Chromophores for Electro-Optics and Optical Switching

摘要

Two-photon absorption spectra have been measured for bis-donor diphenylpolyene derivatives with varying conjugation lengths and end groups. Large two-photon absorptivities are observed via nanosecond nonlinear transmission measurements in comparison to picosecond nonlinear transmission and two-photon excited fluorescence methods, which suggests a large contribution of excited-state absorption to the nanosecond nonlinear transmission results. Chromophores with conformationally locked bridges have been synthesized and the optical nonlinearity and thermal stability has been examined. It was found that relative to the normal polyene bridges, chromophores with confirmationally locked bridges exhibit improved thermal stability without a significant change in optical nonlinearity. A series of chromophores containing diarylamino donors have been synthesized and exhibit large optical nonlinearities, good thermal- thermal stabilities and enhance photochemical stabilities relative to compounds with dialkylamino donors. Functionalized versions of these chromophores have been synthesized for covalent incorporation into high performance polymers, for electro-optic applications.