In a groundbreaking advancement for terahertz technology, researchers at the University of Manchester have developed a large-scale reconfigurable intelligent surface capable of dynamically controlling terahertz (THz) and millimeter waves. This technology utilizes graphene-based modulators integrated with thin-film transistors (TFTs) to create an innovative spatial light modulator featuring over 300,000 individually addressable subwavelength pixels.
The ability to programmably alter reflection and transmission patterns of THz light on such a large scale opens new avenues for applications in communications, imaging, and sensing. The findings of this research were prominently showcased on March 25, 2025, demonstrating the potential of THz technologies to deliver versatile solutions to ongoing challenges.
Despite the promise offered by the THz spectrum—ranging from 0.3 to 3 THz—its potential has remained largely untapped due to the historical development of suitable materials and devices. By effectively utilizing graphene, a material known for its exceptional electronic properties, researchers have taken a significant step toward overcoming these barriers. The newly designed modulator allows for electronically programmable reflection and transmission patterns across a vast area, achieving unprecedented levels of uniformity and reproducibility, as indicated by the research.
In the experimental setup, an active-matrix technology controls local voltage for each of the 640 rows and 480 columns of pixels, covering a surface area of 12 x 9 cm2. This technology not only enhances efficiency but also renders the modulation of THz waves practical and scalable for commercial applications.
One of the exciting applications of this modulator is its capability to function as a single-pixel mm-wave camera, which can image concealed metallic objects. The imaging process is powered by a compressed sensing algorithm that reconstructs spatial information from unique transmission patterns generated by the modulator. Initial prototypes successfully imaged objects like wrenches and razor blades, showcasing resolutions determined by the wavelength of the THz light used.
Furthermore, to highlight the modulator's capabilities, the researchers reported features such as dynamic beam steering, which allows manipulation of the direction and shape of THz beams. Excitingly, applying various binary grating patterns led to the production of distinct diffracted beams with adjustable angles, expanding the potential for future THz applications in communication and sensing technologies.
The researchers included a notable remark in their publication, stating, "We anticipate that these results will provide realistic pathways to structure THz waves for applications in non-invasive THz imaging and next generation THz communications." This statement reflects the optimism surrounding the modulation technologies as they advance toward practical integration in real-world scenarios.
In summary, the confluence of graphene-based technology and TFTs set a new standard in programmable THz devices, showcasing impressive modulation performances. As this field progresses, applications in security, medical imaging, and industrial inspection seem poised to benefit immensely from these cutting-edge developments. Further enhancements, including improvements in operational speed and efficiency, could soon unfold, promising a more connected future utilizing terahertz technology.
