Overcoat Wire Grid Polarizer

Patent metadata

Field	Value
Publication number	US-2018052257-A1
Application number	US-201715691315-A
Country	US
Kind code	A1
Filing date	Aug 30, 2017
Priority date	Aug 16, 2016
Publication date	Feb 22, 2018
Grant date	—

Abstract

A wire grid polarizer (WGP) can be durable and have high performance. The WGP can comprise an array of wires 13 on a substrate 11. An overcoat layer 32 can be located at distal ends of the array of wires 13 and can span channels 15 between the wires 13. A conformal-coat layer 61 can coat sides 13 s and distal ends 13 d of the wires 13 between the wires 13 and the overcoat layer 32. The overcoat layer can comprise aluminum oxide. An antireflection layer 33 can be located over the overcoat layer 32.

First claim

What is claimed is:

1 . A wire grid polarizer (WGP) comprising:
an array of wires located over a face of a transparent substrate, the array of wires being substantially-parallel and elongated, with channels between adjacent wires; each wire of the array of wires having a cross-sectional profile with a base located closest to the substrate and a distal end located farthest from the substrate; and opposite sides facing the channels on opposite sides of the wire, respectively, and extending from the base to the distal end; an overcoat layer located at the distal ends of the array of wires and spanning the channels; and a conformal-coat layer including a moisture-barrier layer that coats the sides of the wires and the distal ends of the wires between the wires and the overcoat layer.

2 . The WGP of claim 1 , wherein the conformal-coat layer further comprises a layer of aluminum oxide, distinct from the wires, located between the moisture-barrier layer and the wires.

3 . The WGP of claim 1 , further comprising an antireflection layer located over the overcoat layer.

4 . The WGP of claim 1 , wherein the overcoat layer comprises aluminum oxide.

5 . The WGP of claim 1 , further comprising an antireflection layer located over the overcoat layer and wherein the overcoat layer comprises aluminum oxide.

6 . The WGP of claim 1 , wherein the WGP can withstand a durability test of 168 hours at 300° C., immediately after manufacturing, with less than 0.005 percent increase of Ts.

7 . The WGP of claim 1 , wherein the WGP can withstand a durability test of 168 hours at 300° C., immediately after manufacturing, with less than 0.5% degradation of Rs.

8 . The WGP of claim 1 , wherein the WGP forms part of an image projector, the image projector comprising:
a light source capable of emitting a beam of light; a spatial light modulator: located to receive at least part of the beam of light; and having a plurality of pixels, each pixel capable of receiving a signal and transmitting at least part of the beam of light without causing a change in polarization, or rotating a polarization of at least part of the beam of light, based on the signal; the WGP located in at least part of the beam of light prior to entering the spatial light modulator, after exiting the spatial light modulator, or both.

9 . A wire grid polarizer (WGP) comprising:
an array of wires located over a face of a transparent substrate, the array of wires being substantially-parallel and elongated, with channels between adjacent wires; each wire of the array of wires having: a cross-sectional profile with a base located closest to the substrate and a distal end located farthest from the substrate; and opposite sides facing the channels on opposite sides of the wire, respectively, and extending from the base to the distal end; an overcoat layer located at the distal ends of the array of wires and spanning the channels; and an antireflection layer located over the overcoat layer.

10 . The WGP of claim 9 , wherein the overcoat layer comprises aluminum oxide.

11 . The WGP of claim 9 , wherein the WGP forms part of an image projector, the image projector comprising:
a light source capable of emitting a beam of light; a spatial light modulator: located to receive at least part of the beam of light; and having a plurality of pixels, each pixel capable of receiving a signal and transmitting at least part of the beam of light without causing a change in polarization, or rotating a polarization of at least part of the beam of light, based on the signal; and the WGP located in at least part of the beam of light prior to entering the spatial light modulator, after exiting the spatial light modulator, or both.

12 . The WGP of claim 9 , wherein the WGP can withstand a durability test of 168 hours at 300° C., immediately after manufacturing, with an average of less than 0.005 percent increase of Ts across 100 WGPs.

13 . The WGP of claim 9 , wherein the WGP can withstand a durability test of 168 hours at 300° C., immediately after manufacturing, with an average of less than 0.5% degradation of Rs across 100 WGPs.

14 . A wire grid polarizer (WGP) comprising:
an array of wires located over a face of a transparent substrate, the array of wires being substantially-parallel and elongated, with channels between adjacent wires; each wire of the array of wires having: a cross-sectional profile with a base located closest to the substrate and a distal end located farthest from the substrate; and opposite sides facing the channels on opposite sides of the wire, respectively, and extending from the base to the distal end; and an overcoat layer located at the distal ends of the array of wires and spanning the channels, the overcoat layer comprising aluminum oxide.

15 . The WGP of claim 14 , wherein:
the overcoat layer extends down the sides of the wires from the distal end to the base including a thickness of between 10 and 100 nanometers; and the channels are air-filled.

16 . The WGP of claim 14 , wherein the WGP can withstand a durability test of 168 hours at 300° C., immediately after manufacturing, with less than 0.005 percent increase of Ts.

17 . The WGP of claim 14 , wherein the WGP can withstand a durability test of 168 hours at 300° C., immediately after manufacturing, with less than 0.5% degradation of Rs.

18 . A method of manufacturing a wire grid polarizer (WGP), the method comprising the following steps in the following order:
providing an array of wires located over a face of a transparent substrate, the array of wires being substantially-parallel and elongated, with channels between adjacent wires, wherein: the channels are air-filled; each wire of the array of wires has a cross-sectional profile with a base located closest to the substrate and a distal end located farthest from the substrate; and each wire of the array of wires has opposite sides facing the channels on opposite sides of the wire, respectively, and extending from the base to the distal end; applying a moisture-barrier layer to the sides and to the distal ends of the wires while maintaining the channels air-filled; and applying an overcoat layer, over the moisture-barrier layer, at the distal ends of the array of wires, and spanning the channels and maintaining the channels air-filled.

19 . The method of claim 18 , further comprising applying an antireflection layer over the overcoat layer.

20 . The method of claim 18 , wherein Tp 1 -Tp 2 <1.5%, where the subscript 1 refers to performance before applying the overcoat layer and subscript 2 refers to performance after applying the antireflection layer.

Assignees

• Moxtek Inc

Inventors

• Nielson R Stewart
• Williams Bradley R
• Free Mathew
• Wangensteen Ted

Classifications

• G02B1/04

  made of organic materials, e.g. plastics (G02B1/08 takes precedence) · CPC title

• C09D1/00

  Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances · CPC title

• G02B5/3058

  comprising electrically conductive elements, e.g. wire grids, conductive particles · CPC title

• G02B1/115

  Multilayers · CPC title

• G02B1/18 Primary

  Coatings for keeping optical surfaces clean, e.g. hydrophobic or photo-catalytic films (G02B1/16 takes precedence) · CPC title