Reinforced site isolation leading to remarkable thermal stability and high electrooptic activities in cross-linked nonlinear optical dendrimers

A series of cross-linkable electro-optic (E-O) dendrimers have been developed with anthracene- and acrylate-containing dendrons functionalized on the periphery of chromophores that can form thermally stable Diels-Alder adducts. These new E-O dendrimers with a high density of standardized AJL8-type chromophore are originally prone to thermo-decomposition in their thermoplastic form but can be converted into thermally stable networks to provide excellent site isolation for these chromophores. After poling, large E-O coefficients (up to 84 pm/V at 1310 nm) can be obtained in these dendrimers. These poled E-O dendrimers can maintain their alignment stability at 200 °C for 30 min and also possess impressive long-term stability at 150 °C for more than 200 h. This result provides a very effective molecular engineering approach to systematically increase the thermal stability of highly polarizable dipolar chromophores for high temperature on-chip applications.