Multilayer wire-grid polarizer with off-set wire-grid dielectric grid

Abstract

A wire-grid polarizer includes a stack of thin film layers disposed over a substrate including a wire grid layer and a plurality of thin film layers disposed between the wire grid layer and the substrate. The wire-grid layer includes an array of elongated metal elements, comprising lengths longer than a wavelength of visible light, a period less than 200 nanometers, a height less than 400 nanometers; and a material selected from the group consisting of aluminum, silver, gold, copper, or combinations thereof. The plurality of thin film layers disposed between the wire grid layer and the substrate include at least one dielectric grid layer and at least one thin film layer comprising silicon. The dielectric grid layer and the wire-grid are substantially parallel with one another, have substantially equal periods, and have substantially equal widths.

1 . A wire-grid polarizer device for polarizing light, comprising:
 a) a stack of thin film layers disposed over a substrate including:   b) a wire grid layer and a plurality of thin film layers disposed between the wire grid layer and the substrate;   c) the wire-grid layer including an array of elongated metal elements, wherein the elements comprise:
 i. lengths longer than a wavelength of visible light; 
 ii. a period less than 200 nanometers; 
 iii. a height less than 400 nanometers; and 
 iv. a material selected from the group consisting of aluminum, silver, gold, copper, or combinations thereof; 
   d) the plurality of thin film layers disposed between the wire grid layer and the substrate including:
 i. at least one dielectric grid layer; and 
 ii. at least one thin film layer comprising silicon; and 
   e) the dielectric grid layer and the wire-grid are substantially parallel with one another, have substantially equal periods, and have substantially equal widths.   
     
     
         2 . The device of  claim 1 , wherein at least one of the plurality of thin film layers disposed between the wire grid layer and the substrate has a thickness and material selected for decreasing reflection of p polarized light. 
     
     
         3 . The device of  claim 1 , wherein the substrate comprises glass or quartz. 
     
     
         4 . The device of  claim 1 , wherein the dielectric grid comprises at least two contiguous dielectric grids and at least one of the dielectric grids comprises a material selected from the group consisting of aluminum oxide; antimony trioxide; antimony sulphide; beryllium oxide; bismuth oxide; bismuth triflouride; cadmium sulphide; cadmium telluride; calcium fluoride; ceric oxide; chiolite; cryolite; germanium; hafnium dioxide; lanthanum fluoride; lanthanum oxide; lead chloride; lead fluoride; lead telluride; lithium fluoride; magnesium fluoride; magnesium oxide; neogymium fluoride; neodymium oxide; praseodymium oxide; scandium oxide; silicon; silicon oxide; disilicon trioxide; silicon dioxide; sodium fluoride; tantalum pentoxide; tellurium; titanium dioxide; thallous chloride; yttrium oxide; zinc selenide; zinc sulphide; zirconium dioxide; and combinations thereof. 
     
     
         5 . The device of  claim 1 , wherein the metal elements have a height less than 200 nanometers. 
     
     
         6 . The device of  claim 1 , further comprising at least one thin film disposed on top of the wire grid. 
     
     
         7 . The device of  claim 1 , further comprising at least two thin films disposed on top of the wire grid and wherein at least one of the at least two thin films disposed on top of the wire grid has a thickness and material selected for decreasing reflection of p polarized light. 
     
     
         8 . A wire-grid polarizer device for polarizing light, comprising:
 a) a stack of thin film layers disposed over a substrate including a wire grid layer and a dielectric thin film layer;   b) the wire-grid layer including an array of elongated metal elements, wherein the elements comprise:
 i. lengths longer than a wavelength of visible light; 
 ii. a period less than 200 nanometers; 
 iii. a height less than 400 nanometers; and 
 iv. a material selected from the group consisting of aluminum, silver, gold, copper, or combinations thereof; 
   c) the dielectric thin film layer disposed between the wire grid layer and the substrate; and   d) the dielectric thin film layer comprising:
 i. a material having a refractive index greater than a refractive index of the substrate; and 
 ii, a material selected from the group consisting of aluminum oxide; antimony trioxide; antimony sulphide; beryllium oxide; bismuth oxide; bismuth triflouride; cadmium sulphide; cadmium telluride; calcium fluoride; ceric oxide; chiolite; cryolite; germanium; hafnium dioxide; lanthanum fluoride; lanthanum oxide; lead chloride; lead fluoride; lead telluride; lithium fluoride; magnesium fluoride; magnesium oxide; neogymium fluoride; neodymium oxide; praseodymium oxide; scandium oxide; silicon; silicon oxide; disilicon trioxide; silicon dioxide; sodium fluoride; tantalum pentoxide; tellurium; titanium dioxide; thallous chloride; yttrium oxide; zinc selenide; zinc sulphide; zirconium dioxide; and combinations thereof. 
   
     
     
         9 . The device of  claim 8 , further comprising at least one thin film disposed on top of the wire grid. 
     
     
         10 . The device of  claim 8 , further comprising at least two thin films disposed on top of the wire grid and wherein at least one of the at least two thin films disposed on top of the wire grid has a thickness and material selected for decreasing reflection of p polarized light. 
     
     
         11 . The device of  claim 8 , wherein:
 a) the dielectric thin film layer comprises at least two contiguous dielectric grids;   b) at least one of the at least two contiguous dielectric grids comprises silicon; and   c) the dielectric grids and the wire-grid are substantially parallel with one another and have substantially equal periods.   
     
     
         12 . The device of  claim 11 , wherein the dielectric grids and the wire-grid have substantially equal widths. 
     
     
         13 . The device of  claim 8 , wherein the dielectric thin film layer has a thickness and material selected for decreasing reflection of p polarized light. 
     
     
         14 . The device of  claim 8 , wherein the metal elements have a height less than 200 nanometers. 
     
     
         15 . A wire-grid polarizer device for polarizing light, comprising:
 a) a stack of thin film layers disposed over a substrate including a wire grid layer and a dielectric thin film layer;   b) the wire-grid layer including an array of elongated metal elements, wherein the elements comprise:
 i. lengths longer than a wavelength of visible light; 
 ii. a period less than 200 nanometers; 
 iii. a height less than 400 nanometers; and 
 iv. a material selected from the group consisting of aluminum, silver, gold, copper, and combinations thereof; and 
   c) the dielectric thin film layer having a refractive index greater than a refractive index of the substrate.   
     
     
         16 . The device of  claim 15 , wherein the dielectric thin film layer has a thickness and material selected for decreasing reflection of p polarized light. 
     
     
         17 . The device of  claim 15 , wherein the dielectric thin film layer comprises silicon. 
     
     
         18 . The device of  claim 15 , wherein the dielectric thin film layer comprises at least two contiguous dielectric thin film layers and wherein at least one of the dielectric thin film layers is a dielectric grid and at least one of the dielectric thin film layers is continuous. 
     
     
         19 . The device of  claim 15 , wherein the metal elements have a height less than 200 nanometers. 
     
     
         20 . The device of  claim 15 , wherein the substrate comprises glass or quartz.