Envisics Ltd

A method is provided of manufacturing a waveguide comprising an input port, an output port, a transparent medium having a first refractive index (n 1 ), a first pair of opposing surfaces and a second pair of opposing surfaces. The method comprises polishing at least one surface of the second pair of opposing surfaces to achieve a separation therebetween, bonding a protective layer to at least one polished surface of the second pair of opposing surfaces; and polishing at least one surface of the first pair of opposing surfaces to achieve a separation therebetween.

A method of fabricating an electrically-controlled birefringence cell. The cell has a cell gap no more than 20 micrometers. The cell has an alignment layer arranged to impart a pretilt on liquid crystal in contact with the alignment layer. The method comprises processing the alignment layer to achieve a surface anchoring value between the liquid crystal and alignment layer of less than 1 mJ/m 2 .

A holographic projector includes a waveguide that includes a pair of opposing reflective surfaces arranged to receive and waveguide a hologram/holographic wavefront therebetween. A first surface of the pair of complementary surfaces is partially reflective-partially transmissive such that a plurality of replicas of the hologram/holographic wavefront are emitted therefrom. The holographic projector further includes a diffractive optical element arranged to receive the plurality of replicas of the hologram/holographic wavefront from the first surface of the waveguide and principally redirect each replica into a respective non-zero diffractive order defined by a diffraction angle. The holographic projector also includes an array of louvres arranged to receive the hologram/holographic wavefront from the diffractive optical element, where the array of louvres is substantially transmissive at the non-zero diffraction angle and substantially non-transmissive at a zeroth diffraction angle of the diffractive optical element.

A method is provided of manufacturing a waveguide comprising an input port, an output port, a transparent medium having a first refractive index (n 1 ), a first pair of opposing surfaces and a second pair of opposing surfaces. The method comprises polishing at least one surface of the second pair of opposing surfaces to achieve a separation therebetween, bonding a protective layer to at least one polished surface of the second pair of opposing surfaces; and polishing at least one surface of the first pair of opposing surfaces to achieve a separation therebetween.

A diffractive structure arranged to spatially modulate light transformable by a viewing system into a target image. The diffractive structure is configured to generate a plurality of discrete light patterns. Each light pattern corresponds to a different part of the target image. The shape of each discrete light pattern substantially corresponds to the shape of an entrance aperture of the viewing system.

A method of fabricating an electrically-controlled birefringence cell. The cell has a cell gap no more than 20 micrometers. The cell has an alignment layer arranged to impart a pretilt on liquid crystal in contact with the alignment layer. The method comprises processing the alignment layer to achieve a surface anchoring value between the liquid crystal and alignment layer of less than 1 mJ/m 2 .