Sub-wavelength metamaterial structures are of great fundamental and practical interest because of their ability to manipulate the propagation of electromagnetic waves. We review here our recent work on the design, simulation, implementation and equivalent circuit modeling of metamaterial devices operating at Terahertz frequencies. THz metamaterials exhibiting plasmon-induced transparency are realized through the hybridization of double split ring resonators on either silicon or flexible polymer substrates and exhibiting slow light properties. THz metamaterials perfect absorbers and stereometamaterials are realized with multifunctional specifications such as broadband absorbing, switching, and incident light polarization selectivity.
Devices operating at THz frequencies have been continuously expanded in many areas of application and major research
field, which requires materials with suitable electromagnetic responses at THz frequency ranges. Unlike most naturally
occurring materials, novel THz metamaterials have proven to be well suited for use in various devices due to narrow and
tunable operating ranges. In this work, we present the results of two THz metamaterial absorber structures aiming two
important device aspects; polarization sensitivity and broad band absorption. The absorbers were simulated by finite
element method and fabricated through the combination of standard lift-off photolithography and electron beam metal
deposition. The fabricated devices were characterized by reflection mode THz time domain spectroscopy. The narrow
band absorber structures exhibit up to 95% absorption with a bandwidth of 0.1 THz to 0.15 THz.
Among electromagnetic spectrum, terahertz region has been utilized less due to the lack of appropriate devices that works well in these frequencies But recently growing interest has been focused to design devices with functionality in terahertz region because of potential terahertz applications. We present a novel structure that broadens bandwidth of terahertz metamaterial absorber. Our structure takes a benefit of multiband absorber by making the bands close enough to each other but in a multilayer pattern. The absorber has composed of two concentric copper rings in two different layers followed by polyimide and a metal back layer. Simulation shows 100 GHz bandwidth which is double of that of a single layer single ring absorber.