Fractal interpretation of non-Lorentzian persistent hole shapes in organic glasses

Non-Lorentzian persistent hole shapes of chromophore in organic glasses have been explained by considering fractal structures of the organic glass hosts. The measured hole shape is well reproduced by the Fourier transform of the non-exponentially decaying function of τ, exp(-cTτ^D/3), where c is a constant, T is the temperature, and D is the fractal dimension of the glass host. The fractal dimension D obtained by fitting the theoretical curve to the observed hole shape of oxazine 1 in polyvinyl alcohol glass is 2.3 ± 0.1 and that of oxazine 1 in ethanol glass is 2.9 ± 0.1. These values of fractal dimension are in good agreement with the values obtained in our previous experiment in both glass hosts doped with a different chromophore, HITC.