The concept of the terahertz generator based on an array of double-walled carbon nanotubes with a direct current pump

A technique enabling the generation of THz radiation using an ordered array of double-walled carbon nanotubes (DWCNTs) pumped by a direct electric current is proposed. The initial excitation of surface plasmon polaritons (SPPs) in the DWCNTs is performed by two laser beams with slightly different frequencies. The amplification of exited slow SPPs (with a phase velocity down to ~10⁶ m/s) is provided by a drift current flowing through the DWCNTs. The DWCNTs with SPPs act as sources of THz radiation and emit coherent electromagnetic waves into free space. The proposed model of a carbon nanotube generator may be useful for the development of compact sources of coherent THz radiation.