High-resolution optical spectroscopy of polymers: Molecular potentials and internal fields

Abstract

Photochemical hole burning is a spectroscopic method which creates, via laser irradiation at low temperatures, narrow persistent dips in the inhomogeneous absorption bands of solids which are doped with appropriate dye molecules. Especially in amorphous samples, the spectral width of these dips can be several orders of magnitude smaller than that of the total inhomogeneous bands. This does not only provide an enormous increase in spectral resolution, but in addition it allows to select very small subsets of absorbers in the sample with accidentally degenerate transition frequencies. It can be shown that by applying external fields, material parameters and molecular potentials can be probed.