Carbon Nanotubes-Based Magneto-Optically Tunable Structure for Terahertz Wave Polarization Control

Terahertz time-domain spectroscopic polarimetry (THz-TDSP) method was used to study of polarization properties of a randomly oriented single-walled carbon nanotube (SWCNT) thin film on a high resistivity monocrystalline silicon (Si) substrate in terahertz (THz) frequency range under an external optical pumping and an external static magnetic field. Frequency dependencies of azimuth and ellipticity angles of a polarization ellipse and the polarization ellipse at various frequencies of the electromagnetic waves transmitted through the Si substrate and the SWCNT on the Si substrate were obtained experimentally based on the solution of the system of the Stokes parameters. The results of the study of this magneto-optically tunable structure confirm the fact that, based on the Faraday effect in the SWCNT, it is possible to devise efficient tunable THz polarization modulators for use in physics, chemistry, medicine, and the latest security and telecommunication systems.