Description of complex strain-optical coefficient by the Fractional Standard Solid Model

The fractional standard solid model for viscoelasticity is recalled. In association with an existing model for birefringence in polymers, it allows interpretation of literature data on dynamic birefringence in polycarbonate in the glass transition range. This model, which does not require validity of the frequency-temperature superposition principle, is compared with Inoue et al´s decomposition into rubbery and glassy components of relaxation functions