We report on the synthesis and characterization of a novel series of hetero
cycle-based chromophores for third order non-linear optics (NLO), showing e
nhanced two-photon absorption activity and frequency-upconverted lasing eff
iciency. The parent compound is a push-pull system where a pyridinium ion a
cts as acceptor group and N-methylpyrrole as a donor. Its efficiency in the
two-photon-pumped lasing conversion from 800 to 543 nm is one of the highe
st ever reported. We show here the role of the position and nature of subst
ituents in the tuning and optimization of the lasing wavelength and convers
ion efficiency.