Organic superlattices measurements

To illustrate the potential of LB films in nonlinear optics, two examples will be given to illustrate both quadratic- and cubic-order effects. The motivation for the first example came from early accounts of nonlinearity in a specific merocyanine dye molecule (49). No good crystals of this material are available, but an extremely large value of P was predicted on the basis of measurements with powdered samples. The reliability of such data is not high because powder efiSciency is a function of particle size distributions. The initial experiments were with a simple merocyanine dye alternated with o)-TA. However, the best results (50) were obtained by using organic superlattices based on the two molecules shown by Structures 4. la and 4. lb. 

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