Third-order nonlinear optical properties of colloidal Au nanorods systems: saturable and reverse-saturable absorption
| Autor: | Servando Almaguer-Valenzuela, Oswaldo Sanchez-Dena, Jorge-Alejandro Reyes-Esqueda, E. V. García-Ramírez, Oscar Baldovino-Pantaleón |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
business.industry Surface plasmon Nonlinear optics Saturable absorption 02 engineering and technology 021001 nanoscience & nanotechnology Laser 01 natural sciences Atomic and Molecular Physics and Optics Light scattering law.invention 010309 optics Wavelength Optics law 0103 physical sciences Nanorod 0210 nano-technology Absorption (electromagnetic radiation) business |
| Zdroj: | Optics express. 24(2) |
| ISSN: | 1094-4087 |
| Popis: | In this work, we present a study of the nonlinear absorption properties from different gold nanorod (NR) systems in aqueous suspension. The NRs were obtained with the bottom-up protocol by the seed-mediated growth method (SMG), using Ag(+) ions at different concentrations, and CTAB as surfactant. By using this method, aspect ratios between 2 and 5 were obtained. The transverse surface plasmons (TSP) are located between 514 - 535 nm, while the longitudinal surface plasmons (LSP) are between 639 - 921 nm, for the different samples studied. The Z-scan technique was implemented for open (OA) and closed (CA) aperture at 532 and 1064 nm, with laser pulses of 26 ps, for vertical and horizontal polarizations, with respect to the incidence plane (horizontal). At 532 nm all samples showed saturable absorption (SA), while for samples with LSP near 1064 nm, such effect was observed only at low-energy pulse experimental conditions. In the high-energy pulse regime, an apparent reverse-saturable absorption (RSA) was observed for both wavelengths. However for 532 nm, it was possible to determine that this effect results from structural changes in the samples, which are manifested through the behavior of nonlinear absorption and refraction curves. These results were used to determine the irradiances to which NRs can be modified by photodegradation. |
| Databáze: | OpenAIRE |
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