Title

Large molecular third-order optical nonlinearities in polarized carotenoids

Authors

Authors

S. R. Marder; W. E. Torruellas; M. BlanchardDesce; V. Ricci; G. I. Stegeman; S. Gilmour; J. L. Bredas; J. Li; G. U. Bublitz;S. G. Boxer

Comments

Authors: contact us about adding a copy of your work at STARS@ucf.edu

Abbreviated Journal Title

Science

Keywords

POLARIZABILITIES; SUSCEPTIBILITY; GENERATION; POLYENES; LENGTH; BETA; Multidisciplinary Sciences

Abstract

Garito and cc-workers have suggested a mechanism to dramatically increase the second hyperpolarizability, gamma, in linear pi-electron-conjugated molecules. Polarization is introduced that leads to a difference between the dipole moments of the molecule's ground state and excited state. Here a series of carotenoids was examined that had increasing intramolecular charge transfer (ICT) from the polyenic chain to the acceptor moiety in the ground state, and gamma was measured for these compounds as a function of wavelength by third-harmonic generation. The compound with the greatest ICT exhibited a 35-fold enhancement of gamma(max) (the gamma measured at the peak of the three-photon resonance) relative to the symmetric molecule beta-carotene, which itself has one of the largest third-order nonlinearities known. Stark spectroscopic measurements revealed the existence of a large difference dipole moment, Delta mu, between the ground and excited state. Quantum-chemical calculations underline the importance of interactions involving states with large Delta mu.

Journal Title

Science

Volume

276

Issue/Number

5316

Publication Date

1-1-1997

Document Type

Article

Language

English

First Page

1233

Last Page

1236

WOS Identifier

WOS:A1997XA49700035

ISSN

0036-8075

Share

COinS