Non‐classical donor–acceptor chromophores for second order nonlinear optics

Optoelectronic components require materials with large second‐order nonlinearities. Recently, various types of non‐classical chromophores have been developed, in the hope that they have improved physical properties for materials formation. The main research directions and latest developments reviewed here include multi‐dipolar chromophoric assemblies, multiple donor and acceptor chromophores, non‐rod‐shaped dipolar chromophores, and non‐conjugated donor‐acceptor chromophores, in which the charge transfer process is through space instead of the π‐conjugated bridge.