In this novel scheme, we have theoretically analysed the impact of characteristic parameters on THz radiation generation by propagating two collinear laser beams of slightly different frequencies ( \(\:{{\upomega\:}}_{1},{{\upomega\:}}_{2}\) ) in the array of quasi metallic carbon nanotubes (QMCNTs) based plasma. The laser beams interact with quasi-metallic carbon nanotubes and ionise the atoms of quasi-metallic nanotubes. Electrons of QMCNTs absorb the photon energy of laser beams and experience nonlinear ponderomotive force, thus producing a nonlinear current at the beat frequency. The nonlinear current density of plasma electrons of QMCNTs acts as a source for terahertz generation at the beat frequency. Normalised terahertz power multiplies extensively with the increased length and width of nanotubes. As the electron density of plasma of quasi-metallic nanotubes approaches plasma resonance i.e., at \(\:\:{\omega\:}_{\text{P}}\sim2.2\:\omega\:,\) oscillatory electrons of nanotubes-based plasma produce resonantly enhanced terahertz power. Change in length and width of QMCNTs significantly broadens the resonance peaks of terahertz power. For typical values of parameters, the resulting energy conversion efficiency is \(\:\sim{10}^{-4}\) and this can be used for imaging and security scanning for non-destructive testing.
