Flow birefringence and dichroism of polymers. I. General theory and application to the dilute case

Birefringence of polymer solutions has two origins, the orientation of polymer segments (the intrinsic birefringence), and the anisotropy of the segment density correlation function (the form birefringence). Rigorous formulas are given for the two contributions. Also special attention is focused on the form dichroism, which seems to have potential applicability in the study of polymer dynamics. As the simplest application we examine the birefringence and dichroism of dilute solutions in weak oscillatory shear for arbitrary light wavelength.