Dispersion studies of optical nonlinearity and excited state dynamics in cyclo [4] naphthobipyrroles

Herein we present results from the dispersion studies of nonlinear optical (NLO) properties of three novel cyclo[4]naphthobipyrroles at wavelengths of 600 nm, 640 nm, 680 nm, and 800 nm using picosecond (ps) pulses. NLO coefficients were extracted from Z-scan measurements using similar to 1.5 ps pulses. Large two-photon absorption cross sections in the range of 0.2-5.2 x 10(4) GM and n(2) values of similar to 10(-16) cm(2)/W were recorded for these moieties. The excited state decay dynamics were investigated using degenerate pump-probe experiments with similar to 70 femtosecond pulses near 600 nm. Double exponential fits of the pump-probe data suggested two decay times for all the molecules investigated. (C) 2013 Elsevier B.V. All rights reserved.