Optical limiting and picosecond relaxation of carbocyanines upper electronic states Academic Article uri icon

abstract

  • Nonlinear absorption, anomalous fluorescence and relaxation of high-lying electronic states in six carbocyanine dyes, including cryptocyanine (DCI), DDI, DTDCI, DTTCI, DOTCI and HDIDCI, in solution and in polymer, were studied by means of picosecond transient absorption spectroscopy and nonlinear transmission experiments. Absorption cross-sections of the S1 Sn transition, and decay rates of the second singlet excited state, S2, were measured. All dyes showed strong reverse saturable absorption in the 450-600 nm region with large excited to ground state absorption cross-section ratios. For DTDCI this ratio, at 470 nm, was measured to be 350, which is the largest ever reported. All molecules have shown strong optical limiting effect. However, in all molecules except DCI a saturation of the optical limiting process was observed as expected, owing to relatively long, up to 17.5 ps, lifetime of the S2 state. The S2 state fluorescence quantum yields were also measured. 2002 Published by Elsevier Science B.V.

published proceedings

  • OPTICS COMMUNICATIONS

author list (cited authors)

  • Oulianov, D. A., Dvornikov, A. S., & Rentzepis, P. M.

citation count

  • 17

complete list of authors

  • Oulianov, DA||Dvornikov, AS||Rentzepis, PM

publication date

  • May 2002