Impurity dephasing by optical modes in polymers and glasses

The contribution of low-lying optical and librational oscillators to the homogeneous linewidth of organic impurities in organic glasses and polymers is calculated in a specific model. The disordered (amorphous) nature of the host system is described by a distribution of two-level systems (TLS) following earlier work. We demonstrate that at low temperatures the contribution to the dephasing from optical modes can dominate that arising from coupling to acoustic phonons due to the different phase-space distributions of these modes. © 1982.