THEORY OF NONLINEAR-OPTICAL PROPERTIES OF C-60-DERIVED NANOTUBES

We study the third-order optical nonlinearities (characterized by the second-order hyperpolarizabilities gamma) of C-60-derived nanotubes. I t is found that the static gamma magnitudes of armchair (C60+ix10) and zigzag (C60+ix18) nanotubes obey their own exponent laws given by gam ma/gamma(60)=(1+ix10/60)(3.15) and gamma/gamma(60)=(1+ix18/60)(2.98), respectively, where gamma(60) is the static gamma magnitude of C-60 an d i is a positive integer. Also, the dynamical nonlinear optical respo nses of armchair and zigzag nanotubes are studied in detail. It is fou nd that the symmetry and caps of these nanotubes have a large effect o n their third-order optical nonlinearities. By these detailed studies, we find that armchair and zigzag nanotubes can compete with polymeric materials for photonic applications due to their large nonresonant an d resonant third-order optical nonlinearities. (C) 1998 American Insti tute of Physics.