Abstract

The majority of organic nonlinear molecules, although possessing high hyper-polarizabilities, tend to crystallize in centro-symmetric structures leading to a vanishing macroscopic second order susceptibility. One possibility of inducing a noncentro-symmetric structure consists of forming hydrogen bonds with an inorganic group. In this context, organic salts of dihydrogenphosphate, such as pyperidine dihydrogenphosphate [1] and 2-amino-5- nitropyridine dihydrogenphosphate [2] have been synthesized and present reasonable second order nonlinear optical responses. In these materials a cation from a polarizable organic molecule forms a hydrogen bond with the dihyrdogenphosphale anion, leading to an alignment of the polar molecules and consequently to the formation of crystalline salts with large bulk nonlinear susceptibilities.

© 1996 IEEE