Synthesis and characterization of a novel nonlinear optical hyperbranched polymer containing a highly performing chromophore

We report herein the peripheral functionalization of a high glass transition temperature hyperbranched polyimide with a new and highly performing electro-optic chromophore for the elaboration of a second-order nonlinear optical material. In this study, the CPO1 chromophore was selected for its very high quadratic hyperpolarizability coefficient (μβ = 31,000 ⋅ 10⁻⁴⁸ esu at 1990 nm) and its ease of synthesis in multigram scale. As a result, the new electro-optic polymer was characterized by an r₃₃ coefficient around 40 pm/V at 1.5 µm, although the poling conditions were not optimized. For sake of comparison, the electro-optic r₃₃ coefficient of our previously reported similar polymer functionalized with the well-known Disperse Red One chromophore was also measured using the technique and gave a much lower r₃₃ coefficient. This study underscores that hyperbranched polymers are particularly promising matrices to host highly efficient chromophore to achieve more efficient and more stable electro-optic devices than classical linear polymers. Copyright © 2013 John Wiley & Sons, Ltd.