Doctoral Network harnesses silicon carbide to power a new era of photonic chips

In high demand

Photonic integrated circuit (PIC) technology is an enabling technology, deemed to address the challenges faced by microelectronic integrated circuits such as high power consumption and large resistive-capacitive delay caused by the line width reduction.

The demand for the technology is at an all-time high, and it is expected to experience a steadily accelerating adoption across markets.

However, the potential of PIC is not fully demonstrated in the existing material platforms yet. Silicon carbide (SiC), an emerging wide band-gap semiconductor, is promising to advance PIC technology and accelerate its wide market adoption.

Societal impact

SiCOI PIC’s low-cost, compact size, and superior performance make it suitable for a variety of applications, such as information processing, optical communication, power electronics, bio/chemical sensing, searching for exoplanets, and quantum computing amongst others.

For example, SiCOI PIC can improve the performance of communication networks, enabling faster and more reliable data transmission. Additionally, it can be used to improve the accuracy of medical devices and instruments, leading to better diagnoses and treatments.

SiCOI PIC’s material abundance and sustainability could lead to more efficient use of resources in a variety of industries, such as manufacturing and transportation. This could result in reduced waste and energy consumption, leading to a lower overall carbon footprint.

Scientific impact

SiCPIC will develop low-loss, low-cost SiCOI stacks using different SiC polytypes and amorphous SiC – materials vital for nanophotonics, quantum photonics, MEMS, and biophotonics.

Thanks to SiC’s unique optical and physical properties, the SiCPIC platform can host versatile devices. Its strong second- and third-order nonlinearities enable frequency doubling, electro-optic modulators, and optical frequency combs. By integrating these functions on a single SiCOI platform, SiCPIC enables unprecedented compactness and low power consumption. With its wide bandgap, SiC transmits from near-UV to mid-IR, allowing visible frequency combs via doubling and mid-IR combs via Raman scattering.

Beyond classical photonics, SiCPIC will leverage SiC’s single-photon emitters for scalable, room-temperature quantum photonics – a major step toward real applications.

With broad scalability and market relevance, SiCPIC has strong commercialization potential. Optical frequency combs, a disruptive technology, are projected to grow 2–7% in the next five years, driven by big data centers, environmental sensing, trend towards reduced energy consumption, and sustainable materials.

Prospects

Ou’s FET-OPEN project SiComb (2020-2024) was the first European project to explore the potential of SiC in integrated photonics. In SiComb, she and her team developed: methods to form silicon carbide on insulator stacks patented; methods to characterize the material loss in SiC thin films; a nanofabrication method to achieve low loss SiC waveguides; and chemical mechanical polishing to reduce the top surface roughness. From this, they demonstrated four-wave mixing, optical parametric oscillation and Kerr comb at telecom wavelength range and Raman comb at longer wavelength range.

These SiComb results represent the state-of-the-art and lay a solid foundation for the SiCPIC Doctoral Network.

In SiCPIC, the team aims to demonstrate integration of the most important building blocks (optical frequency combs, modulators, arrayed waveguide gratings), pioneering in this field, and package the SiC chips and apply them for optical communication, mid-infrared spectroscopy and quantum communication.