A first layer of anisotropic material extends along a first plane and includes anisotropic components being parallel to a second plane non-parallel and non-perpendicular to the first plane. The anisotropic components are arranged in cycloidal or helical patterns. The cycloidal or helical patterns define one or more Bragg planes that are non-parallel and non-perpendicular to the first plane and either substantially parallel or substantially perpendicular to the second plane.

The objective of the present invention is providing a method for fabricating high quality diffractive waveplates and their arrays that exhibit high diffraction efficiency over large area, the method being capable of inexpensive large volume production. The method uses a polarization converter for converting the polarization of generally non-monochromatic and partially coherent input light beam into a pattern of periodic spatial modulation at the output of said polarization converter. A substrate carrying a photoalignment layer is exposed to said polarization modulation pattern and is coated subsequently with a liquid crystalline material. The high quality diffractive waveplates of the present invention are obtained when the exposure time of said photoalignment layer exceeds by generally an order of magnitude the time period that would be sufficient for producing homogeneous orientation of liquid crystalline materials brought in contact with said photoalignment layer. Compared to holographic techniques, the method is robust with respect to mechanical noises, ambient conditions, and allows inexpensive production via printing while also allowing to double the spatial frequency of optical axis modulation of diffractive waveplates.

An apparatus and method for fabricating high quality one- or two-dimensional diffractive waveplates and arrays that exhibit high diffraction efficiency and capable of inexpensive large volume production. A generally non-holographic and aperiodic polarization converter for converting the polarization of a coherent input light beam of a visible wavelength into a pattern of continuous spatial modulation at the output of the polarization converter. A photoresponsive material characterized by an anisotropy axis according to polarization of the light beam is exposed to a polarization modulation pattern and coated subsequently with an anisotropic material overlayer with ability of producing an optical axis orientation according to and under the influence of the anisotropy axis of the photoresponsive material layer. The diffractive waveplates are obtained when exposure time of photoresponsive material layer exceeds an order of magnitude the time period that is known to produce spatially homogeneous orientation of the anisotropic overlayer.