Two-photon anisotropy: Analytical description and molecular modeling for symmetrical and asymmetrical organic dyes

Jie Fu, Olga V. Przhonska, Lazaro A. Padilha, David J. Hagan, Eric W. Van Stryland, Kevin D. Belfield, Mikhail V. Bondar, Yuriy L. Slominsky, Alexei D. Kachkovski

Research output: Contribution to journalArticlepeer-review

41 Scopus citations


One- and two-photon anisotropy spectra of a series of symmetrical and asymmetrical polymethine (PD) and fluorene molecules were measured experimentally and discussed theoretically within the framework of three-state and four-state models. For all the molecules discussed in this paper, the experimental two-photon anisotropy values, r2PA, lie in the relatively narrow range from 0.47 to 0.57 and remain almost independent of wavelength over at least two electronic transitions. This is in contrast with their one-photon anisotropy, which shows strong wavelength dependence, typically varying from ≈0 to 0.38 over the same transitions. A detailed analysis of the two-photon absorption (2PA) processes allows us to conclude that a three-state model can explain the 2PA anisotropy spectra of most asymmetrical PDs and fluorenes. However, this model is inadequate for all the symmetrical molecules. Experimental values of r2PA for symmetrical polymethines and fluorenes can be explained by symmetry breaking leading to the deviation of the orientation of the participating transition dipole moments from their "classical" orientations.

Original languageEnglish (US)
Pages (from-to)257-268
Number of pages12
JournalChemical Physics
Issue number3
StatePublished - Feb 6 2006
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy
  • Physical and Theoretical Chemistry


  • Fluorenes
  • One- and two-photon anisotropy
  • Polymethine dyes
  • Symmetry breaking
  • Transition dipole moments
  • Two-photon absorption


Dive into the research topics of 'Two-photon anisotropy: Analytical description and molecular modeling for symmetrical and asymmetrical organic dyes'. Together they form a unique fingerprint.

Cite this