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Updated: May 8, 2026

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
Revealing spectral features in two-photon absorption spectrum of Hoechst 33342: a combined experimental and
Joanna Olesiak-Banska1, Katarzyna Matczyszyn, Robert Zaleśny
1Institute of Physical and Theoretical Chemistry, Wrocław University of Technology , Wyb. Wyspiańskiego 27, PL-50370 Wrocław, Poland.
Abstract:
We present the results of wide spectral range Z-scan measurements of the two-photon absorption (2PA) spectrum of the Hoechst 33342 dye. The strongest 2PA of the dye in aqueous solution is found at 575 nm, and the associated two-photon absorption cross section is 245 GM. A weak but clearly visible 2PA band at ∼850 nm is also observed, a feature that could not be anticipated from the one-photon absorption spectrum. On the basis of the results of hybrid quantum mechanics/molecular mechanics calculations, we put forward a notion that the long-wavelength feature observed in the two-photon absorption spectrum of Hoechst 33342 is due to the formation of dye aggregates.
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