Highly photostabilized electro-optic polymer for next-generation high-speed optical modulator

We present highly photostabilized electro-optic (EO) polymers designed for next-generation optical modulators. Achieving high photostability requires shifting the maximum absorption wavelength (λmax) of EO dyes to shorter wavelengths to minimize absorption of telecommunication light, but this often reduces the molecular hyperpolarizability (β0), leading to lower electro-optic performance. Using quantum chemical calculations, we designed and synthesized two novel EO dyes (IDE01 and IDE02) that balance low optical absorption and high hyperpolarizability. As a reference, NEO823—a dye known for high electro-optic activity—was used. The calculated β0 values of IDE01 (591 × 10-30 esu) and IDE02 (865 × 10-30 esu) are comparable to NEO823 (863 × 10-30 esu), while their absorption at the telecommunication wavelength of 1310nm is much lower. EO polymer films were prepared using carbonate-based host polymers and exhibited significantly improved photostability under 85 °C air exposure and 1310nm irradiation. These results provide valuable insights into material design strategies for overcoming reliability challenges and advancing the practical implementation of EO polymers in high-speed optical communication systems.