Abstract
In this work, we report on second order nonlinear optical (NLO) susceptibilities of some substituted 4-(5-nitro-1,3-benzoxazol-2-yl)aniline chromophores that were embedded into photopolymer matrices. Depending on the photo-induced nitrogen laser (wavelength 371 nm) power density of photo-solidification we found an optimal photo-solidification parameter to achieve maximum second harmonic generation (SHG). The influence of the π-conjugated bonds on the output second order susceptibility and HOMO-LUMO level positions is analysed. The performed experiments are compared with the theoretically calculated microscopic hyper-polarizabilities obtained within the B3LYP DFT approach. The possible operation by the output SHG efficiency versus the photoinduced laser power density is presented. The role of the intra-molecular and surrounding polymers in the observed nonlinear optical behaviour is explored.
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•Second order nonlinear optical susceptibilities of organic chromophores/photopolymer matrices were studied.•Microscopic hyper-polarizabilities were obtained within the B3LYP DFT approach.•SHG efficiency versus the photoinduced laser power density is presented.•DFT simulations confirm the donor–acceptor charge transfer in the observed output second-order efficiencies.•The effects are crucially dependent on the photo-illumination time.