Study of the Photoconductive and Optical Limiting Processes in Organic Nanostructures

Abstract

Among other areas of application of materials doped with fullerenes or carbon nanotubes (CNTs), the special aspect is being made to investigate these nanostructures in the near and middle infrared. In the present paper, the infrared nonlinear transmission processes in fullerene- and nanotubes- containing organic systems based on polyimide, polyvinyl alcohol, prolinol, pyridine, and polyaniline have been considered. The thin films, gels, solution, and dispersed liquid crystal compounds have been studied at wavelengths of 805, 1047, 1080, 1315, and 2940 nm. Optical limiting properties and photoconductive peculiarities have been found. The possible limiting mechanisms have been discussed. It should be mentioned that the photoconductivity of nanostructure-doped systems varies in the range of 5–6 orders of magnitude. Additionally, the study with a microscope has been made. The quasi-photonic organic system has been obtained. Thus, the diffraction of a laser beam passing through this structure would be considered as one of the mechanisms to attenuate the laser beam.

Keywords:

• fullerenes
• laser-matter interaction
• nanotubes
• near and middle infrared spectral range
• optical limiting
• organic nanostructures
• photoconductivity

Acknowledgments

The authors thank Dr. V. I. Studeonov and Yu. E. Usanov (Vavilov State Optical Institute, St.-Petersburg, Russia), Dr. Yu. M. Voronin and Dr. V. G. Bespalov (State Institute of Fine Mechanics and Optics, St.-Petersburg, Russia), and Dr. A. k. Fillippov(≪Plasmas≫ Firm, St.-Petersburg, Russia) for their help in this study. This work was supported by Russian National Technology Basis Program (Project ≪Limiter≫) and RFBR grant No. 04-03-32249.