Flexible terahertz devices are critical for the advancement of wearable photonics and intelligent communication systems, but mechanical deformation often leads to performance degradation. A new study introduces tellurium (Te) nanofilms grown on polyethylene terephthalate (PET) substrates as a solution, achieving high modulation efficiency and picosecond response while maintaining robustness under bending. This development addresses a key challenge in flexible terahertz technology, offering a pathway to devices that can withstand real-world mechanical stress.
The research, published in Light: Advanced Manufacturing, was led by Professor Qingli Zhou from Capital Normal University and Professor Chen Ge from the Institute of Physics, Chinese Academy of Sciences. The team demonstrated that Te/PET films exhibit a modulation depth of 50% on a picosecond timescale, with low insertion loss and broadband operation. These characteristics are attributed to Te's unique helical chain structure, high carrier mobility, and ambient stability, which are preserved when integrated with the flexible PET substrate.
To assess practical viability, the researchers subjected the devices to repeated bending cycles and small bending radii. Remarkably, the transient terahertz photoresponse remained nearly unchanged, indicating excellent mechanical tolerance. This stability is due to the combined flexibility of the PET substrate and the mechanical resilience of the Te nanofilms, which maintain reliable terahertz modulation even under deformation.
Beyond basic modulation, the team explored the device's potential in intelligent systems by integrating the measured terahertz response into an artificial neural network (ANN) for image recognition. The recognition accuracy remained stable under different bending conditions, demonstrating that the mechanical robustness translates into reliable information processing. This suggests that flexible terahertz modulators could serve as front-end units in intelligent sensing and neuromorphic optoelectronic systems.
The scientists summarized their findings, noting that the device exhibits broadband response, low insertion loss, and high modulation efficiency, while maintaining performance under bending. They further highlighted that the stable terahertz response enables reliable neural-network-based image recognition, pointing to the potential for Te-based flexible devices in intelligent sensing and wearable optoelectronics. The results provide a new strategy for designing flexible terahertz modulators and offer guidance for developing mechanically robust terahertz devices for complex environments.
The study was supported by several funding sources, including the National Key R&D Program of China and the National Natural Science Foundation of China. For more information, the original source is available at https://doi.org/10.37188/lam.2026.086.
