Measurement of absorption cross sections in the long-wavelength region of the S 0S 1 absorption band of dyes

Abstract

In the long-wavelength region of the S 0S 1 absorption band of dyes only a fraction of molecules takes part in the absorption process. The absorption cross section of the molecules involved is deduced from non-linear transmission measurements with picosecond light pulses. The absorption cross sections σ A(ν L) (ν L is the ruby-laser frequency) of 1,1′-diethyl-2,4′-carbocyanine iodide in methanol and oxazine 1 perchlorate in ethanol are determined.