Study Of Terahertz Spectrum Reconfigurable MEMS Metamaterials

In recent years, terahertz technology develops fast. As a complete system, other than optical sources and detectors, terahertz devices to control the transmission and connection are needed. Therefore, various terahertz devices based on metamaterials have been a research hotspot. Realizing the configuration of metamaterial frequency spectrum and expanding the scope of application have been more and more important. The scale of MEMS happens to be identical with the sub wavelength of terahertz wave, so MEMS technologies are the best choice to fabricate metamaterials in micro and nano scale. What’s more, MEMS actuation can be used to change the geometric parameters of metamaterial periodic unit, in order to adjust the resonance frequency of metamaterials finally. In this paper, based on MEMS technologies, metamaterials whose resonance frequency is tunable and metamaterial absorbers are studied through theoretical analysis, simulation and fabrication.Firstly, a model of metamaterials whose resonance frequency is tunable is proposed, which is suitable for the MetalMUMPs process of MEMSCAP company and can be actuated by thermal actuation. The influence of unit structural parameters on resonance frequency is simulated by commercial software CST Microwave Studio. The model of MEMS thermal actuation is simulated by commercial software Comsol Multiphysics. The displacements under different applied currents are simulated. A metamaterial whose resonance frequency can be tuned from1.371THz to1.574THz is proposed finally.Based on the research of metamaterials whose resonance frequency is tunable, an absorber whose frequency spectrum is reconfigurable is modeled and simulated, which can be fabricated by surface micromachining sacrificial layer technologies. The absorption peak frequency of absorber can be tuned from0.87THz to0.96THz continuously. The peak of absorption is above96%through the whole tunable frequency range. The full width at half maximum absorbance is below4%.In order to test the THz metamaterials, metamaterial arrays and absorbers are fabricated on paralyne. THz-TDS experimental platform is adopted to test the performance of metamaterial devices. The resonant response on the resonance frequency is obvious. What’s more, lots of experience on fabrication process is gathered.