatile, and compact amplifiers. AI systems and data centers are managing increasing amounts of data, but the limitations of current optical amplifiers are becoming more apparent.
EPFL and IBM Research Europe – Zurich researchers have developed a photonic-chip-based traveling-wave parametric amplifier (TWPA) that achieves ultra-broadband signal amplification in an unprecedentedly compact form. This new amplifier uses gallium phosphide-on-silicon dioxide technology to attain a net gain of over 10 dB across a bandwidth of approximately 140 nm — three times wider than a conventional C-band EDFA.
Unlike other amplifiers, which use rare-earth elements to strengthen signals, this new amplifier uses optical nonlinearity. Researchers also designed a tiny spiral waveguide to create a space where light waves reinforce each other, boosting weak signals while keeping noise low. This increased the amplifier’s efficiency and allowed it to work across a broader range of wavelengths.
Gallium phosphide has exceptional optical properties. Because of its strong optical nonlinearity, light waves passing through it can interact to boost signal strength. Its high refractive index also allows light to be confined tightly within the waveguide, leading to more efficient amplification.
Using gallium phosphide, researchers created an ultra-compact waveguide amplifier just a few centimeters long. This breakthrough enables better outcomes while significantly reducing its size. It also made the device highly suitable for future optical communication systems.
Their chip-based amplifier demonstrated impressive performance, achieving up to 35 dB of gain with minimal noise. It also amplified extremely weak signals and handled six orders of magnitude input powers. Beyond telecommunications, it could be used in precision sensing and other advanced fields.
The new amplifier significantly improved optical frequency combs and coherent communication signals, essential technologies in modern optical networks and photonics. This advancement demonstrates that photonic integrated circuits can outperform traditional fiber-based amplification systems.
Its impact extends beyond telecommunications, promising faster and more efficient data transfer for data centers, AI processors, and high-performance computing systems. Moreover, its versatility enables applications in optical sensing, precision metrology, and LiDAR systems, which are crucial for self-driving vehicles and other advanced technologies.
Journal Reference
- Kuznetsov, N., Nardi, A., Riemensberger, J., Davydova, A., Churaev, M., Seidler, P., Kippenberg, T. J. An ultra-broadband photonic-chip-based traveling-wave parametric amplifier. Nature 12 March 2025. DOI: 10.1038/s41586-025-08666-z
Source: Tech Explorist
