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