Abstract

There is currently a considerable effort to develop new organic materials with large second-order nonlinear optical susceptibilities because of their potential applications ih optical signal processing and frequency conversion. For nonlinear optical materials with large second-order nonlinearities non-centrosymmetry at both the molecular and the macroscopic levels is a prerequisite for nonvanishing molecular hyperpolarizabilities β and macroscopic susceptibilities χ⁽²⁾. Among the various classes of materials currently investigated, organic crystals play an important role, since a reliable and a time-constant orientation of a hyperpolarizable chromophore in the lattice can be imposed. To date, organic crystals that have been developed for applications in nonlinear optics have been built from donor-acceptor conjugated molecules.

© 1995 Optical Society of America