Abstract
A simple model based on an effective‐mass approximation is developed to describe the dispersion behavior of the linear optical susceptibility χCitation1 of an array of aligned, identical single‐walled boron nitride nanotubes (BNNTs) in the spectral range where interband π‐electron transitions dominate. An analytic closed‐form expression for χ(1) valid in the low‐frequency part of the spectrum is obtained in terms of the band gap Δ g of BNNTs and the π‐electron transfer integral V ppπ. To the best of our knowledge, the present analytic calculation is the first for such nanotubes.