The authors consider photochem. hole burning of an inhomogeneous and isotropic ensemble of chromophores through excitation with a narrow-bandwidth source of polarized light. The authors derive expressions for the depth and anisotropy of resonant and vibronic satellite spectral holes with increasing fluence. A fit of these satn. curves to exptl. data yields the Debye-Waller factor of the system. A simple rate equation model predicts that the anisotropy of a spectral hole depends only on the angle between the transition dipoles of the burnt and the probed transitions. In expts. with pulsed lasers strong deviations from this ideal behavior are obsd. An extended theory including satn. gives a satisfactory description of this phenomenon and provides a new method for the detn. of photochem. quantum yields.