The QWP always transforms circularly polarized light into linearly polarized light. Circular dichroism spectroscopy measures the absorption of circularly polarized light. First note that a quarter-wave plate always transforms circularly polarized light into linearly polarized light. Spin angular momentum of circularly polarized light can be converted into orbital angular momentum. These alternate circular motions produce right and left circularly polarized waves. This creates one of two linear polarizations depending on the handedness the circularly polarized light. If it moves position it moves either circularly or linearly. For right circularly polarized light (RCP), the electric vector rotates clockwise. Indeed, a negative refractive index for circularly polarized waves can also arise from chirality. One solution utilized the principle of reflection of circularly polarized light. Simply put, since circularly polarized light itself is "chiral", it interacts differently with chiral molecules. Circular dichroism (CD) is the differential absorption of left- and right-handed circularly polarized light. Only a few mechanisms in nature are known to systematically produce circularly polarized light. Annular hurricanes have a single eyewall that is larger and circularly symmetric. That is, the two types of circularly polarized light are absorbed to different extents.