Cornerstone Aims for a Github for Silicon Photonics

The Cornerstone project in Southampton is focused on developing an open-source repository for silicon photonics hardware, aiming to advance the technology in collaboration with industry leaders. With STMicroelectronics reentering the silicon photonics market and Nvidia partnering with TSMC to push the boundaries of the technology, there is a growing interest in the production of such devices.

Prof Callum Littlejohn has been overseeing a 200mm silicon photonics foundry at the University of Southampton in the UK for several years. The newly funded Cornerstone commercialization center is positioned as a key hub for advancing silicon photonics technology, with a strong emphasis on open-source principles.

Littlejohn expressed, “We are now fully operational with the Cornerstone innovation center after seven years of providing foundry prototyping services. Our goal is to equip researchers for real-world applications and volume production. The majority of our work is silicon-based, making it CMOS compatible, with the exception being the integration of light sources in the final stages of the process.”

The cornerstone of the project lies in the Process Design Kit (PDK), which outlines the manufacturing process and ensures compatibility with various silicon photonics processes for seamless scalability. Littlejohn highlighted the importance of validating their open-source PDK with commercial foundries and exploring partnerships to facilitate the transition from a Cornerstone design to a foundry design.

Expanding on the PDK initiative, Littlejohn envisions creating a truly open-source PDK where external contributors can add their devices. This move towards a centralized repository, akin to a Github for photonics, aims to streamline collaboration and foster innovation within the silicon photonics community.

Looking ahead, Littlejohn plans to incorporate manufacturing data into the open-source repository, emphasizing transparency and accessibility. By engaging with companies aligned with the vision of open collaboration, he aims to leverage AI and other technologies to enhance data availability and drive industry adoption of silicon photonics.