Multilayer wire-grid polarizer

• US 7,570,424 B2
• Filed: 12/06/2004
• Issued: 08/04/2009
• Est. Priority Date: 12/06/2004
• Status: Active Grant

• Current Assignee: Moxtek (Polatechno Co.,Ltd.)
• Original Assignee: Moxtek (Polatechno Co.,Ltd.)
• Inventors: Hansen, Douglas P., Perkins, Raymond T., Cheng, Cheng-Yuan, Gardner, Eric W.
• Primary Examiner(s): Lavarias; Arnel C
• Application Number:
  US11/005,927
• Publication Number:
  US 20060119937A1
• Time in Patent Office: 1,702 Days
• Field of Search: 359/486
• US Class Current: 359/485.05
• CPC Class Codes: G02B 5/3058 comprising electrically conductive elements, e.g. wire grids, conductive particles

Abstract

A multilayer wire-grid polarizer for polarizing light includes a stack of thin film layers disposed over a substrate, including a wire-grid array of elongated metal elements having lengths longer than a wavelength of the light and a period less than half the wavelength of the light. One of the layers can include a thin film layer with a refractive index greater than a refractive index of the substrate. One of the thin film layers can include a dielectric array of non-metal elements.

Claims

1. A wire-grid polarizer device for polarizing light, comprising:

a) a substrate;

b) a wire-grid layer, disposed over the substrate, the wire-grid layer including an array of elongated metal elements having lengths longer than a wavelength of the light and a period less than half the wavelength of the light and defining gaps between the elements;

c) at least three continuous thin film layers, disposed between the substrate and the wire-grid layer and extending between the gaps, the thin film layers having different refractive indices with respect to one another;

d) the refractive index of at least one of the three thin film layers being greater than a refractive index of the substrate; and

e) at least one of the thin film layers includes a dielectric grid including an array of non-metal elements, the non-metal and metal elements of the arrays being oriented substantially parallel with one another, and the arrays having substantially equal periods.

2. A device in accordance with claim 1, wherein the at least three thin film layers are formed of materials selected from the group consisting of:

aluminum oxide;

antimony trioxide;

antimony sulphide;

beryllium oxide;

bismuth oxide;

bismuth triflouride;

cadmium sulphide;

cadmium telluride;

calcium fluoride;

eerie oxide;

chiolite;

cryolite;

germanium;

hafhnium 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; and

zirconium dioxide.

3. A device in accordance with claim 1, wherein non-metal elements of the dielectric grid are aligned below the metal elements of the wire grid layer.

4. A device in accordance with claim 1, further comprising:

at least one other thin film layer, disposed over the wire-grid layer.

5. A device in accordance with claim 4, wherein the at least one other thin film layer includes a dielectric grid including an array of non-metal elements, the non-metal and metal elements of the arrays being oriented substantially parallel with one another, and the arrays having substantially equal periods.

6. A device in accordance with claim 5, wherein non-metal elements of the dielectric grid are aligned above the metal elements of the wire grid layer.

7. A device in accordance with claim 1, wherein the elongated metal elements include alternating layers of metal and non-metal materials.

8. A device in accordance with claim 1, wherein at least one of the at least three continuous thin film layers entirely cover a surface of the substrate.

9. A wire-grid polarizer device for polarizing light, comprising:

a) a substrate;

b) a wire-grid layer, disposed over the substrate, the wire-grid layer including an array of elongated metal elements having lengths longer than a wavelength of the light and a period less than half the wavelength of the light and defining gaps between the elements;

c) a first dielectric-grid layer, disposed over the wire-grid layer, the dielectric-grid layer including an array of non-metal elements; and

d) a plurality of continuous thin film layers with different refractive indices with respect to one another, disposed between the wire-grid layer and the dielectric-grid layer and extending between the gaps; and

e) at least one of the plurality of continuous thin film layers including a second dielectric grid layer, the second dielectric-grid layer including an array of non-metal elements, the non-metal and metal elements of the arrays being oriented substantially parallel with one another, and the arrays having substantially equal periods.

10. A device in accordance with claim 9, wherein non-metal elements of the second dielectric grid layer are aligned above the metal elements of the wire grid layer.

11. A device in accordance with claim 9, wherein at least one of the plurality of continuous thin film layers entirely covers a surface of the substrate.

12. A wire-grid polarizer device for polarizing light, comprising:

a) a substrate;

b) a wire-grid layer, disposed over the substrate, the wire-grid layer including an array of elongated metal elements having lengths longer than a wavelength of the light and a period less than half the wavelength of the light and defining gaps between the elements;

c) at least three continuous thin film layers, disposed between the substrate and the wire-grid layer and extending between the gaps, the thin film layers having different refractive indices with respect to one another;

d) the refractive index of at least one of the three thin film layers being greater than a refractive index of the substrate; and

e) at least one other thin film layer, disposed over the wire-grid layer and including a dielectric grid including an array of non-metal elements, the non-metal and metal elements of the arrays being oriented substantially parallel with one another, and the arrays having substantially equal periods.

13. A device in accordance with claim 12, wherein the at least three thin film layers are formed of materials 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; and

zirconium dioxide.

14. A device in accordance with claim 12, wherein one of the thin film layers includes a dielectric grid including an array of non-metal elements, the non-metal and metal elements of the arrays being oriented substantially parallel with one another, and the arrays having substantially equal periods.

15. A device in accordance with claim 14, wherein non-metal elements of the dielectric grid are aligned below the metal elements of the wire grid layer.

16. A device in accordance with claim 12, wherein non-metal elements of the dielectric grid are aligned above the metal elements of the wire grid layer.

17. A device in accordance with claim 12, wherein the elongated metal elements include alternating layers of metal and non-metal materials.

18. A device in accordance with claim 12, wherein the at least one of the at least three continuous thin film layers entirely cover a surface of the substrate.

19. A wire-grid polarizer device for polarizing light, comprising:

a) a substrate;

b) a wire-grid layer, disposed over the substrate, the wire-grid layer including an array of elongated metal elements having lengths longer than a wavelength of the light and a period less than half the wavelength of the light and defining gaps between the elements;

c) a first dielectric-grid layer, disposed over the wire-grid layer, the dielectric-grid layer including an array of non-metal elements;

d) a plurality of continuous thin film layers with different refractive indices with respect to one another, disposed between the wire-grid layer and the dielectric-grid layer; and

e) at least one of the plurality of continuous thin film layers including a second dielectric grid layer, the second dielectric-grid layer including an array of non-metal elements, the non-metal and metal elements of the arrays being oriented substantially parallel with one another, and the arrays having substantially equal periods.