Efficient THz Generation by Nonlinear Interaction of Gaussian Laser Beam With the Anharmonic and Rippled CNTs Aligned Vertically in the Array

Abstract

We purpose a theoretical analysis for the generation of efficient terahertz (THz) radiation by using the nonlinear interaction of Gaussian laser beam with vertically aligned anharmonic, and rippled carbon nanotubes (CNTs) array. This array of vertically aligned carbon nanotubes (VA-CNTs) is embedded on the base of the dielectric surface. The VA-CNTs have been magnetized by applying a static magnetic field mutually perpendicular to the direction of propagation of the Gaussian beam and length of CNTs. The Gaussian laser beam passing through the CNTs exerts a nonlinear ponderomotive force on the electrons of CNTs and provides them resonant nonlinear transverse velocity. This produces the nonlinear current which is further responsible for the generation of THz radiation. The anharmonicity plays a vital role in the efficient generation of THz radiation. The anharmonicity arises due to the nonlinear variation of restoration force on the various electrons of CNTs. This anharmonicity in the electrons of CNTs helps in broadening the resonance peak. We have observed that externally applied static magnetic field 110 kg to 330 kg) also paves the way for the enhancement of the normalized THz amplitude.