Optical power limiting properties of organic crystals and nanocrystals in an f/5 optical system

We have evaluated the optical limiting properties of transparent organic crystals and nanocrystals in an f/5 optical system. We have studied three organic or organic-inorganic crystals and a sol-gel glass which contains organic nanocrystals of stilbene3. The spectral dependence of the optical limiting curves have shown that broadband limitation can be achieved in the visible range with the 2-amino-5-nitropyridinium-dihydrogenphosphate (2A5NPDP) crystal as the transmitted energy is less than 10 mu J over a wide spectral range (450-600 nm). Results on nanocrystals have indicated that these new materials are a suitable alternative to crystals due to their isotropic response with polarization. (C) 2000 Elsevier Science S.A. All rights reserved.