Calculations of spectral transfer in disordered and low-dimensional systems

Abstract

The time development of the spectral transfer of optical excitations in inhomogeneously broadened systems is investigated as a function of transfer range, concentration of optically active ions and the dimensionality of the system. The equation of motion method is employed to calculate the spin-wave density of states for the equivalent ferromagnet and this is transformed to obtain the time dependence of the narrow band fluorescence. It is found that neighbours out to the fifth shell in a simple cubic lattice are significant for dipole-dipole interactions. Reducing the effective dimensionality of the model leads to a considerably slower spectral redistribution of the fluorescence.