Problem 5.193

Plane-polarized light of wavelength $589 \mathrm{nm}$ propagates along the axis of a cylindrical glass vessel filled with slightly turbid sugar solution of concentration $500 \mathrm{~g} / \mathrm{l}$. Viewing from the side, one can see a system of helical fringes, with $50 \mathrm{~cm}$ between neighbouring dark fringes along the axis. Explain the emergence of the fringes and determine the specific rotation constant of the solution.