Waveplate is an optical device that alters the polarization state of a light wave traveling through it.
Two common types are the half-wave plate and the quarter-wave plate.
Half Waveplate: Primarily functions to rotate the plane of polarization without changing its type. For example, if linearly polarized light is incident at 45 degrees to the fast axis, it will be rotated by 90 degrees.
Quarter Waveplate: Changes the type of polarization. It can convert linear polarization into circular or elliptical polarization depending on the input angle.
