Magneto-optic measurements of spectral holes

The magneto-optic properties of spectral holes burnt in two porphyrin derivatives (zinc phthalocyanine and zinc octaethylporphyrin) in polymer films are reported. The Zeeman shifts and broadenings observed are anomalously small. This is interpreted as being due to the combined action of local crystal fields and Jahn-Teller effects. Hole magnetic circular dichroism (MCD) spectra are reported for features resulting from burning in both the Q band origin and vibrational sideline regions. The results provide information about the distribution of environmentally induced crystal-field splittings of the (nominally degenerate) excited state. Modelling of hole absorption and MCD provides new insights into the hole-burning processes in these systems.