The demand for flexible terahertz devices is surging, driven by applications in wearable photonics, intelligent communication, and flexible imaging. Yet, mechanical deformation often compromises performance, causing signal loss and interruptions. Addressing this, researchers have introduced tellurium (Te) nanofilms on polyethylene terephthalate (PET) substrates as a flexible platform for all-optical terahertz modulation, achieving high modulation efficiency and picosecond response while maintaining robustness under bending.
Published in Light: Advanced Manufacturing, the study led by Professor Qingli Zhou from Capital Normal University and Professor Chen Ge from the Institute of Physics, Chinese Academy of Sciences, demonstrates that Te/PET films can function as ultrafast all-optical terahertz modulators. These devices exhibit a modulation depth of 50% on a picosecond timescale, low insertion loss, and broadband operation. The unique helical chain structure of tellurium, coupled with its high carrier mobility and ambient stability, makes it an ideal candidate for flexible optoelectronic applications.
The researchers rigorously tested the mechanical stability of the Te/PET films under various bending conditions. They found that the transient terahertz photoresponse remained nearly unchanged after repeated bending cycles and even under small bending radii. This resilience is attributed to the mechanical tolerance of the Te nanofilms and the flexibility of the PET substrate, ensuring reliable modulation even when the device is deformed.
To demonstrate practical utility, the team integrated the measured terahertz modulation response into an artificial neural network (ANN) for image recognition tasks. Remarkably, the recognition accuracy remained stable across different bending states, indicating that the mechanical robustness translates into dependable information processing. This suggests that flexible terahertz modulators could serve as front-end units in intelligent sensing and neuromorphic optoelectronic systems.
The researchers summarized their findings: "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 further noted, "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."
This work provides a new device strategy for flexible terahertz modulators and offers guidance for developing mechanically robust terahertz optoelectronics capable of operating in complex deformation environments. The study was supported by several funding agencies, including the National Key R&D Program of China and the National Natural Science Foundation of China. For more details, refer to the original publication at https://doi.org/10.37188/lam.2026.086.
