Opto-thermal properties of fibers: 8. Optical and mechanical parameters variations on cold drawn thermally treated nylon 6-6 fibers

Abstract

Refractive indices and birefringence changes with strain produced by different stresses in annealed and unannealed nylon 6-6 fibers (Promilan, Toray Industries Inc. Japan) were measured interferometrically. Calculations were carried out to determine the strain optical coefficient, the orientation factor, the orientation angle, the number of molecules per unit volume, the isotropic refractive index and the virtual refractive index. The effect of the draw ratio on the refractive index profile was studied. The generalized Lorentz–Lorenz equation given by de Vries has been used to compare the results obtained by Hermans' optical orientation function.