Photochemical nonlinear optical effects

The coplanarity has endowed arylated TEEs with some of the highest known third-order optical nonlinearities and, in the case of acentricity, also very large second-order nonlinear optical effects. Furthermore, the strain-free planarity allows cis- and trans-arylated TEEs to interconvert upon photochemical excitation without competition from undesirable thermal isomerization. 

In the last few years sol-gel glasses have been applied in many novel inventions (2, 26) such as tunable solid-state lasers (containing photochemical resistant organic colorants with very high luminescence yields (27, 28)) nonlinear optical effects due to... 

Nanometer sized semiconductor dusters, expected to have properties different from those of molecular and bulk semiconductors of the same composition, represent a new class of materials. Interest in their preparation and potential applications as photocatalysts and device components used in quantum electronics and nonlinear optics is growing rapidly. Isolated, so-called nanophase semiconductors can be considered as zero and one dimensional quantum dots and quantum wires. Their electronic, optical, and photochemical properties change with cluster size. Wider electronic band gaps and new absorption maxima in the electronic spectra have been observed as the size of these materials decreases and have been interpreted as quantum size effects. For example, as the dimensions of the semiconductor particle are reduced, a shift to higher energy in the absorption spectrum relative to that of the bulk is generally observed. 

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