LEUVEN (Belgium), 5 June, 2025— This month, the Photonics Research Group
and IDlab, two imec research groups at Ghent University, and imec, a
world-leading research and innovation hub in nanoelectronics and digital
technologies, have published the demonstration of a fully-integrated
single-chip microwave photonics system, combining optical and microwave
signal processing on a single silicon chip. The chip integrates
high-speed modulators, optical filters, photodetectors, as well as
transfer-printed lasers, making it a compact, self-contained and
programmable solution for high-frequency signal processing. This
breakthrough can 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 fiber-optic links
and wireless radio-frequency microwave transmission, but as demand for
higher data rates and operation at higher frequencies grows, 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
offers 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, fiber-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 now demonstrate a silicon photonic engine that
processes and converts both optical and microwave signals on a single
chip. The key innovation in this new system lies in the novel
combination of a reconfigurable modulator and a programmable optical
filter enabling efficient modulation and filtering of microwave signals
while significantly reducing signal loss. This unique combination
enhances overall performance allowing 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.”