Interference polarizing (Pluta and Interphako) microscopes have been used to measure the birefringence and refractive indices during the cold-drawing of isotactic poly(propylene) (iPP), poly(tetrafluoroethylene) (PTFE) and poly(vinylidene fluoride) (PVDF) fibres. The intrinsic birefringence (Δn0) and refractive indices (niso, and ) of iPP, PTFE and PVDF fibres were interferometrically predicted using affine and pseudo-affine models. In terms of these intrinsic values, a new way of calculating the orientation parameter is discussed. A selection of microinterferograms is given for illustration.
El-Dessouky, H. M., Lawrence, C. A., Voice, A. M., Lewis, E. L. V., & Ward, I. M. (2007). An interferometric prediction of the intrinsic optical properties for cold-drawn iPP, PTFE and PVDF fibres. Journal of Optics A: Pure and Applied Optics, 9(11), 1041-1047. https://doi.org/10.1088/1464-4258/9/11/012