ASSESSMENT OF OPTICALLY NONLINEAR ORGANIC-CRYSTALS

The information required from optical assessment of nonlinear organic materials differs widely depending on the application envisaged for the material in question. Accordingly, a suitable assessment scheme must be devised which will give a reliable indication of the promise of these materials in a wide variety of applications. Such a scheme is described, beginning with the assessment of microcrystalline powders and ending with predictions ot wavelength and angle criticality of phase matching in single crystals. Electro-optical assessment at low frequencies is also described. It is shown that the performance of a material cannot be reliably expressed by any single parameter, but that it must be examined afresh for each application considered. Although several examples are discussed, the literature contains very few comprehensive nonlinear optical assessments. Based on the available data, some tentative structure-property relationships are proposed.