Nano fractal diffuser

Abstract

A diffusive device has an array of discrete facets which may be of a size and pattern similar to a fractal. The facet dimensions can be greater than half the wavelength of incident light such that the facets substantially diffract light. A polarizing wire-grid layer comprised of an array of elongated parallel conductive wires with a period less than half the wavelength of incident light may be disposed between, beneath, or above the facets. The wire-grid polarizes the light by substantially reflecting light having an s-polarization orientation and substantially transmitting a portion of light having a p-polarization orientation.

1 . A light diffuser comprising:
 a. a substrate having a top surface and a bottom surface;   b. a layer disposed over the top surface of the substrate; and   c. at least sixteen facets:
 i. having at least two different sizes; 
 ii. having a bottom surface disposed towards the substrate and a top surface opposing the bottom surface; 
 iii. formed in the layer with facet dimensions >λ/2, where λ is the wavelength of light incident on the at least sixteen facets to create a substantially diffuse light beam; and 
 iv. forming distinct groups arranged in a fractal pattern. 
   
     
     
         2 . The light diffuser of  claim 1 , wherein the substrate and the layer are formed of the same material. 
     
     
         3 . The light diffuser of  claim 1 , wherein the substrate and the layer comprise a different material. 
     
     
         4 . The light diffuser of  claim 1 , wherein the facets are locations that are cut into the layer. 
     
     
         5 . The light diffuser of  claim 1 , wherein the at least sixteen facets have at least two different thicknesses. 
     
     
         6 . The light diffuser of  claim 1 , wherein the at least sixteen facets have at least four different thicknesses. 
     
     
         7 . The light diffuser of  claim 1 , wherein the at least sixteen facets have square shapes. 
     
     
         8 . The light diffuser of  claim 1 , wherein the facets are locations that were masked during etching and are raised above surrounding etched locations. 
     
     
         9 . The light diffuser of  claim 1 , wherein the at least one layer comprises at least two layers and the at least sixteen facets are disposed over at least sixteen other facets. 
     
     
         10 . The light diffuser of  claim 9 , wherein the at least two layers are formed of the same material. 
     
     
         11 . The light diffuser of  claim 9 , wherein the at least two layers comprise a different material. 
     
     
         12 . The light diffuser of  claim 1 , wherein the substrate comprises a material that is opaque to the light such that substantially all of the incoming light is diffusely reflected. 
     
     
         13 . The light diffuser of  claim 1 , wherein the at least sixteen facets have at least four different sizes. 
     
     
         14 . The light diffuser of  claim 1 , wherein the facets are a solid material surrounded by areas of the layer which have been removed. 
     
     
         15 . The light diffuser of  claim 1 , wherein the at least sixteen facets comprise areas of the layer which have been removed, and are surrounded by areas of the layer which have not been removed. 
     
     
         16 . The light diffuser of  claim 1 , wherein a distance from the bottom surface of the substrate to a top surface of at least one of the at least sixteen facets is different than a distance from the bottom surface of the substrate to a top surface of another of the at least sixteen facets. 
     
     
         17 . The light diffuser of  claim 1 , wherein areas of the top surface of the substrate which is not covered with any of the at least sixteen facets are covered by a wire grid and the wire grid comprises a non polarizing material. 
     
     
         18 . The light diffuser of  claim 1 , wherein the top surface of the at least sixteen facets is covered with wire grid and the wire grid comprises a non polarizing material. 
     
     
         19 . A light diffuser comprising:
 a. a substrate having a top surface and a bottom surface;   b. at least one layer disposed over the top surface of the substrate; and   c. at least sixteen facets, with a bottom surface disposed towards the substrate and a top surface opposing the bottom surface, formed in one of the at least one layer with facet dimensions >λ/2 where λ is the wavelength of light incident on the at least two facets to create a substantially diffuse light beam.   
     
     
         20 . A light diffuser comprising:
 a. a substrate having a top surface and a bottom surface;   b. a layer, disposed over the top surface of the substrate, and formed of the same material as the substrate; and   c. at least sixteen facets:
 i. having at least four different sizes with at least four different surface areas; 
 ii. having a bottom surface disposed towards the substrate and a top surface opposing the bottom surface; 
 iii. formed in the layer with facet dimensions >λ/2, where λ is the wavelength of light incident on the at least sixteen facets; 
 iv. forming distinct groups arranged in a fractal pattern; and 
 v. substantially diffracting incident light.