Direct laser fabrication of five-band symmetric terahertz metamaterial with Fano resonance

Textured metallic surfaces such as metamaterial provide an increased plasmonic activity which result in localized field enhancement in terahertz frequency range. A simple and novel planar multi-band THz metamaterial with closely spaced band resonance for sensing application is presented. Numerical simulation of the designed structure was done using CST Microwave studio software. A rapid direct writing process using ultrafast laser was adopted for fabricating the proposed multi-band MM structure. The proposed structure displayed band stop characteristics at five frequencies 0.51 THz, 0.56 THz, 0.69 THz, 0.7 THz and 0.79 THz respectively with a loss exceeding 50 dB. A sharp Fano resonance was observed at 0.66 THz frequency from the constructive interference between the resonators. The terahertz transmission characteristic of the fabricated structure was done using THz-TDS technique.