resonant enhancement of thz radiation through vertically aligned carbon nanotubes array by applying wiggler magnetic field

The present analysis develops a novel theory of terahertz radiation generation by beating of two laser beams, incident obliquely on the array of vertically aligned carbon nanotubes (cnts) in the presence of an external wiggler magnetic field. the array of cnts behaves as nanoantenna to generate thz radiations. the incident lasers exert a ponderomotive force on the electrons of the cnts to produce nonlinear oscillatory velocity, which beats with the applied wiggler magnetic field. this beating produces a nonlinear current at (ω2 − ω1, k2 − k1 + k0) which acts as an antenna to produce the thz radiation. we observe that when the beat frequency (ω2 − ω1) lies near the effective plasmon frequency of the cnts, strong thz radiation is produced due to a resonant interaction of the laser with cnt electrons. the externally applied wiggler magnetic field enhances the efficiency of thz radiation of nanoantenna by providing the necessary momentum to the generated thz radiation. we explore the impact of radius and length of nanotubes on the efficiency of thz generation. the generated thz power is enhanced at an optimum angle of incidence of lasers with an array of cnts.