Flexible Te/PET films boost ultrafast terahertz modulation

Researchers in China developed flexible tellurium-on-PET films that act as all-optical terahertz modulators with picosecond response, low insertion loss and strong bending tolerance. The work points to flexible terahertz hardware that can hold up in wearable photonics, sensing and AI-enabled imaging systems.

Why it matters: - Flexible terahertz devices could enable wearable photonics, intelligent communication, flexible imaging and sensing systems. - Mechanical deformation in flexible devices can disrupt terahertz signals and cause information loss. - A modulator that keeps working while bent could make terahertz systems more practical outside the lab.

What happened: - A research team led by Professor Qingli Zhou of Capital Normal University and Professor Chen Ge of the Institute of Physics, Chinese Academy of Sciences developed flexible Te/PET films for ultrafast all-optical terahertz modulation. - The paper was published in Light: Advanced Manufacturing. - The device uses tellurium nanofilms grown on polyethylene terephthalate, or PET, substrates. - The researchers reported a broadband response, low insertion loss, a 50% modulation depth and picosecond-scale photoresponse. - The device also showed an ultrasensitive response under low pump excitation. - The study is identified by DOI 10.37188/lam.2026.086.

The details: - Tellurium offers a helical chain structure, strong optical response, high carrier mobility and ambient stability. - Te nanofilms on flexible PET form a mechanically robust and optically active platform for terahertz modulation. - The transient terahertz photoresponse stayed nearly unchanged after repeated bending cycles. - The response also remained stable under a small bending radius. - The flexibility of PET and the mechanical tolerance of Te nanofilms helped preserve performance during deformation. - The team fed the measured terahertz modulation response into an artificial neural network for image recognition. - Recognition accuracy stayed stable under different bending conditions. - The researchers linked that result to potential use in front-end functional units for intelligent sensing and neuromorphic optoelectronic systems. - The study was supported by China-based funding from the National Key R&D Program of China, the Postdoctoral Fellowship Program of CPSF, the Beijing Natural Science Foundation, the China Postdoctoral Science Foundation, the Beijing Postdoctoral Science Foundation, the National Natural Science Foundation of China and the Youth Innovation Promotion Association of CAS.

Between the lines: - The main advance is not just better terahertz modulation. It is modulation that remains usable under mechanical stress. - Stable image recognition under bending suggests the device may do more than transmit signals. It may also support downstream computation and sensing. - That combination makes the platform more relevant for wearable and deformable electronics than a conventional static terahertz modulator.

What's next: - The researchers say the work offers a new device strategy for flexible terahertz modulators. - The next step is likely moving toward mechanically robust terahertz optoelectronic devices that can operate in complex deformation environments. - Te-based flexible terahertz hardware could become a candidate for intelligent sensing and wearable optoelectronic systems.

The bottom line: - Te/PET films combine fast terahertz switching with bending resilience, which could help flexible terahertz devices move closer to real-world use.