Effective refractive index of a quasi-two-dimensional polydomain film of a conjugated polymer

The relation between the effective ordinary refractive index $n^{*}=(n_{o}n_{e})^{1/2}$ of a quasi-two-dimensional polydomain uniaxial film of a conjugated polymer F8BT in the visible transparency region and the refractive indices $n_{o,e}$ of uniaxial domains with the optical axes randomly oriented in the plane of the film has been confirmed experimentally. The permissible interval of variations in $n^*$ has been established and a strong spectral dispersion of this interval near the long-wavelength electronic absorption band of the film has been demonstrated.