We present a detailed study of the local environmental sensitivity of the commercially available laser dye, Styryl-9M. Positions of the one-photon and two-photon absorption maxima and two-photon absorption minimum of the dye are sensitive to the solvent polarity. In aqueous solution its absorption and fluorescence spectra consist of two peaks whose relative strength depend on the surrounding pH-s. The dye shows one of the highest two-photon absorption cross sections, 700-1300 GM at the peak, among widely available compounds. Comparison of the linear and nonlinear properties shows that its maximum cross section can be described by an effective two-level model. Based on the properties of Styryl-9M we propose a new method of sensing local environment polarity in solutions and biological phantoms. We show that the dye is a promising candidate for two-photon biological imaging and microscopy.

Date Published: 2 September 2008
PDF: 12 pages
Proc. SPIE 7049, Linear and Nonlinear Optics of Organic Materials VIII, 70490Y (2 September 2008); doi: 10.1117/12.792282

Published in SPIE Proceedings Vol. 7049:
Linear and Nonlinear Optics of Organic Materials VIII
Rachel Jakubiak, Editor(s)