Abstract

Recent many-electron calculations^1–3 of the nonlinear optical properties of organic conjugated linear and cyclic chains have now demonstrated the dominant role of electron correlation in this important class of molecular structure. The microscopic third-order susceptibility γ_ijkl(−ω₄;ω₁,ω₂,ω₃) in centrosymmetric polyenes, for example, has major contributions resulting from virtual transitions to energetically high lying strongly correlated two-photon π-electron states.

© 1990 Optical Society of America