Design and synthesis of bichromophores for nonlinear optical applications in polymer films

Three bichromophores were designed and synthesized by linking a vinylthiophene-conjugated chromophore with different tether groups via esterification. Second harmonic generation measurements of nonlinear polymer films revealed that the second harmonic generation coefficients of the films containing the bichromophore and using 3-phenoxypropane-1,2-diyl succinic diester as the tether group were improved in comparison with the mono-chromophore-doped polymer films. However, the second harmonic generation coefficients of the polymer films containing bichromophores using isophthalic ester as the tether group were decreased. Overall, the results indicate that the 3-phenoxypropane-1,2-diyl succinic diester tether group has potential applications in the design and synthesis of multi-chromophoric dendrimers with large macroscopic optical nonlinearity.