Recent Progress in Molecular Design of Ionic Second-order Nonlinear Optical Materials

Abstract

This chapter deals with recent and important developments in the field of the molecular design of ionic organic materials with and without metals for second-order nonlinear optics. The first section discusses 1) the origin of optical nonlinearity, 2) the relationship between microscopic and macroscopic polarizabilities and 3) the importance of ionic chromophores as second-order nonlinear optical (NLO) materials. The second section reviews 4) the current experimental and theoretical developments in the design of dipolar and octupolar ionic chromophores for second-order nonlinear optics and 5) the progress on zwitterionic second-order NLO materials. The third section presents 6) possible device applications based on ionic chromophores.