Photonex 2023: keynote investigates continuing potential of silicon photonics

26 Oct 2023

Wednesday’s session offered a diverse and optimistic update on evolving SiPh technology.

Silicon photonics has been one of the key strands at this week’s SPIE Photonex conference and exhibition in Glasgow, UK. On Wednesday morning, the session “Emerging Applications in Silicon Photonics IV” was introduced by co-chair Callum Littlejohns, of the University of Southampton.

He told the audience that the session would address key questions, what is silicon photonics for? and where is it going? covering the ongoing issues of: electronic-photonic integration and convergence; the development of more advanced devices; new platforms enabled by different semiconductor combinations and the introduction of novel compound semiconductors and doped crystalline structures.

The well-attended keynote presentation was given by silicon photonics expert Dr. Laurent Vivien, from the Center of Nanosciences and Nanotechnologies, France.

Dr Vivien is CNRS Director of Research at the Centre for Nanoscience and Nanotechnology (C2N), a joint Laboratory of CNRS, University of Paris Sud and University of Paris Saclay.

His talk acknowledged that the silicon photonics platform, which has been commercially active over the past two decades, has undergone substantial development to tackle diverse applications, including datacom, sensing, and optical communications.

‘Overcoming limitations’

“Numerous efficient devices and circuits have been proposed, and products are widely available in the market. However, the intrinsic properties of silicon-based materials do not fully overcome the limitations in terms of speed, power consumption and scalability,” he said.

As a result of this, new strategies have emerged, mainly focusing on the integration of new materials with silicon photonics and the exploitation of nonlinear optical properties.

Dr. Vivien identified a range of new and potential application areas for silicon photonics that various groups are working towards. From established technologies for data- and telecoms, data centers and sensing, the silicon photonics sector is now moving towards advanced datacoms with all-optical processing and silicon photonics-based inter processor links, he said.

“Diversified applications that will form the basis of industrial silicon photonics of tomorrow include optical gyroscopes, mid-infrared spectroscopy, free-space optics, AI and neuromorphic applications, quantum technologies, chemical analysis, lidar and diagnostics,” he said.

These developments will be enabled and enhanced by the further development of silicon photonics’ integration with compound semiconductor materials including LiNbO₃, AlGaAs, AlN, Al₂O₃, SiC, and GaN, to name a few. Dr. Vivien also described the potential benefits of integration with “rare earth” dopants in combination with ZrO₂.

His group in France, at University of Paris, Saclay, is continuing to work on new applications and combinations with silicon photonics. “New paradigms of silicon photonics include monolithic, hybrid, heterogeneous integration, and nonlinear optics,” he said.

“New platforms include investigating nonlinear functionalities with Kerr and Pockels effects, light amplification, based on new materials.” He concluded that doped crystalline oxides are a promising platform.