Study of absorption spectrum and dynamics evaluation of the indocyanine-green first singlet excited state

Excited state absorption and excited state dynamics of indocyanine-green (ICG) dissolved in dymethyl sulfoxide were measured using white-light continuum Z-scan (WLCZScan) and white-light continuum pump-probe (WLCPP) techniques. The excited state absorption spectrum, obtained through Z-scan measurements, revealed saturable absorption (SA) for wavelengths longer than 630 nm, while reverse saturable absorption (RSA) appeared, as indicated by a band at approximately 570 nm. Both processes were modeled by a three-energy-level diagram, from which the excited state cross-section values were determined. SA and RSA were also observed in pump-probe experiments, with a recovery time in the hundreds of picoseconds time scale due to the long lifetime of the first excited state of ICG. Such results contribute to the understanding of ICG optical properties, allowing application in photonics and medicine. Copyright (C) 2010 John Wiley & Sons, Ltd.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo)

CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

CAPES (Coordenacao de Aperfeicoamento de Pesoal de Nivel Superior)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Air Force Office of Scientific Research (AFOSR) [FA9550-07-1-0374]

U.S. Air Force Office of Scientific Research (AFOSR)