Excited-State Absorption (ESA), Two-Photon Absorption (TPA) and the th
ird-order polarizability gamma(omega; omega, omega, - omega) have been
investigated for a model dichloride derivative of a symmetrically sub
stituted benzylidene analine (SBAC), using a multielectron configurati
on-interaction procedure. The calculations indicate that SBAC exhibits
ESA across the visible region of the spectrum, but that it is not as
extensive as for molecules such as the phthalocyanines. The magnitude
of the third-order polarizability is dominated by resonance enhancemen
t from a very strong A(g) --> B-u one-photon absorption. The calculate
d off-resonance value for gamma(omega; omega, omega, - omega) suggests
that SBAC is a potential candidate for ultrafast switching applicatio
ns.