Abstract

Molecular systems, in particular polymers, with π-electron donor-acceptor groups are becoming potential candidates in applications where large bandwidth and low costs are desired for electro-optical modulation of optical information. Di-Phenyl molecules including Disperse-Red-1 and Di-Amino-Nitro-Stilbene (DANS) embody most of the requirements in stability, high loading, processability and very large electro-optical figures of merit¹. However little is known about their electronic structure represented by their excited state spectrum and responsible for their nonlinear optical response, for both second and third order. We present a complete spectroscopic study of the DANS molecular system and compare our theoretical predictions to the second order nonlinear spectrum and four third order nonlinear optical spectra of amorphous DANS side-chain polymers. In particular we can successfully explain shifts of the nonlinear spectrum compared to the linear absorption one by properly accounting for Frank-Condon type displacements².

© 1995 Optical Society of America