Journal of Fluorescence

, Volume 20, Issue 1, pp 197–202

Excited State Absorption Study in Hematoporphyrin IX

  • Leonardo De Boni
  • Carlos Toro
  • Florencio E. Hernandez
Original Paper

DOI: 10.1007/s10895-009-0538-z

Cite this article as:
De Boni, L., Toro, C. & Hernandez, F.E. J Fluoresc (2010) 20: 197. doi:10.1007/s10895-009-0538-z

Abstract

We present the study of the excited state absorption of Hematoporphyrin IX dissolved in dimethyl sulfoxide. All measurements were carried out using open aperture Z-scan and white-light continuum pump-probe with picosecond pulses to avoid triplet excited state absorption. Without the latter contribution, the results obtained with both techniques show a transition to a high singlet excited state. The vibronic progression of the Q-band is observed due to photobleaching of the ground state. In addition, we show that the excited state presents reverse saturable absorption for most of the spectral range studied. A long relaxation component of the first singlet excited state was evidenced with the pump-probe experiment. This result is in agreement with fluorescence lifetime and fluorescence quantum yield measurements. In order to elucidate the origin of the nonlinear effects, we used a three-level energy diagram to describe the principal singlet-singlet transitions.

Keywords

Excited state absorption Photodynamic therapy Multiphoton absorption Porphyrin 

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Leonardo De Boni
    • 1
  • Carlos Toro
    • 1
  • Florencio E. Hernandez
    • 1
    • 2
  1. 1.Department of ChemistryUniversity of Central FloridaOrlandoUSA
  2. 2.CREOL/The College of Optics and PhotonicsUniversity of Central FloridaOrlandoUSA

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