Extended conjugation and donor-acceptor substitution to improve the third-order optical nonlinearity of small molecules
- Department of Physics and Center for Optical Technologies, Lehigh University, Bethlehem, Pennsylvania 18015 (United States)
The authors use donor-acceptor substitution to increase the third-order polarizability {gamma} of small cyanoethynylethene molecules by lowering the energy corresponding to the first optical transition. They identify a weak power-law dependence for {gamma} depending on the number of conjugated electrons that separate the donor and acceptors (N{sup 1.5}), which is the result of the two competing contributions that depend on the conjugation length: the energy separation of the ground and first excited states and the strength of the transition dipole matrix elements. The molecules are highly efficient with respect to their small masses and fall within a factor of 50 of the theoretical limit for centrosymmetric molecules, putting them among the best molecules measured to date.
- OSTI ID:
- 20971971
- Journal Information:
- Applied Physics Letters, Vol. 90, Issue 25; Other Information: DOI: 10.1063/1.2750396; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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