Spatially variable liquid crystal diffraction gratings

A method of fabricating a diffraction grating, the method comprising:

• providing a plurality of different diffracting zones on a substrate, the plurality of different diffracting zones arranged laterally in a lateral direction substantially parallel to a major surface of the substrate and having a periodically repeating lateral dimension corresponding to a grating period adapted for light diffraction;
• and
• forming a plurality of different liquid crystal layers to form the diffraction grating, the plurality of different liquid crystal layers comprising liquid crystal molecules over the substrate, the plurality of different liquid crystal layers arranged differently in different diffracting zones to diffract light passing therethrough,
• wherein the different liquid crystal layers include liquid crystal molecules that are aligned differently,
• wherein the different liquid crystal layers of the different diffracting zones are formed in the lateral direction as a continuous layer contacting a common surface over the substrate, and
• wherein the different liquid crystal layers comprise corresponding regions in which the liquid crystal molecules have substantially different alignment angles with respect to a reference direction, such that the different diffracting zones have different optical properties associated with light diffraction.