Multilayer wire-grid polarizer

• US 20060119937A1
• Filed: 12/06/2004
• Published: 06/08/2006
• Est. Priority Date: 12/06/2004
• Status: Active Grant

• Current Assignee: Moxtek Inc (Nippon Kayaku Company Limited)
• Original Assignee: Moxtek Inc (Nippon Kayaku Company Limited)
• Inventors: Hansen, Douglas P., Perkins, Raymond T., Cheng, Cheng-Yuan, Gardner, Eric W.
• Granted Patent: US 7,570,424 B2
• Time in Patent Office: Days
• US Class Current: 359/486
• CPC Class Codes: G02B 5/3058 comprising electrically conductive elements, e.g. wire grids, conductive particles

Abstract

A mulitlayer 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) at least two thin film layers, disposed on the substrate, the thin film layers having different refractive indices with respect to one another;

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

d) a wire-grid layer, disposed over the at least two thin film layers, 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.

2. A device in accordance with claim 1, wherein the at least two thin film layers include at least three thin film layers.

3. A device in accordance with claim 1, wherein the at least two thin film layers extend continuously across the substrate.

4. A device in accordance with claim 1, wherein the at least two 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.

5. A device in accordance with claim 1, 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.

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

7. A device in accordance with claim 5, wherein non-metal elements of the dielectric grid are off-set below the metal elements of the wire grid layer.

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

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

9. A device in accordance with claim 8, 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.

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

11. A device in accordance with claim 9, wherein non-metal elements of the dielectric grid are off-set above the metal elements of the wire grid layer.

12. A device in accordance with claim 1, wherein the elongated metal elements have lengths longer than a wavelength of visible light and a period less than half the wavelength of visible light.

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

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

a) a substrate with a refractive index;

b) at least one thin film layer, disposed on the substrate, the thin film layer having a refractive index greater than the refractive index of the substrate; and

c) a wire-grid layer, disposed over the at least one thin film layer, 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.

15. A device in accordance with claim 14, wherein the at least one thin film layer includes at least two thin film layers having different refractive indices with respect to one another.

16. A device in accordance with claim 14, wherein the at least one thin film layer includes at least three thin film layers.

17. A device in accordance with claim 14, wherein the at least one thin film layer extends continuously across the substrate.

18. A device in accordance with claim 14, wherein the at least one thin film layer is formed of 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; and

zirconium dioxide.

19. A device in accordance with claim 14, wherein the at least one 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.

20. A device in accordance with claim 19, wherein non-metal elements of the dielectric grid are aligned below the metal elements of the wire grid layer.

21. A device in accordance with claim 19, wherein non-metal elements of the dielectric grid are off-set below the metal elements of the wire grid layer.

22. A device in accordance with claim 14, further comprising:

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

23. A device in accordance with claim 22, 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.

24. A device in accordance with claim 23, wherein non-metal elements of the dielectric grid are aligned above the metal elements of the wire grid layer.

25. A device in accordance with claim 23, wherein non-metal elements of the dielectric grid are off-set above the metal elements of the wire grid layer.

26. A device in accordance with claim 14, wherein the elongated metal elements have lengths longer than a wavelength of visible light and a period less than half the wavelength of visible light.

27. A device in accordance with claim 14, wherein the elongated metal elements include alternating layers of metal and non-metal materials.

28. 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;

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

d) at least one thin film layer, disposed between the wire-grid layer and the dielectric layer.

29. A device in accordance with claim 28, wherein the non-metal and metal elements of the arrays are oriented substantially parallel with one another, and the arrays having substantially equal periods.

30. A device in accordance with claim 29, wherein non-metal elements of the dielectric grid are aligned above the metal elements of the wire grid layer.

31. A device in accordance with claim 29, wherein non-metal elements of the dielectric grid are off-set above the metal elements of the wire grid layer.

32. A device in accordance with claim 28, further comprising:

at least one thin film layer, disposed between the substrate and the wire-grid layer.

33. A device in accordance with claim 32, wherein the at least one thin film layer includes a plurality of thin film layers with different refractive indices with respect to one another.

34. A device in accordance with claim 32, wherein at least one of the thin film layers between the substrate and the wire-grid layer has a refractive index greater than a refractive index of the substrate.

35. A device in accordance with claim 32, wherein the at least one thin film layer extends continuously across the substrate.

36. A device in accordance with claim 32, wherein the at least one thin film layer is formed of 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; and

zirconium dioxide.

37. A device in accordance with claim 32, wherein the at least one 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.

38. A device in accordance with claim 37, wherein non-metal elements of the dielectric grid are aligned below the metal elements of the wire grid layer.

39. A device in accordance with claim 37, wherein non-metal elements of the dielectric grid are off-set below the metal elements of the wire grid layer.

40. A device in accordance with claim 28, further comprising:

at least one other thin film layer, disposed over the dielectric layer.

41. A device in accordance with claim 28, wherein the elongated metal elements have lengths longer than a wavelength of visible light and a period less than half the wavelength of visible light.

42. A device in accordance with claim 28, wherein the elongated metal elements include alternating layers of metal and non-metal materials.

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

a) a substrate;

b) a stack of thin film layers, disposed over the substrate, and extending continuously across the substrate;

c) at least one of the thin film layers being uniform in structure and material;

d) at least one of the thin film layers 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; and

e) at least one of the thin film layers including a dielectric array of non-metal elements.

44. A device in accordance with claim 43, wherein the non-metal and metal elements of the arrays are oriented substantially parallel with one another, and the arrays having substantially equal periods.

45. A device in accordance with claim 44, wherein non-metal elements of the dielectric grid are aligned below the metal elements of the wire grid layer.

46. A device in accordance with claim 44, wherein non-metal elements of the dielectric grid are off-set below the metal elements of the wire grid layer.

47. A device in accordance with claim 43, further comprising:

at least one thin film layer, disposed between the substrate and the wire-grid layer.

48. A device in accordance with claim 47, wherein the at least one thin film layer includes a plurality of thin film layers with different refractive indices with respect to one another.

49. A device in accordance with claim 47, wherein at least one of the thin film layers between the substrate and the wire-grid layer has a refractive index greater than a refractive index of the substrate.

50. A device in accordance with claim 47, wherein the at least one thin film layer extends continuously across the substrate.

51. A device in accordance with claim 47, wherein the at least one thin film layer is formed of 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; and

zirconium dioxide.

52. A device in accordance with claim 47, wherein the at least one 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.

53. A device in accordance with claim 52, wherein non-metal elements of the dielectric grid are aligned below the metal elements of the wire grid layer.

54. A device in accordance with claim 52, wherein non-metal elements of the dielectric grid are off-set below the metal elements of the wire grid layer.

55. A device in accordance with claim 47, further comprising:

at least one other thin film layer, disposed over the dielectric layer.

56. A device in accordance with claim 44, wherein the elongated metal elements have lengths longer than a wavelength of visible light and a period less than half the wavelength of visible light.

57. A device in accordance with claim 43, wherein the elongated metal elements include alternating layers of metal and non-metal materials.