Highly efficient and stable bithiophene-based nonlinear optical chromophores for polymer electro-optic applications

摘要

The continuous interest in poled electro-optic polymers for device applications in information processing and telecommunications has resulted in the development of several types of second-order nonlinear optical chromophores that are highly efficient, as characterized by their large scalar product of dipole moment (μ) and the molecular first-order hyperpolarizability (β). It has been shown that incorporation of thiophene rings into the conjugated units can greatly enhance μβ while permitting a high thermal stability. According to the general guideline for optimization of μβ we reason that using bithiophene moieties, having a longer conjugation length than the monothiophene ones, should further increase μβ while maintaining the thermal, chemical, and photochemical stability.