Optical-environment-dependent effects on the fluorescence of submonomolecular dye layers on interfaces

Abstract

We investigated laser-induced fluorescence of submonomolecular (spin coated) dye lasers, e.g., of rhodamine 6G and sulforhodamine 101, on glass surfaces. From angle-resolved emission and excitation spectra, we determine the orientation of the emission and absorption dipole moments relative to the surface. From the fluorescence depolarisation at low dye concentrations we determined the angle ψ between the absorption dipole moment and the emission dipole moment in rhodamine 6G to be ψ≈13o±3o. We also measured the intensity quenching and the fluorescence depolarisation as a function of the dye concentration.