Heterocycle-based materials for frequency-upconverted lasing

We report on the synthesis and characterization of a novel series of heterocycle-based chromophores for third order non-linear optics (NLO), showing enhanced two-photon absorption activity and frequency-upconverted lasing efficiency. The parent compound is a push-pull system where a pyridinium ion acts 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 highest ever reported. We show here the role of the position and nature of substituents in the tuning and optimization of the lasing wavelength and conversion efficiency.