Optical display device
AssigneeWave Optics Ltd.
InventorSalim Valera
Life of this patent
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Abstract
An optical display device (600, 700) is disclosed. A diffractive optical element (618, 718) is mounted on a substrate (611, 711). The diffractive optical element comprises a blazed grating (619, 719) and a remnant layer (617, 717) which is formed of the same polymer-based material as the blazed grating. The remnant layer (617, 717) is positioned adjacent the substrate (611, 711) and a refractive index mismatch is provided between the two. The depth of the remnant layer is selected so that light diffracted by the grating and light reflected by the interface re-combine and interfere constructively for selected angles of incidence in order to undergo thin-film interference.
Claims13
An optical display device comprising:
- a substrate;
- and
- a diffractive optical element comprising a surface relief grating and a remnant layer, wherein the remnant layer is provided between the surface relief grating and the substrate, and the remnant layer has an absolute thickness that is less than 500 nm;
- wherein a partially reflective interface is provided between the substrate and the remnant layer, and wherein a thickness of the remnant layer is controlled to enable constructive thin-film interference for light having a predetermined wavelength that is received at the partially reflective interface from the substrate at a predetermined angle of incidence.
A method of manufacture for an optical display device, the method comprising:
- providing a substrate;
- providing a diffractive optical element comprising a surface relief grating and a remnant layer, wherein the remnant layer is provided between the surface relief grating and the substrate, and the remnant layer has an absolute thickness that is less than 500 nm;
- providing a partially reflective interface between the substrate and the remnant layer;
- and
- controlling a thickness of the remnant layer to enable constructive thin-film interference for light having a predetermined wavelength that is received at the partially reflective interface from the substrate at a predetermined angle of incidence.
Dependencies are inferred from the claim text.