Nonlinear optical effects in molecules and polymers: Issues and opportunities

The field of nonlinear optics in molecules and polymers offers challenging opportunities for theorists on both molecular modeling of new structures with enhanced microscopic response and manifestations of bulk effect in nonlinearity. This article presents an experimental point of view in assessing the current status of various theoretical approaches. Experimental results are presented for two model compounds together with predictions by various theoretical models to discuss issues and future opportunities. Three different types of nonlinear optical processes are discussed: (i) second order, (ii) third order, and (iii) photorefractivity. © 1994 John Wiley & Sons, Inc.