Bulletin No. 2, 2024

speed you like and you can go long distances without loss.” This area of academic study, known as silicon photonics, has become increasingly relevant with the ever-increasing amounts of information being transmitted every day. Back when the professor first focused on the subject in the late 1990s, “you could literally, with one batch of wafers, supply the whole of the world with the wavelength division routers that telecom systems needed, and it was commercially unviable for a company to run a semiconductor fabrication facility just for silicon photonics products for the limited telecom market.” But since then, he explains, optical interconnects for computers have become mainstream technology, and now there exist many new silicon photonics fabrication foundries. It is therefore now possible for a company to become established without having a fabrication facility of its own, following the well-established fabless design house business model in the microelectronics industry. In the last 20 years, the professor has steadily built on his research, contributing to the latest technologies in the field. Today, just as the digital world grows ever more information-hungry, his research on silicon photonics has proven to be a serendipitous career choice. Many hands make light work Professor Tsang’s expertise is not merely limited to the world of academia: he was previously director of R&D at Bookham Technology plc, a UK-based startup which at its peak valuation had a market capitalisation that ranked it among the top FTSE- 100 companies. This brief detour into the world of business seeded the vision for the startup with his CUHK research team this year, one which focused on perfecting the design of silicon photonic chips. “What we are trying to do here is to form a startup company which is focused on our core strength of silicon photonics design, and to work with existing companies, introducing them to some of our latest technology that may help them to reduce product costs and improve the performance of the products by having a chip that is robust to mechanical vibration.” This emphasis on product design, he notes, is similar to “fabless” microelectronic companies like Qualcomm and Nvidia. His efforts caught the eye of committee members of the RAISe+ Scheme. Professor Tsang’s application was shortlisted for interview in early 2024, and his team was quickly selected for funding approval in principle in May this year. They named their firm “OptiHK”, a play on the German word optik that also emphasises its local roots; although the company is now still in its infancy, the professor is optimistic about its prospects, raising the example of semiconductor giant Qualcomm: “today it’s a $170-billion company, but they started with seven people in 1985. They had a lot of IP on the wireless mobile phone and wireless chipset, and we hope to be in a similar position with the technology for the silicon photonics industry.” Professor Tsang converses with one of the students in his research team | Professor Tsang Hon-ki Chinese University Bulletin 24