Cycloidal diffractive waveplate and method of manufacture

A cycloidal diffractive waveplate comprising:

• a first substrate layer;
• a second substrate layer;
• a liquid crystal layer provided between the first substrate layer and the second substrate layer, the liquid crystal layer formed of liquid crystal molecules each having an optical axis and the liquid crystal layer having a periodic molecular structure, and wherein the liquid crystal layer has a diffractive state in which the optical axes of the liquid crystal molecules are rotated across a plane of the waveplate and a non-diffractive state in which the optical axes of the liquid crystal molecules are orientated in the same direction in the plane of the waveplate;
• and
• a plurality of transparent positive electrodes and a plurality of transparent negative electrodes, the electrodes provided on the first substrate layer and the electrodes arranged in an alternating series, such that when an electric voltage is applied to the electrodes an electric field is produced in the plane of the waveplate and the liquid crystal layer is switched from the diffractive state to the non-diffractive state.