Transmission properties of van der Waals materials for terahertz time-domain spectroscopy applications

Abstract This work contains results from studying the electro-optical properties of bulk and few-layered Van der Waals materials including intercalated graphene, phosphorene, and tungsten disulfide thin films. Different production methods and substrates are considered. The objective of the research is to assess the relevance of application of these materials in terahertz (THz) time-domain spectroscopy (TDS). Therefore, the study is conducted in the visible, NIR (near-infrared) and THz frequency ranges as the most critically in need of research when searching for effective materials for TDS

Graphene-based optically tunable structure for terahertz polarization control

Abstract We present a theoretical model of optically tunable graphene-based structure for polarization characteristics control of transmitted terahertz (THz) wave. The experimental verification was performed using a THz time-domain polarimetry setup. The tunability is achieved by applying an external optical pumping and magnetic field. The structure shows the possibility for dynamical control of ellipticity and azimuth angles of polarization state of THz radiation in a transmission mode. This study indicates a strong potential for using graphene-based structures for polarization sensitive applications such as THz wireless communications and biomedical research

Multi-layered graphene based optically tunable terahertz absorber

Abstract We present a broadband tunable terahertz (THz) absorber, which consists of cross-shaped multi-layered graphene (MLG) resonators. The proposed absorber possesses almost perfect absorption over the range 0.4—0.8 THz and can be easily fabricated. Dynamical tuning of absorption band is achieved by external optical pumping of modest intensity. This multi-layered graphene-based absorber has high potential for various THz applications

Terahertz time-domain polarimetry of carbon nanomaterials

Abstract Terahertz time-domain spectroscopic polarimetry (THz-TDSP) method was used to study of polarization properties of a few-layer graphene (FLG) and a randomly oriented single-walled carbon nanotube (SWCNT) thin film on silicon (Si) substrates in terahertz (THz) frequency range under an external optical pumping (OP) and an external static magnetic field (MF). Frequency dependencies of azimuth and ellipticity angles of a polarization ellipse of the samples were obtained experimentally. The results confirm the fact that, based on carbon nanomaterials, it is possible to devise tunable THz polarization modulators for use in the latest security and telecommunication systems