Circular Polarization of Luminescence as a Tool To Study Molecular Dynamical Processes

Circular polarization of luminescence is a phenomenon that can be observed for chiral molecules in isotropic solution, for molecular aggregates and molecular materials. Also, the electroluminescence from chiral molecular materials in organic light emitting diodes can be nearly completely circularly polarized. In this review we focus on the latest developments in experimental results for the categories listed above. A unifying description of the origin of the circular polarization is still missing. We revisit the very earliest efforts to measure and understand circular polarization in light emission in order to better understand the present day confusion on the origins of the polarization. It seems that quantum field theory of electromagnetic interactions could provide leads for a comprehensive description of the circular polarization including contributions from helicity at all possible length scales from the molecular to the macroscopic.