Harnessing electromagnetic waves and quantum materials to improve wireless communication technologies

A team of researchers from the University of Ottawa has developed innovative methods to enhance frequency conversion of terahertz (THz) waves in graphene-based structures, unlocking new potential for faster, more efficient technologies in wireless communication and signal processing.

THz waves, located in the far-infrared region of the electromagnetic spectrum, can be used to perform non-invasive imaging through opaque materials for security and quality control applications. Additionally, these waves hold great promise for wireless communication. Advances in THz nonlinear optics, which can be used to change the frequency of electromagnetic waves, are essential for the development of high-speed wireless communication and signal processing systems for 6G technologies and beyond.

THz technologies are rapidly evolving as they are poised to play a critical role in health, communication, security, and quality control. Jean-Michel Ménard, Associate Professor of Physics from the Faculty of Science and a team of researchers have paved the way for developing devices capable of upconverting electromagnetic signals to higher oscillation frequencies, effectively bridging the gap between GHz electronics and THz photonics.

These findings – published in Light: Science & Applications – demonstrate innovative strategies for enhancing THz nonlinearities in graphene-based devices. “The research marks a significant step forward in improving the efficiency of THz frequency converters, a critical aspect for multi-spectral THz applications and especially the future of communication systems, like 6G,” says Professor Ménard, who collaborated on the project with fellow uOttawa researchers Ali Maleki and Robert W. Boyd, plus Moritz B. Heindl and Georg Herink from the University of Bayreuth (Germany) and Iridian Spectral Technologies.

This new research showcases methods to leverage the unique optical properties of graphene, an emerging quantum material made of a single layer of carbon atoms. This 2D material can be seamlessly integrated into devices, enabling new applications for signal processing and communication.

Previous works combining THz light and graphene primarily focused on fundamental light-matter interactions, often examining the effect of a single parameter in the experiment. The resulting nonlinear effects were extremely weak. To overcome this limitation, Professor Ménard and his colleagues have combined multiple innovative approaches to enhance nonlinear effects and fully leverage graphene’s unique properties.

“Our experimental platform and novel device architectures offer the possibility to explore a vast range of materials beyond graphene and potentially identify new nonlinear optical mechanisms,” adds Ali Maleki, a PhD student in the Ultrafast THz group at uOttawa, who collected and analyzed results for the study.

“Such research and development are crucial for refining THz frequency conversion techniques and eventually integrating this technology into practical applications, particularly to enable efficient, chip-integrated nonlinear THz signal converters that will drive future communication systems.”