Study On Nonlinear Optical Properties Of Carbon Nanotubes

In order to further study of third-order optical nonlinearity of multi-walled carbon nanotubes, we compound multi-walled carbon nanotubes synthesized aqueous solution,multi-walled carbon nanotubes chloroform solution and multi-walled carbon nanotubes isopropyl alcohol solution. But due to the strong van der Waals force between carbon nanotubes and make it easy to gather or bundle intertwined, seriously restricted the nonlinear effect of carbon nanotubes. Therefore, to study of third-order nonlinear optical properties of carbon nanotubes, the first we must study the decentralized approach, to this end, we used in experiment is dodecyl benzene sulfonic acid sodium,and through repeated measurements it is concluded that the best proportion is about1:10. In this paper, we mainly use Z scan technology and pump detection technology research of carbon nanotubes third-order optical nonlinear and dynamic process.Using picosecond Z scan technology to measure isopropyl pure energy of multi-walled carbon nanotubes solution, the results show that with the continuous increase of energy, the saturated absorption enhanced gradually, the nonlinear refraction of the valley value has been suppressed, gradually disappear and peak has been enhanced. at the same time, we also studied the different linear transmittance(s) of chloroform solution and the effect of multi-walled carbon nanotubes as the hours and peak valley difference, when it smaller, the result is more obvious, when it bigger, the lower the accuracy of measurement.Using femtosecond Z scan technology to measure different energy of multi-walled carbon nanotubes chloroform solution, the results found that already exist in the process of the experiment of saturated absorption and exist the saturated absorption, with the continuous increase of energy, the saturated absorption has been enhanced, this is due to the ground state electron resonance with the carrier to absorb the results of the competition.To test the correctness of the Z scan results, we use the 4f phase to test coherent imaging of samples, the experimental results show the present of all centered around the bright, the round are dark images, can be judged from the self-focusing, it exactlythe same as that of Z scan results.Finally, the paper also use the pump detection to measure chloroform solution of multi-walled carbon nanotubes and multi-walled carbon nanotubes, isopropyl alcohol solution with hydroxyl chloroform solution of multi-walled carbon nanotubes and multi-walled carbon nanotubes with hydroxyl into the ethanol solution, after repeated experiments, but the sample solution do not showe good ultrafast dynamics process.