Polarization optical device and manufacturing method therefor
AssigneeRicoh Optical Industries Co., Ltd.
InventorKazuhiro Umeki
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Abstract
A polarization optical device is disclosed that includes: an inorganic dielectric substrate transparent with respect to incident light having a flat surface; and an array of strips of conductive elements embedded from the flat surface of the inorganic dielectric substrate to a uniform depth, with an equal width, and with an equal separation in a pitch shorter than the wavelength of the incident light in a manner such that the surfaces of the strips of conductive elements are flush with the surface of the substrate.
Claims34
A polarization optical device comprising:
- an inorganic dielectric substrate transparent with respect to incident light having a flat surface;
- and
- an array comprising a plurality of strips of conductive elements embedded in the flat surface of said inorganic dielectric substrate to an equal depth, with an equal width, and with an equal separation in a pitch shorter than the wavelength of the incident light in a manner such that the surfaces of said strips of conductive elements are flush with the surface of said substrate.
A manufacturing method for a polarization optical device, comprising the steps of:
- a) manufacturing a metal mold having a surface shape of fine structure comprising an array of projections arranged with an equal separation in a pitch shorter than the wavelength of incident light with an equal height and an equal width on a flat surface;
- b) pressing a product substrate onto said metal mold via hardenable resin and transferring the surface shape of said metal mold to said resin on said product substrate;
- c) hardening said resin;
- d) removing said metal mold from said resin in a state in which said resin is bonded with said product substrate;
- e) transferring the surface shape once transferred into said resin in said step b) to a surface of said product substrate according to a dry etching method;
- and
- f) filling in depressions formed in said surface of said product substrate in said step e), with metal.
A polarization optical device comprising:
- an inorganic dielectric substrate transparent with respect to incident light and having a flat surface;
- an array comprising a plurality of strips of conductive elements provided on the flat surface of said inorganic dielectric substrate with an equal height, with an equal width, and with an equal separation in a pitch shorter than the wavelength of the incident light;
- and
- a protective layer, transparent with respect to the incident light and having a flat surface, provided on the surface of said inorganic dielectric substrate including said strips of conductive elements.
A manufacturing method for a polarization optical device, comprising the steps of:
- a) manufacturing a metal mold having a surface of fine shape comprising an array of depressions arranged with an equal separation in a pitch shorter than the wavelength of incident light with an equal depth and an equal width on a flat surface;
- b) forming a metal layer on a surface of a product substrate;
- c) pressing said metal layer of the product substrate onto said metal mold via a hardenable resin and transferring the surface shape of said metal mold to said resin on said metal layer;
- d) hardening said resin;
- e) removing said metal mold from said resin in a state in which said resin is bonded with said metal layer;
- f) further transferring the surface shape once transferred to said resin in said step c) to a surface of said metal layer in a dry etching method so as to form an array of strips of conductive elements;
- g) forming a protective layer on the product substrate including the strips of conductive elements;
- and
- h) flattening a surface of said protective layer.
Dependencies are inferred from the claim text.