A tunable terahertz sensor based on a hollow hexagonal graphene metasurface

Li Yijia, Peng Yajing, Huang Yongjun, Zhang Jinshun, Guo Qing, Liu Yuhui

For Russian citation (Opticheskii Zhurnal):

For citation (Journal of Optical Technology):

Li Yi., Peng Ya., Huang Yo., Zhang J., Guo Q., Liu Yu. A tunable terahertz sensor based on a hollow hexagonal graphene metasurface (Перестраиваемый терагерцовый датчик на основе полой гексагональной графеновой метаповерхности) [на англ. яз.] // Оптический журнал. 2026. Т. 93. № 11. С. 30–42. http://doi.org/10.17586/1023-5086-2026-93-11-30-42

Li Yi., Peng Ya., Huang Yo., Zhang J., Guo Q., Liu Yu. A tunable terahertz sensor based on a hollow hexagonal graphene metasurface [in English] // Opticheskii Zhurnal. 2026. V. 93. № 11. P. 30–42. http://doi.org/10.17586/1023-5086-2026-93-11-30-42

Abstract:

Subject of the study. A tunable terahertz sensor based on a hollow hexagonal graphene metasurface is studied. The structure comprises a graphene metasurface, a silicon dioxide dielectric spacer, and Au reflective layer. Purpose of the work. Development of a dynamically tunable terahertz sensor with high absorptance and high refractive index sensitivity. Method. The sensing mechanism is based on the coupling between graphene surface plasmon polaritons and the hybrid resonance induced by the metallic layer. Structural optimization and performance evaluation are carried out using finite element simulations. Main results. A dual-mode perfect absorption is obtained at 1.33 and 5.17 THz with the absorptance of 99.9% and 99.8%, respectively. The high-frequency mode achieves a sensitivity of 1.5 THz per refractive index unit, a figure of merit of 2.73, and a quality factor of 8.85. By tuning the graphene Fermi energy, the high-frequency resonance mode exhibits a continuous tunable range from 4.80 to 6.28 THz with absorptance exceeding 99.2%. This dual-mode response enables precise multi-band sensing capabilities. Practical significance. The results offer a design strategy for high-performance terahertz sensing, with promising applications in biomolecular recognition and medical diagnosis.

Keywords:

terahertz metamaterial, graphene metasurface, tunable sensing, surface plasmon polaritons

Acknowledgements:

this paper is partly supported by the Open Project of Ocean Research Institute of Bohai University (№ BDHYYJY2025012) and the Department of Education Fund of Liaoning province (№ LJKMZ20221495).

OCIS codes: 280.4788, 160.3918, 240.6680, 300.6495

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