Fine pitch grid polarizer

• US 8,913,321 B2
• Filed: 09/27/2012
• Issued: 12/16/2014
• Est. Priority Date: 09/21/2010
• Status: Active Grant

• Current Assignee: Moxtek (Polatechno Co.,Ltd.)
• Original Assignee: Moxtek (Polatechno Co.,Ltd.)
• Inventors: Davis, Mark Alan
• Primary Examiner(s): FONT, FRANK G
• Application Number:
  US13/628,909
• Publication Number:
  US 20130258471A1
• Time in Patent Office: 810 Days
• Field of Search: 359/485.05, 359/487.03
• US Class Current: 359/485.05
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 5/3058 comprising electrically conductive elements, e.g. wire grids, conductive particles

Abstract

A grid polarizer including an array of groups of parallel elongated ribs disposed over a substrate. Each group of elongated ribs can comprise at least four ribs. Tops of two center ribs, at a center of each group, can be substantially the same elevational height and can be higher by more than 10 nm than tops of outer ribs of the groups. A region between adjacent ribs can have an index of refraction substantially equal to one. Some or all of the ribs can comprise polarizing wires disposed over substrate rods.

Claims

1. A grid polarizer, comprising:

an array of groups of parallel elongated ribs disposed over a substrate, each group of elongated ribs including at least four ribs;

a region between adjacent ribs in each group having an index of refraction substantially equal to one; and

tops of two inner ribs of each group are substantially the same elevational height and are higher by more than 10 nm than tops of outer ribs of the respective group.

2. The grid polarizer of claim 1, wherein:

each group of elongated ribs comprises at least six ribs and the ribs are arranged in stepped pyramidal cross-sectional shape such that a top of each interior rib is at least 10 nm higher than a top of an adjacent outer rib; and

each rib is paired with another rib of substantially the same elevational height on an opposite side of the pyramidal cross-sectional shape.

3. The grid polarizer of claim 2, wherein four innermost ribs of each group comprise polarizing wires disposed over substrate rods and two outermost ribs comprise polarizing wires not disposed over substrate rods.

4. The grid polarizer of claim 1, wherein a thickness of polarizing wires of the two inner ribs differs by at least 10 nanometers from a thickness of polarizing wires of two adjacent, outer ribs.

5. The grid polarizer of claim 1, wherein:

outermost ribs of each group comprise a material different than a material of inner ribs; and

the outermost ribs comprise an etch redeposition material.

6. The grid polarizer of claim 1, wherein all ribs comprise polarizing wires disposed over substrate rods.

7. The grid polarizer of claim 1, wherein a distance between the outermost ribs in each group is less than 200 nanometers.

8. The grid polarizer of claim 1, wherein a maximum distance between any two adjacent ribs in the groups is less than 40 nm.

9. The grid polarizer of claim 1, wherein interior ribs of the groups are at least 30 nm higher than adjacent outer ribs.

10. The grid polarizer of claim 1, wherein the ribs comprise:

polarizing bars disposed on opposite sides of a central, transparent, core;

each polarizing bar on one side is physically separate from a polarizing bar on an opposite side; and

each polarizing bar is physically separate from a polarizing bar on an adjacent rib.

11. The grid polarizer of claim 1, wherein the region between adjacent ribs extends from a top of a lowest of the two adjacent ribs towards the substrate for a thickness of at least 30 nanometers.

12. The grid polarizer of claim 1, wherein a pitch of one group to another group is between 80 nanometers and 150 nanometers.

13. A grid polarizer, comprising:

an array of groups of parallel elongated ribs disposed over a substrate;

each group of elongated ribs comprises at least six ribs;

two inner ribs of each group are substantially the same elevational height;

at least four interior ribs comprise polarizing wires disposed over substrate rods;

the ribs are arranged in stepped pyramidal cross-sectional shape such that tops of the two inner ribs are highest, and tops of each outer rib is lower, by at least 20 nm, than an adjacent interior rib;

each rib is paired with another rib of substantially the same elevational height on an opposite side of the pyramidal cross-sectional shape; and

a distance between the outermost ribs in each group is less than 200 nanometers.

14. The grid polarizer of claim 13, wherein

the outermost ribs of each group comprise a material different than a material of inner ribs;

and

the outermost ribs comprise an etch redeposition material.