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Ultra-broadband actively tunable terahertz modulator based on multi-stacked metamaterial
Bhagwat Singh Chouhan1, Sirsendu Ghosal1, K M Rohith1
1Department of Physics, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
Scientific Reports
|July 2, 2025
Summary
Researchers developed a flexible terahertz amplitude modulator using vanadium dioxide. This device achieves ultra-broadband modulation, paving the way for advanced wireless communication systems.
Area of Science:
- Photonics
- Materials Science
- Electrical Engineering
Background:
- Metasurfaces utilizing phase transition materials are crucial for terahertz photonic components.
- Vanadium dioxide (VO2) exhibits a temperature-dependent metal-insulator phase transition, enabling tunable optical properties.
Purpose of the Study:
- To introduce an ultra-broadband terahertz amplitude modulator based on the phase transition of VO2.
- To demonstrate a flexible and actively tunable terahertz modulator for future wireless communication systems.
Main Methods:
- Fabrication of a multi-stacked metamaterial (MM) on a flexible substrate.
- Transferring the flexible MM onto a VO2 thin film grown on a quartz substrate.
- Utilizing terahertz time-domain spectroscopy to characterize the modulation performance.
Main Results:
- Achieved an ultra-broadband full width at half maximum (FWHM) of 1.02 THz.
- Demonstrated a high modulation depth of 55% by varying temperature from 50 to 90 °C.
- Validated experimental results with a proposed transmission line model.
Conclusions:
- The developed flexible, tunable terahertz modulator utilizes a facile polyimide-mediated peel-off technique.
- This work enables versatile, flexible, and tunable terahertz photonic components for 6G and beyond applications.
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