A photo-functional electro-optic polyimide with excellent high-temperature stability

We herein report the preparation of a soluble polyimide from a photoreactive diamine and a phenolic diamine, to which electro-optic (EO) properties were imparted by the introduction of an EO chromophore (Disperse Red 1) into the phenolic group of the polyimide. Following poling at 1 MV/cm and 210 °C, the polyimide was irradiated with UV light (280–310 nm) to form a photo-crosslinking network. The EO coefficient of the polyimide-containing EO device was 27.7 p.m./V at 1.3 μm, and this value was maintained at ≥90%, even after annealing at 150 °C for 500 h. Our results indicated that the thermal and chemical stabilities of the EO polyamide were remarkably increased due to the photo-crosslinking reaction.