Ultrafast Frequency Agile Optical Materials: Organically Doped Sol-Gel Glasses.

摘要

This report focuses on organically doped sol-gel glasses as novel fast response photochromic materials. In particular, we discuss time-resolved spectroscopic measurements of: (1) nanosecond optical energy transfer in organically doped glasses; (2) investigation of the spatial distribution of chromophores within the porous sol-gel matrix; (3) homogeneous dephasing of optically excited states as a probe of chromophore-host interactions; (4) time-resolved anisotropy measurements as a probe of chromophore dynamics in porous sol-gel matrices; and (5) optical limiting based on fast photophysical processes of organic chromophores. Optical energy transfer in organically doped sol-gel glasses is investigated by time-resolved fluorescence depolarization measurements. We observe nanosecond optical energy transfer and analyze these results in terms of the spatial distribution of chromophores in doped porous xerogel glasses. Time-resolved polarized emission results are also used to probe the rotational dynamics of chromophores during the fabrication process from solution to gel to porous glass. Further-more, picosecond photon echo measurements have been used to obtain the homogeneous dephasing rate of organic dopants in an inorganic sol-gel glass, as a means of probing chromophore-host environment.... Smart materials, Sol-gel glasses, Photochromic, Energy transfer.