Second-harmonic generation and linear electro-optical coefficients of BN nanotubes
Journal
Physical Review B - Condensed Matter and Materials Physics
Journal Volume
72
Journal Issue
7
Date Issued
2005
Author(s)
Lin, J.C.
Abstract
A systematic ab initio study of the second-order nonlinear optical properties of BN nanotubes within density functional theory in the local density approximation has been performed. Highly accurate full-potential projector augmented-wave method was used. Specifically, the second-harmonic generation (χabc(2)) and linear electro-optical (rabc) coefficients of a large number of the single-walled zigzag, armchair, and chiral BN nanotubes (BN-NT) as well as the double-walled zigzag (12,0)@(20,0) BN nanotube and the single-walled zigzag (12,0) BN-NT bundle have been calculated. Importantly, unlike carbon nanotubes, both the zigzag and chiral BN-NTs are found to exhibit large second-order nonlinear optical behavior with the χabc(2) and rabc coefficients being up to 30 times larger than that of bulk BN in both zinc-blende and wurtzite structures, indicating that BN-NTs are promising materials for nonlinear optical and optoelectric applications. Though the interwall interaction in the double-walled BN-NTs is found to reduce the second-order nonlinear optical coefficients significantly, the interwall interaction in the single-walled BN-NT bundle has essentially no effect on the nonlinear optical properties. The prominant features in the spectra of χabc(2)(-2ω,ω,ω) of the BN-NTs are successfully correlated with the features in the linear optical dielectric function ε(ω) in terms of single-photon and two-photon resonances. © 2005 The American Physical Society.
Type
journal article