Recent development in the design of organic materials for optical power limiting

During the past five years there has been considerable progress in the design of organic materials for optical power limiting. Among the more promising of the new material approaches are new reverse saturable absorbers (RSA) which derive their limiting capability on the photogeneration of highly absorbing charge states. Equally intriguing are the new approaches to designing chromophores with large two-photon cross-sections which give access to highly absorbing transient excited states. It now seems possible to combine these two new optical limiting paradigms in single structures which may therefore be considered as bimechanistic optical power limiters.