ORGANIC MATERIALS FOR OPTICAL SECOND HARMONIC GENERATION.

The paper first presents a short description of the physical origin of nonlinear effects such as second harmonic generation (SHG), presents some of the typical organic nonlinear materials which have appeared in the literature, and then examines some of the important theoretical developments which attempt to relate SHG activity with molecular and crystal structure. Finally, the paper presents work on materials discovered in the authors' own laboratory and the rationale which went into their design and preparation.