Broadband Optical Limiting of Single-Walled Carbon Nanotubes with Tetracarboxy-Substituted Phthalocyanine Ligand Composite

The broadband optical limiting of single-walled carbon nanotubes (SWCNTs) with tetracarboxy-substituted phthalocyanine ligand composite was assessed. For this purpose, optical studies of the spectra and nonlinear response were carried out. The value of the normalized transmittance in experiments on optical limiting, provided with the method of a fixed absorber arrangement, has been evaluated. The description of the nonlinear change in the transmitted energy fluence was carried out using the radiative transfer equation (RTE) for the case of a threshold dependence of the absorption coefficient on intensity. The determination of the nonlinear absorption coefficient and the threshold total pulse energy was performed on the optical limiting measurement data for a pulse. Knowing these parameters, the attenuation of the pulse was simulated by two methods: Z-scan with an open aperture and when the absorber was immovable at the focus of the lens.