Open AccessMechanically Tunable Terahertz Metamaterial Perfect Absorber
Author(s) -
Piper Lewis K.,
Singh H. Johnson,
Woods Jonathan R. C.,
Sun Kai,
Muskens Otto L.,
Apostolopoulos Vasilis
Publication year - 2021
Publication title -
advanced photonics research
Language(s) - English
Resource type - Journals
ISSN - 2699-9293
DOI - 10.1002/adpr.202100136
Subject(s) - terahertz radiation , metamaterial , resonator , optics , absorption (acoustics) , split ring resonator , reflection (computer programming) , materials science , optoelectronics , metamaterial absorber , range (aeronautics) , extinction ratio , interferometry , resonance (particle physics) , physics , tunable metamaterials , computer science , wavelength , composite material , programming language , particle physics
The development of a wide range of technologies based on terahertz (THz) electromagnetic radiation drives a strong demand for flexible optical elements. Metasurfaces based on metallic resonators offer a versatile toolkit that permits easy tuning over a wide spectral range by the geometric design. Herein, a mechanically tuned metasurface perfect absorber comprised of split‐ring resonators in combination with a metallic mirror in a microcavity arrangement, is demonstrated. By mechanically tuning the length of the microcavity in the range of 10 μm and above, precise control over the perfect absorption condition is exhibited. A maximum recorded extinction of 45.8 dB is obtained at the perfect absorption condition, corresponding to a suppression of the reflected radiation by almost five orders of magnitude. Experiments are performed in a reflection arrangement using a terahertz time‐domain spectrometer. Simulations of the experimental arrangement show that near‐field effects are weak and the enhancement of metamaterial perfect absorption is in agreement with purely interferometric effects.