Investigation of polarization diffusion and relaxation dynamics of low temperature glasses

We investigated the optical anisotropy and the normalized areas of persistent spectral holes in organic glasses over almost 1 week (4 decades). The systems studied were 1,4-dihydroxyanthraquinone and tetracene in an EtOH/MeOH glass. The areas of the holes decay on a logarithmic time scale, but the anisotropy remains constant. We draw the following conclusions: (i) There is no reorientation of dye molecules in the glass, (ii) Molecules relaxing from the product state reassume the position in the frequency domain and in space which they had before hole burning, (iii) A dye molecule seems to be strongly coupled just to one two level system (TLS).