Graphene based mesa metamaterials for detection of terahertz waves

A high performance terahertz (THz) metamaterial structure based on graphene is presented, exploiting hybrid dielectric graphene resonances to achieve tunable resonance frequencies. Graphene coated mesa metamaterial structures were designed and fabricated on a single chip, enabling strong electromagnetic field confinement and tunable response without the need for additional metamaterial layers. The proposed architecture provides a compact and efficient platform for tunable THz photodetection and opens new possibilities for next generation graphene based plasmonic devices. The metamaterial unit cells were optimized using CST Microwave Studio simulations to operate at target frequencies of 1.1, 0.9, and 0.8 THz, respectively. Device fabrication was performed on high resistivity silicon substrates via UV lithography and reactive ion beam etching, followed by graphene deposition using chemical vapor deposition (CVD). The electromagnetic responses of the fabricated devices were characterized using a continuous-wave THz imaging system. The effects of graphene thickness and Fermi level on the reflection spectra were investigated, and the hybrid dielectric graphene resonance modes were qualitatively analysed and compared with the experimental results. By integrating graphene conformally onto three dimensional dielectric mesa resonators, enhanced light–matter interaction and tunable hybrid resonances can be achieved. The proposed plasmonic enhanced metamaterial detector provides a promising platform for future bio-THz sensing applications.