Anisotropically formed diffraction grating device
AssigneeFacebook Technologies, LLC
InventorGiuseppe Calafiore
Life of this patent
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Abstract
A diffraction grating includes a substrate and an array of triangular ridges extending from the substrate. The ridges run parallel to one another and have triangular cross-sections such that first sides of the ridges face in a first direction and adjacent second sides of the ridges face in a second, different direction. An array of grating lines is disposed over the first sides of the array of ridges, each grating line of the array of grating lines comprising a slab of transparent material supported by the first side of a corresponding ridge of the array of ridges. A refractive index of the array of grating lines is different from a refractive index of the array of ridges.
Claims15
A method of manufacturing a diffraction grating, the method comprising:
- forming an array of ridges extending from a substrate, the ridges running parallel to one another and having triangular cross-sections, such that first sides of the ridges face in a first direction and adjacent second sides of the ridges face in a second, different direction;
- forming an array of grating lines over the first sides of the array of ridges, each grating line of the array of grating lines comprising a slab of transparent material supported by the first side of a corresponding ridge of the array of ridges;
- forming an overcoat layer over the array of grating lines, the overcoat layer having a substantially flat top surface opposite the substrate;
- and
- wherein a refractive index of the array of grating lines is different from a refractive index of the array of ridges.
A method of manufacturing a diffraction grating, the method comprising:
- forming an array of ridges extending from a substrate, the ridges running parallel to one another and having triangular cross-sections, such that first sides of the ridges face in a first direction and adjacent second sides of the ridges face in a second, different direction;
- and
- forming an array of grating lines over the first sides of the array of ridges, each grating line of the array of grating lines comprising a slab of transparent material supported by the first side of a corresponding ridge of the array of ridges;
- wherein the array of grating lines is formed such that no grating lines are present on the second sides of the ridges;
- and
- wherein the array of grating lines is formed using a directional deposition of a grating layer material over the first sides of the array of ridges.
A method of manufacturing a diffraction grating, the method comprising:
- forming an array of ridges extending from a substrate, the ridges running parallel to one another and having triangular cross-sections, such that first sides of the ridges face in a first direction and adjacent second sides of the ridges face in a second, different direction;
- and
- forming an array of grating lines over the first sides of the array of ridges, each grating line of the array of grating lines comprising a slab of transparent material supported by the first side of a corresponding ridge of the array of ridges;
- wherein vertical projections of neighboring grating lines of the array of grating lines onto the substrate overlap each other.
Dependencies are inferred from the claim text.