Optical Limiting of Carbon Nanohorn-Based Aqueous Nanofluids: A Systematic Study
Authors: Sani E., Papi N., Mercatelli L., Barison S., Agresti F., Rossi S., Dell’Oro A.
Autors Affiliation: CNR-INO National Institute of Optics, Largo E. Fermi, 6, I-50125 Firenze, Italy; CNR-ICMATE Institute of Condensed Matter Chemistry and Technologies for Energy, Corso Stati Uniti, 4,I-35127 Padova, Italy; CNR-ITC Institute of Construction Technologies, Corso Stati Uniti, 4, I-35127 Padova, Italy; INAF, Astrophysical Observatory of Arcetri, Largo E. Fermi, 5, I-50125 Firenze, Italy;
Abstract: Nowadays, the use of lasers has become commonplace in everyday life, and laser protection has become an important field of scientific investigation, as well as a security issue. In this context, optical limiters are receiving increasing attention. This work focuses on the identification of the significant parameters affecting optical limiting properties of aqueous suspensions of pristine single-wall carbon nanohorns. The study is carried out on the spectral range, spanning from ultraviolet to near-infrared (355, 532 and 1064 nm). Optical nonlinear properties are systematically investigated as a function of nanohorn morphology, concentration, dimensions of aggregates, sample preparation procedure,
nanostructure oxidation and the presence and concentration of surfactants to identify the role of each parameter in the nonlinear optical behavior of colloids. The size and morphology of individualnanoparticles were identified to primarily determine optical limiting. A cluster size effect was also demonstrated, showing more effective optical limiting in larger aggregates. Most importantly, we describe an original approach to identify the dominant nonlinear mechanism. This method requires simple transmittance measurements and a fitting procedure. In our suspensions, nonlinearity was identified to be of electronic origin at a 532 nm wavelength, while at 355 nm, it was found in the generation of bubbles.
Volume: 10 (11) Pages from: 2160 to: 2160