Browsing by Subject "Terahertz radiation"

Now showing 1 - 2 of 2

Open Access
Broadband THz modulators based on multilayer graphene on PVC
(IEEE, 2016) Kaya, E.; Kakenov, Nurbek; Kocabaş, Coşkun; Altan, H.; Esentürk, O.
In this study we present the direct terahertz time-domain spectroscopic measurement of CVD-grown multilayer graphene (MLG) on PVC substrate with an electrically tunable Fermi level. In a configuration consisting MLG and injected organic dopant, the transmitted intensity loss of terahertz radiation was observed with an applied voltage between 0 and 3.5 V. We showed that MLG on PVC devices provided approximately 100 % modulation between 0.2 and 1.5 THz at preferentially low operation voltage of ca. 3V. The observed modulation bandwidth in terahertz frequencies appears to be instrument limited.
Open Access
Design of metamaterial-based nanostructures for 5G applications & thermal radiation management
(2023-06) Boşdurmaz, Ekin Bircan;
The properties of natural materials can be the only limiting factor in today’s technologies. For this, researchers in the last decades found that engineering the features of naturally occurring materials in the subwavelength scales can drasti-cally change their properties. These materials beyond the natural ones are called “metamaterials”, where “meta” means “beyond” in Greek. Although the fabrica-tion of these materials can be quite challenging, clever designs and exploitation of physical phenomena can lead to tunable responses, eliminating the need for multi-ple structures. Here, diﬀerent strategies for designing tunable meta-surfaces for a wide range of applications will be presented by giving two examples. These appli-cations are namely: 1. Graphene-based Metasurface Absorber for the Active and Broadband Manipulation of Terahertz Radiation, 2. Adaptive Thermally Tunable Radiative Cooling with Angle Insensitivity Using Phase-Change Material-Based Metasurface.