<title>Structure-property relationships and development of new molecules and polymeric materials for nonlinear optics</title>

In order to design new organic NLO materials with both higher nonlinear optical susceptibilities, and reasonable optical loss characteristics, it is necessary to understand how different organic structural elements affect the nonlinearity of materials at the molecular level. Only recently, synthetic research groups have begun to devote the time and effort necessary to produce very pure model compounds of systematically varied structures for carefully controlled NLO measurements. In this presentation experimental results and the structural- NLO property trends developed from them are reviewed for the systematic investigations appearing in the literature with emphasis placed on studies conducted by our research group. With these results in mind, some new ways of looking at such organic molecular structures are presented with the intent of stimulating creative thought for novel NLO molecular design.