title: Reverse saturable absorption and anti-Stokes fluorescence in mesoionic compounds pumped at 532 nm.
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.
authors: Universidade Federal de Pernambuco, 50 670-901 Recife, PE, Brazil.
authors: N
authors: N
authors: Rakov
authors: C B
authors: CB
authors: de Araújo
authors: G B
authors: GB
authors: Rocha
authors: A M
authors: AM
authors: Simas
authors: P A
authors: PA
authors: Athayde-Filho
authors: J
authors: J
authors: Miller