Monash University researchers have placed three optical functions on a single chip, reporting in Nature Photonics in June 2026 that the device can generate, route and read valley-polarised photons at room temperature. The team demonstrated the system by encoding two separate images onto the chip at once.

What did the researchers actually build?

The device pairs materials a few atoms thick with engineered metasurfaces that control the valley degree of freedom, a quantum property tied to energy extrema in a crystal's band structure. Until now, no integrated circuit could create, steer and read these signals in one system.

Lead author Chi Li, of the Monash School of Physics and Astronomy, described the gap. "Until now, we could generate or detect these signals, but not do everything in one integrated device," Li said. "What we have built is a complete on-chip system that can create, route and read this information with very high precision."

Why does room-temperature operation matter?

Most quantum photonic platforms demand cryogenic cooling, which inflates system cost and footprint. The Monash device operates at ambient conditions because it relies on stacked two-dimensional materials rather than on superconducting emitters.

Senior author Haoran Ren, an ARC Future Fellow, framed the architectural advantage. "This is a significant step toward scalable, chip-based technologies that use light instead of electricity to process information," Ren said. The team expects the platform to deliver higher bandwidth and lower energy consumption than systems that process information electrically.

How do the components fit together?

Co-first author Kaijian Xing explained the fabrication method. "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.

Stacking places the active layer above the metasurface rather than embedding it in a patterned substrate, a configuration the team says overcomes long-standing growth difficulties in the field.

What applications does the team see?

The two-image encoding experiment shows the device can manage multiple streams of information at once. Ren listed three targets: quantum computing, advanced imaging, and next-generation optical communications.

Who else contributed?

The collaboration spans five countries: Australia, China, Singapore, Germany and Japan. Co-authors include Michael S. Fuhrer of Monash, Luca Sortino and Andreas Tittl of LMU Munich, and Kenji Watanabe and Takashi Taniguchi, the long-time suppliers of hexagonal boron nitride crystals used in two-dimensional material research. The Singapore University of Technology and Design and the University of Technology Sydney also contributed.

What comes next?

The paper positions the device as a programmable building block rather than a finished product. Scaling will require yield improvements in the stacking process, a familiar challenge for any wafer-scale two-dimensional technology. The next eighteen months will determine whether a foundry partnership materialises and whether the team publishes benchmarks on insertion loss, which the present paper does not disclose.