Reverse saturable absorption and anti-Stokes fluorescence in mesoionic compounds pumped at 532 nm

N Rakov; C B de Araújo; G B Rocha; A M Simas; P A Athayde-Filho; J Miller

doi:10.1364/ao.40.001389

Reverse saturable absorption and anti-Stokes fluorescence in mesoionic compounds pumped at 532 nm

Appl Opt. 2001 Mar 20;40(9):1389-95. doi: 10.1364/ao.40.001389.

Authors

N Rakov¹, C B de Araújo, G B Rocha, A M Simas, P A Athayde-Filho, J Miller

Affiliation

¹ Universidade Federal de Pernambuco, 50 670-901 Recife, PE, Brazil.

PMID: 18357127
DOI: 10.1364/ao.40.001389

Abstract

Reverse saturable absorption and fluorescence in liquid solutions of mesoionic compounds are reported. Intensity-dependent transmittance and anti-Stokes fluorescence were observed when the samples were excited with radiation at 532 nm. The results are attributed to excited-state absorption, and the process is understood based on quantum-chemistry calculations that allow the energy levels that correspond to the relevant transitions to be located. A phenomenological description of the nonlinear beam propagation inside the samples is presented, and the nonlinear absorption coefficient as well as the saturation intensity is determined.