Monash team demonstrates room-temperature photonic circuit

Researchers from Monash University have developed a nanoscale circuit that can generate, direct and read light-based information, all on a single chip.

The new technology, developed by scientists in the Monash School of Physics and Astronomy, brings together cutting-edge materials and nanotechnology to overcome a longstanding challenge in “valleytronics”, an emerging field that could underpin faster, more energy-efficient computing and quantum technologies.

The researchers have demonstrated a fully integrated system that can generate special light signals, guide them in precise directions, and convert them into electrical signals, all within a compact, chip-based device.

These light signals carry information using a property known as the “valley degree of freedom”, a quantum characteristic of materials that can be harnessed to encode and process data in entirely new ways.

Lead author of the study published in Nature Photonics Dr Chi Li said the development solves a key bottleneck that has limited the field for years.

“Until now, we could generate or detect these signals, but not do everything in one integrated device. What we’ve built is a complete on-chip system that can create, route and read this information with very high precision,” Li said.

Dr Kaijian Xing, co-first author and Research Fellow at Monash University, said the device works by using ultra-thin materials, just a few atoms thick, combined with specially designed nanostructures that control how light behaves at extremely small scales.

“We employ a straightforward stacking approach to integrate ultra-thin materials with metasurfaces, overcoming the technical challenges of direct material growth on photonic structures, and enabling further advances in valleytronics,” Xing said.

Importantly, the system operates at room temperature, making it far more practical than many quantum technologies that require extreme cooling.

Senior author Dr Haoran Ren said the work opens the door to a new class of compact, programmable photonic devices, and could enable faster and more energy-efficient computing systems, as well as new approaches to secure communications and data processing.

“This is a significant step toward scalable, chip-based technologies that use light instead of electricity to process information,” Ren said.

“Photonic devices use light to achieve massive bandwidths, ultra-fast data transmission speeds and lower energy consumption, so what we have achieved has strong potential for applications in quantum computing, advanced imaging and next-generation optical communication systems.”

The team successfully encoded and processed two different images simultaneously using the device, showing how it can handle multiple streams of information at once.

Image caption: An artist’s illustration of a photonic valleytronic chip for information processing. Image credit: Chi Li.