Realizing Optical Chips

They can generate, detect, modulate and store light in order to receive and process high-frequency terahertz radiation - in theory. Only individual components of optical chips have yet been developed; up to complete photon-based circuits, there are still some challenges to overcome. The international doctoral student network TERAOPTICS, which is coordinated by UDE engineers, is now facing these challenges. The EU is funding the project with four million euros until 2024.

Special technology converts light into high-frequency terahertz radiation between 0.3 and 10 THz. "This technology is very promising, for example for future cellular networks, security technology or for space travel," explains Prof. Dr. Andreas Stöhr from the UDE Center for Semiconductor Technology and Optoelectronics (ZHO), who coordinates the network. PhD students from universities and research institutions around the world as well as from several European industrial companies research different aspects of the technology in 15 sub-projects.

The aim is to develop optically integrated semiconductor chips, i.e. circuits that work with photons instead of electrons. This allows THz signals to be generated more efficiently and processed more precisely - a fundamental advantage, for example, for material analysis or the transmission of high data rates by radio. "However, optical systems developed up to now are usually too complex and ultimately too expensive," says Stöhr, summarizing the initial situation.

Combine different material systems
One of the greatest challenges is the construction from different material systems, because in contrast to completely silicon-based electronic chips, the components of the optical technology need different carrier materials - and still have to function in an integrated system. There is therefore also a need for research into the design of the chips, their microstructuring, and the construction and connection technology. "The prerequisite for as many innovative solutions as possible is the ability to miniaturize an optical system and manufacture it cheaply," says the coordinator.

TERAOPTICS is the first European doctoral network coordinated by the UDE. The large number of associated partners, including the European Space Agency ESA, the European Association of the Photonic Industry, but also many start-ups and small companies, shows how great the interest in the topic is. The EU is funding the network in the Marie Skłodowska-Curie program within Horizon 2020.