Nonlinear absorption and harmonic generation of laser in an assembly of CNT's

Abstract

An analytical formalism is developed to study the nonlinear propagation of a high power laser through an array of parallel carbon nanotubes and generation of second and third harmonics. The array is mounted on a planar surface, and a laser propagates perpendicular to the lengths of the tubes. The nonlinearity arises through the electrostatic restoration force on the displaced electron cylinder with respect to the ion cylinder by the laser. The effect is resonantly enhanced near the surface plasmon resonance. For typical powers of the laser and areal density of nanotubes of radius 2 × 10-8 m, the attenuation length turns out to be 5 cm. The second harmonic conversion efficiency is of the order of 1.4 × 10-2, while the third harmonic conversion efficiency is 0.9 × 10-2.