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

• US 7,813,039 B2
• Filed: 03/09/2009
• Issued: 10/12/2010
• Est. Priority Date: 12/06/2004
• Status: Expired due to Fees

• 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:
  US12/400,100
• Publication Number:
  US 20090168171A1
• Time in Patent Office: 582 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; and

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

d) 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, further comprising:

at least one continuous thin film layer disposed between the wire-grid layer and the substrate and extending between the gaps.

3. A device in accordance with claim 2, wherein the at least one continuous thin film layer comprises a plurality of continuous thin film layers with different refractive indices with respect to one another, disposed between the wire-grid layer and the substrate and extending between the gaps.

4. A device in accordance with claim 3, wherein at least one of the continuous thin film layers includes a dielectric grid including an array of non-metal elements.

5. A device in accordance with claim 2, further comprising at least one continuous thin film layer disposed over the plurality of adjacent dielectric-grid layers.

6. A device in accordance with claim 5, wherein the at least one continuous thin film layer disposed over the plurality of adjacent dielectric-grid layers comprises a plurality of continuous thin film layers with different refractive indices with respect to one another.

7. A device in accordance with claim 5, wherein the at least one continuous thin film layer disposed over the plurality of adjacent dielectric-grid layers includes a dielectric grid including an array of non-metal elements.

8. A device in accordance with claim 1, wherein the plurality of bordering dielectric-grid layers are formed of different materials.

9. A device in accordance with claim 1, wherein the plurality of bordering dielectric-grid layers have different indices of refraction.

10. A device in accordance with claim 9, wherein an index of refraction of a lower of the plurality of bordering dielectric-grid layers is less than an index of refraction of an upper of the plurality of bordering dielectric-grid layers.

11. A device in accordance with claim 1, wherein the plurality of bordering dielectric-grid layers are disposed directly on top of the wire-grid layer.

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; and

c) a plurality of contiguous dielectric-grid layers contiguous with one another, disposed directly on top of the wire-grid layer, each dielectric-grid layer including an array of non-metal elements, the plurality of contiguous dielectric-grid layers including different materials with different indices of refraction; and

d) 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, further comprising:

at least one continuous thin film layer disposed between the wire-grid layer and the substrate and extending between the gaps.

14. A device in accordance with claim 13, wherein the at least one continuous thin film layer comprises a plurality of continuous thin film layers with different refractive indices with respect to one another, disposed between the wire-grid layer and the substrate and extending between the gaps.

15. A device in accordance with claim 14, wherein at least one of the continuous thin film layers includes a dielectric grid including an array of non-metal elements.

16. A device in accordance with claim 12, wherein an index of refraction of a lower of the plurality of bordering dielectric-grid layers is less than an index of refraction of an upper of the plurality of bordering dielectric-grid layers.

17. 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; and

c) a plurality of bordering dielectric-grid layers bordering one another, disposed over the wire-grid layer, at least one of the dielectric-grid layers including an array of dielectric material elements; and

d) the array of dielectric material elements and the array of metal elements being oriented substantially parallel with one another, and the arrays having substantially equal periods.

18. A device in accordance with claim 17, further comprising:

at least one continuous thin film layer disposed between the wire-grid layer and the substrate and extending between the gaps.

19. A device in accordance with claim 18, wherein the at least one continuous thin film layer comprises a plurality of continuous thin film layers with different refractive indices with respect to one another, disposed between the wire-grid layer and the substrate and extending between the gaps.

20. A device in accordance with claim 19, wherein at least one of the continuous thin film layers includes a dielectric grid including an array of dielectric material elements.