Flexible terahertz devices are essential for the advancement of wearable photonics and intelligent communication systems, yet their practical deployment has been hindered by a critical challenge: mechanical deformation can lead to information loss and signal interruption. To address this, a research team led by Professor Qingli Zhou from Capital Normal University and Professor Chen Ge from the Institute of Physics, Chinese Academy of Sciences, has developed flexible Te/PET films that serve as ultrafast all-optical terahertz modulators with high modulation efficiency, picosecond response, low insertion loss, and robust bending tolerance. Their findings are published in Light: Advanced Manufacturing.
Terahertz modulators are key components in controlling terahertz signals for applications such as flexible imaging, sensing, and intelligent communication. However, conventional devices often fail when subjected to bending, which can induce structural changes and degrade performance. The new Te/PET films leverage the unique properties of tellurium, including its helical chain structure, good optical response, high carrier mobility, and ambient stability. When integrated with flexible polyethylene terephthalate substrates, these films form mechanically robust and optically active layers suitable for terahertz modulation.
The device demonstrates a high modulation depth of 50% on the picosecond timescale and an ultrasensitive response under low pump excitation, along with broadband operation and low insertion loss. These characteristics position Te/PET films as a promising foundation for developing flexible terahertz functional devices. The researchers also examined mechanical stability by subjecting the device to repeated bending cycles and small bending radii; the transient terahertz photoresponse remained nearly unchanged, underscoring the mechanical tolerance of Te nanofilms and the flexibility of the PET substrate.
To explore its information-processing capability, the team integrated 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 of the device translates into reliable information processing. This suggests that flexible terahertz modulators could serve as front-end functional units for intelligent sensing and neuromorphic optoelectronic systems.
According to the scientists, "We introduce flexible Te/PET films as a mechanically robust platform for ultrafast all-optical terahertz modulation. The device exhibits broadband response, low insertion loss, high modulation efficiency, and picosecond photoresponse, while maintaining stable performance under bending deformation." They added that the stable response under mechanical states enables reliable neural-network-based image recognition, indicating potential for wearable optoelectronic systems. The results provide a new device strategy for flexible terahertz modulators and guidance for developing mechanically robust terahertz optoelectronic devices in complex deformation environments.
This study was supported by various funding sources, including the National Key R&D Program of China, the Postdoctoral Fellowship Program of CPSF, and the National Natural Science Foundation of China. For more information, visit the original source at https://doi.org/10.37188/lam.2026.086. The related link is http://chuanlink-innovations.com.
