ASSESSMENT OF OPTICALLY NONLINEAR ORGANIC-CRYSTALS

The information required from optical assessment of nonlinear organic materials differs widely depending on the application envisaged for th e material in question. Accordingly, a suitable assessment scheme must be devised which will give a reliable indication of the promise of th ese materials in a wide variety of applications. Such a scheme is desc ribed, beginning with the assessment of microcrystalline powders and e nding with predictions ot wavelength and angle criticality of phase ma tching in single crystals. Electro-optical assessment at low frequenci es is also described. It is shown that the performance of a material c annot be reliably expressed by any single parameter, but that it must be examined afresh for each application considered. Although several e xamples are discussed, the literature contains very few comprehensive nonlinear optical assessments. Based on the available data, some tenta tive structure-property relationships are proposed.