Waveplates, also known as retarders, transmit light and modify its polarization state without attenuating, deviating, or displacing the beam. They do this by retarding (or delaying) one component of polarization with respect to its orthogonal component. In unpolarized light, waveplates are equivalent to windows – they are both flat optical components through which light passes. Understanding waveplates as they pertain to polarized light is a bit more complex. To simplify the process, consider key terminology and specifications, fabrication, common types, and application examples.