Self-diffraction and high nonlinear optical properties of carbon nanotubes under CW and pulsed laser illumination

Abstract

In this work, self-diffraction effect in carbon nanotubes (CNTs) that were dispersed on N,N-dimethylformamide (DMF) solvent is studied. Third-order nonlinear optical coefficients of this nano-suspension are measured using z-scan technique and high nonlinearity is observed. Nonlinear refraction index of the order −10−6cm2W is obtained due to the thermal effect and the nonlinear interaction of the light and the surface plasmonic electrons. Optical diffraction rings of the sample under He–Ne laser illumination at a wavelength of 632.8nm were observed and intensity distribution of the rings is explored. At last, optical limiting performance of CNTs is investigated under irradiation by a continuous wave (CW) He–Ne laser. The optical limiting behavior is investigated by using transmission measurement through the sample and our studies indicate that this material is a potential candidate for optical limiting applications in low power CW regime.