Autor(es)

Moyses, Renato Mafra ; Barbano, Emerson Cristiano ; da Silva, Daniel Luiz ; Vivas, Marcelo Goncalves ; Misoguti, Lino

• Tipo de documento: Artigo Científico
• Fonte: Physical Chemistry Chemical Physics; v. N/A, p. 10-pg., 2023-01-19.

Resumo

Azochromophores present interesting optical properties for application in all-optical switches (AOSs), such as ultrafast photoisomerization and considerable nonlinear optical response. However, determining the frequency-resolved microscopic second-order hyperpolarizability (real and imaginary parts) related to the pure electronic effects of molecules in solution is a challenging task. In this context, we have used femtosecond-laser induced nonlinear ellipse rotation (NER) measurements to obtain the electronic nonlinear refraction (n(2)(omega)) and two-photon absorption spectra (alpha(2PA)(omega)) of four azochromophores dissolved in methanol and acetone. The measurements ranging from similar to 600 up to similar to 1300 nm were performed in Disperse Red 1 (DR1), Disperse Red 13 (DR13), Disperse Red 19 (DR19), and Disperse Orange 3 (DO3). Because we carried the solution in a silica cuvette and used a short focal length, we were able to measure the solution's nonlinearities with high precision, as the silica from the cuvette walls worked as a suitable reference medium. Consequently, we precisely determined n(2)(omega), alpha(2PA)(omega), and the second-order hyperpolarizability (gamma(omega)) for all molecules and explained the different magnitudes based on the push-pull character. Furthermore, the solvation effect due to the change from methanol to acetone solvent on the n(2)(omega), alpha(2PA)(omega), and gamma(omega) is also reported. The results were elucidated using the sum-over-states (SOS) approach within the few-energy-level model and the results were obtained via quantum-chemical calculations using the cubic response function formalism within the density functional theory framework. Finally, we used these results to determine the frequency-resolved figure-of-merit for all-optical switching applications. Our results suggest that chromophores have the potential for applications in AOS based on Fabry-Perot filters. (AU)

• Processo FAPESP: 18/11283-7 - Fotônica não linear: espectroscopia e processamento avançado de materiais
• Beneficiário: Cleber Renato Mendonça
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 15/20032-0 - Estudo das Propriedades Ópticas Não Lineares e de Transporte de Carga de Moléculas Multiramificadas via Métodos de Química Quântica.
• Beneficiário: Daniel Luiz da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular