A system includes a diffractive optical element configured to receive a first beam and a second beam interfering with one another to generate a first interference pattern. The diffractive optical element is also configured to forwardly diffract the first beam and the second beam to output a third beam and a fourth beam. The third beam and the fourth beam interfere with one another to generate a second interference pattern. The system also includes a detector configured to detect the second interference pattern.

A device includes a display configured to generate an image light. The device also includes a waveguide optically coupled with the display and configured to guide the image light to an exit pupil of the device. The waveguide includes a grating including a birefringent material, and a birefringence of the grating is configured to increase along a pupil-expanding direction of the device.

A method is provided. The method includes directing a first beam to a polarization sensitive recording medium. The method also includes directing a second beam to the polarization sensitive recording medium to interfere with the first beam to generate a polarization interference pattern, to which the polarization sensitive recording medium is exposed. One of the first beam and the second beam has a planar wavefront and the other has a non-planar wavefront. A first propagation direction of the first beam and a second propagation of the second beam are non-parallel.

A polarization volume hologram (PVH) lens includes a PVH layer having a freeform design. The PVH layer includes a first region and a second region having different optical properties.

A method for manufacturing a radial or azimuthal polarization conversion component comprises the steps of: placing a holographic recording material between two right-angle prisms, wherein the holographic recording material is divided into at least four sector-shaped areas and is partially shielded, and only one of the sector-shaped areas is exposed each time; allowing a recording light to pass through the right-angle prisms and the exposed sector-shaped area of the holographic recording material and to interfere with a reflected object light on the holographic recording material; rotating the holographic recording material to expose the other sector-shaped areas one by one to be constructed for manufacturing volume holograms with diffraction angles of 48.19 degrees, 60 degrees or about 85 degrees.