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Title | Ultrathin tunable terahertz absorber based on MEMS-driven metamaterial. |
Publication Type | Journal Article |
Year of Publication | 2017 |
Authors | M Liu, M Susli, D Silva, G Putrino, H Kala, S Fan, M Cole, L Faraone, VP Wallace, WJ Padilla, DA Powell,, and M Martyniuk |
Journal | Microsystems & nanoengineering |
Volume | 3 |
Start Page | 17033 |
Date Published | 01/2017 |
Abstract | The realization of high-performance tunable absorbers for terahertz frequencies is crucial for advancing applications such as single-pixel imaging and spectroscopy. Based on the strong position sensitivity of metamaterials' electromagnetic response, we combine meta-atoms that support strongly localized modes with suspended flat membranes that can be driven electrostatically. This design maximizes the tunability range for small mechanical displacements of the membranes. We employ a micro-electro-mechanical system technology and successfully fabricate the devices. Our prototype devices are among the best-performing tunable THz absorbers demonstrated to date, with an ultrathin device thickness (~1/50 of the working wavelength), absorption varying between 60% and 80% in the initial state when the membranes remain suspended, and fast switching speed (~27 μs). The absorption is tuned by an applied voltage, with the most marked results achieved when the structure reaches the snap-down state. In this case, the resonance shifts by >200% of the linewidth (14% of the initial resonance frequency), and the absolute absorption modulation measured at the initial resonance can reach 65%. The demonstrated approach can be further optimized and extended to benefit numerous applications in THz technology. |
DOI | 10.1038/micronano.2017.33 |
Short Title | Microsystems & nanoengineering |