Combining optical and microwave signal processing on a single silicon chip the research groups have integrated high-speed modulators, optical filters, photodetectors, as well as transfer-printed lasers, making a compact, self-contained and programmable solution for high-frequency signal processing.
This breakthrough will help to replace bulky and power-hungry components, enabling faster wireless networks, low-cost microwave sensing, and scalable deployment in applications like 5G/6G, satellite communications, and radar systems. The results have been published in Nature Communications.
Modern communication networks rely on both high-speed fibre-optic links and wireless radio-frequency microwave transmission, but with demand for higher data rates and operation at higher frequencies growing rapidly, new systems need much tighter integration between these two modes of communication to overcome the struggle with signal processing complexity, high transmission losses, and power-hungry electronics.
Microwave photonics is seen as offering a promising solution by using optical technology to process high-frequency signals with lower loss, higher bandwidth, and improved energy efficiency. However, most microwave photonics systems rely on bulky, fibre-based architectures that limit scalability.
In contrast integrating microwave photonics onto a chip could enable more scalable and power-efficient systems, but early experimental demonstrations have either lacked key functionalities or required external components to achieve full performance.
Imec and Ghent University have now been able to demonstrate a silicon photonic engine that processes and converts both optical and microwave signals on a single chip.
The key innovation in this system lies in the combination of a reconfigurable modulator and a programmable optical filter enabling efficient modulation and filtering of microwave signals while significantly reducing signal loss. This is a unique combination that enhances overall performance and allows the system to handle complex signal processing tasks with greater flexibility and efficiency for a wide range of applications.
The chip is built on imec’s standard iSiPP50G silicon photonics platform, which includes low-loss waveguides and passive components, high-speed modulators and detectors, and thermo-optic phase shifters for tuning the optical response. To provide an integrated light source, the researchers incorporated an indium phosphide (InP) optical amplifier (developed by III-V Lab) on the chip using the microtransfer-printing technology developed at the Photonics Research Group (imec/Ghent University). In combination with on-chip tunable filter circuits, this allows the optical amplifier to function as a widely tunable laser, further enhancing the system’s versatility.
“The ability to integrate all essential microwave photonics components on a single chip marks a major step toward scalable and energy-efficient high-frequency signal processing,” said Wim Bogaerts, professor in the Photonics Research Group at Ghent University and imec. “By eliminating bulky external components, this technology paves the way for more compact, cost-effective solutions in next-generation wireless networks and advanced sensing systems.”
