Nonlinear optical enhancement effect of nickel-coated multi-walled carbon nanotubes

Abstract

In this letter, the nonlinear optical properties of nickel-coated multi-walled carbon nanotubes and multi-walled carbon nanotubes (MWCNTs) were investigated by Z-scan technique. The nonlinear absorption (NLA) of nickel-coated MWCNTs are significantly enhanced in comparison with that of MWCNTs under the excitation of 532 nm and 1064 nm laser pulse. After coating the nickel films on MWCNTs, the nonlinear refraction of the samples change from the initial self-defocusing to the self-focusing effect under the excitation of 1064 nm laser pulse. The sign of the nonlinear refractive indices remain unchanged at 532 nm. The excellent nonlinear performance of nickel-coated MWCNTs leads to a potential application in the photonic field.