Wavelength Dispersion of Optical Power Limiting in Stilbene3 Analyzed within a Three Level Model

Abstract

AbstractNonlinear transmission in a dye (stilbene3) exhibiting two-photon absorption (TPA) has been studied has a function of wavelength, in the visible range using nanosecond laser pulses. The results have been analyzed within a three level model: the first excited one is populated by TPA and is excited toward an upper level (excited state absorption, ESA). The TPA and ESA spectra obtained by optical limiting (δ∼10-46 cm4s photon-1molecule-1; δ∼ 10-16 cm2) are in good agreement with those determined by two-photon fluorescence and Kerr ellipsometry. Thus, nonlinear transmission appears as a useful technique to estimate the TPA and ESA contributions in optical limiting.