Absorption Cross-Section and Near-Field Enhancement in Finite-Length Carbon Nanotubes in the Terahertz-to-Optical Range

Electromagnetic characteristics of single-walled finite-length carbon nanotubes - absorption cross-section and field enhancement in the near zone - are theoretically studied in a wide frequency range from terahertz to visible. The analysis is based on the impedance-type effective boundary conditions and the integral equation technique. Comparison with experimental results is carried out allowing qualitative physical interpretation of low-frequency (far-IR and terahertz) absorption band observed in experiments. Potentiality of CNTs for the IR photothermolysis of living cells is discussed. Strong local field enhancement is predicted to be inherent to metallic CNTs in the near-field zone providing necessary mechanism for far-IR and terahertz near-field optics.