Orientational confinement of NLO molecules, both for a maximum EO effect and as a low barrier to photo-induced charge generation and transport, is considered a key principle in the design of potentially efficient organic photorefractive crystals. A supramolecular approach to space-charge induced photorefractive effects is discussed, on the basis of an inclusion lattice formed by perhydrotriphenylene (PHTP) and optically non-linear guest molecules exhibiting pronounced terminal functional group interactions along polar molecular strings.An increasing number of inorganic1 and organic2 materials are known to change their index of refraction under illumination; this effect is called photorefraction3 . Among the different photo-physical or photo-chemical mechanisms which lead to a change in the index of refraction, space-charge induced photorefractive (SCPR) effects show a complete reversibility, a wide range of response times and a high diffraction efficiency for low power CW writing beams. In contrast to materials showing photodiffractive3 phenomena, the SCPR effect occurs only for materials that both are electro-optic (EO) and show a lightinduced transport of charge carriers (e.g. photoconduction).Materials demonstrating space-charge induced dynamic gratings have been proposed for a number of real world applications, including high-density optical data storage, optical image processing and others4. However, difficulties related to the fabrication or some of the properties of known inorganic and organic photorefractive materials have thus far prevented technical application. Whilst photorefraction in oxides was discovered more than SP!E Vol. 2850 /55 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/21/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx

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1996 inclusion compounds inclusion compounds O 0400 46 -073 Crystallization of Supramolecular Materials: Perhydrotriphenylene ( PHTP) Inclusion Compounds with Nonlinear Optical Properties. -A linear arrangement of guest molecules (20 examples), e.g. (I)-(V), in PHTP inclusion compounds can lead to supramolecular materials with optimized physical properties. Through cocrystallization, different guests displaying pronounced nonlinear optical properties are incorporated within the channels of the host species to give a high yield of polar single crystals. -(HOSS, R.; KOENIG, O.; KRAMER-HOSS, V.; BERGER, U.; ROGIN, P.; HULLIGER,