Abstract

Seven chromophores with different dipole moments and polarizability anisotropies were synthesized by varying conjugation bridges, such as polyene, thiophene, indole, and benzene combined with strong electron-donor and electron-acceptor groups. The birefringence of photorefractive materials containing 30 wt% of chromophore was observed to be in the range of 0.45 × 10⁻³ to 5.0 × 10⁻³ at an electric field of 70 V µm⁻¹, depending on the chromophore structure. The photorefractive material containing a polyene-based chromophore exhibited the highest photorefractive property, followed by those containing thiophene-based, benzene-based and indole-based chromophores. It was observed that, within material systems used in this study, photorefractive properties of guest–host systems were linearly proportional to the orientational birefringence.