Flexible terahertz devices are essential for the next generation of wearable photonics and intelligent communication systems, but mechanical deformation often leads to performance degradation. Now, researchers have developed a flexible all-optical terahertz modulator using tellurium (Te) nanofilms on polyethylene terephthalate (PET) substrates, achieving high modulation efficiency, picosecond response, low insertion loss, and robust bending tolerance. The work, published in Light: Advanced Manufacturing (DOI: 10.37188/lam.2026.086), demonstrates that these films can maintain stable performance even under repeated bending, and they enable reliable neural-network-based image recognition.
The importance of this development lies in its potential to power flexible intelligent terahertz optoelectronics. Terahertz modulators are key components for controlling terahertz signals in applications such as wearable photonics, intelligent communication, flexible imaging, and sensing. However, practical devices are often exposed to bending deformation, which can induce structural changes, information loss, or signal interruption. The new Te/PET films address this challenge by combining the unique helical chain structure, good optical response, high carrier mobility, and ambient stability of tellurium with the flexibility of PET substrates.
In their experiments, the research team, led by Professor Qingli Zhou from Capital Normal University and Professor Chen Ge from the Institute of Physics, Chinese Academy of Sciences, demonstrated that the Te/PET modulator achieves a high modulation depth of 50% on the picosecond timescale and an ultrasensitive response under low pump excitation. The device also exhibits broadband response and low insertion loss, making it a promising candidate for practical flexible terahertz systems.
To assess mechanical stability, the researchers subjected the device to repeated bending cycles and small bending radii. The transient terahertz photoresponse remained nearly unchanged, indicating that the mechanical tolerance of Te nanofilms and the flexibility of PET substrates help maintain reliable terahertz modulation during deformation. This mechanical robustness is critical for real-world applications where devices must endure physical stress.
The team further explored the information-processing capability of the device by integrating the measured terahertz modulation 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 result suggests that flexible terahertz modulators could serve as front-end functional units for intelligent sensing and neuromorphic optoelectronic systems.
“We introduce flexible Te/PET films as a mechanically robust platform for ultrafast all-optical terahertz modulation,” the scientists stated. “The stable terahertz response under different mechanical states enables reliable neural-network-based image recognition, suggesting the potential of Te-based flexible terahertz devices for intelligent sensing and wearable optoelectronic systems.”
The findings provide a new device strategy for flexible terahertz modulators and offer guidance for developing mechanically robust terahertz optoelectronic devices that operate in complex deformation environments. As flexible and wearable technologies continue to evolve, this work paves the way for integrating ultrafast terahertz modulation into intelligent systems, potentially impacting fields such as 6G communications, smart sensors, and advanced imaging.
This study was supported by several funding sources, including the National Key R&D Program of China, the Postdoctoral Fellowship Program of CPSF, the Beijing Natural Science Foundation, and the National Natural Science Foundation of China, among others. The research was published in Light: Advanced Manufacturing, with the full paper available at https://doi.org/10.37188/lam.2026.086.
