Effects of Solvent on the Optical Nonlinearities of Multi-Walled Carbon Nanotubes under the Picosecond Laser Pulses

Abstract

Based on Z-scan technique, the nonlinear absorption and refraction characteristics of multi-walled carbon nanotubes (MWNT) in chloroform , deionized water and isopropyl alcohol have been studied under the picosecond (ps) laser pulses, respectively. The experimental results show that the nonlinear absorption characteristics of the MWNT in chloroform, deionized water and isopropyl alcohol are all saturable absorption, and their nonlinear absorption coefficients are 1.83×10-11 m/W, 1.97×10-11 m/W, 2.31×10-11 m/W, respectively. The nonlinear refraction characteristics of the three solutions are all self-focusing, and the nonlinear refractive coefficients are 4.37×10-12 esu, 1.68×10-12 esu, 8.34×10-13 esu, respectively. The third-order nonlinear susceptibilities of the three solutions are 6.32×10-13 esu, 5.62×10-13 esu, 7.11×10-12 esu, respectively. The experimental results indicate that the nonlinear optical property of the MWNT isopropyl alcohol solution is the strongest, and the MWNT deionized water solutions is the weakest. The solvents have a big effects on the nonlinear optical properties of MWNT solutions.