Wire Grid Polarizer Heat Sink

Patent metadata

Field	Value
Publication number	US-2018052270-A1
Application number	US-201715709127-A
Country	US
Kind code	A1
Filing date	Sep 19, 2017
Priority date	Aug 16, 2016
Publication date	Feb 22, 2018
Grant date	—

Abstract

A wire grid polarizer (WGP) can include a heat-dissipation layer. The heat-dissipation layer can enable the WGP to be able to endure high temperatures. The heat-dissipation layer can be located (a) over an array of wires and farther from a transparent substrate than the array of wires; or (b) between the array of wires and the transparent substrate. The heat-dissipation layer can be a continuous layer. The heat-dissipation layer can have a high electrical resistivity and a high coefficient of thermal conductivity.

First claim

What is claimed is:

1 . A wire grid polarizer (WGP) configured to polarize light incident thereon, the WGP comprising:
an array of wires over a face of a transparent substrate, with channels between adjacent wires; each of the wires including a reflective layer and an absorptive layer; sidewalls of each of the wires extending from the reflective layer to the absorptive layer uninterrupted by any continuous layer in a plane parallel to the face of the transparent substrate; and a heat-dissipation layer sandwiched between the array of wires and the transparent substrate, the heat-dissipation layer being a continuous layer having an electrical resistivity of greater than 10 6 Ω*cm and a coefficient of thermal conductivity of greater than 5 W/(m*K).

2 . The WGP of claim 1 , wherein:
the absorptive layer is sandwiched between the reflective layer and the transparent substrate; and the absorptive layer adjoins the heat-dissipation layer or the absorptive layer is separated from the heat-dissipation layer by material having thermal resistance for heat conduction of a unit area of less than 10 −8 K*m 2 /W.

3 . The WGP of claim 1 , wherein:
the reflective layer is sandwiched between the absorptive layer and the transparent substrate; and the reflective layer adjoins the heat-dissipation layer or the reflective layer is separated from the heat-dissipation layer by material having thermal resistance for heat conduction of a unit area of less than 10 −8 K*m 2 /W.

4 . A wire grid polarizer (WGP) configured to polarize light incident thereon, the WGP comprising:
an array of wires over a face of a transparent substrate, with channels between adjacent wires; each of the wires including a reflective layer and an absorptive layer; sidewalls of each of the wires extending from the reflective layer to the absorptive layer uninterrupted by any continuous layer in a plane parallel to the face of the transparent substrate; a heat-dissipation layer located over the array of wires farther from transparent substrate, the heat-dissipation layer being a continuous layer having an electrical resistivity of greater than 10 6 Ω*cm and a coefficient of thermal conductivity of greater than 5 W/(m*K).

5 . The WGP of claim 4 , wherein the absorptive layer is sandwiched between the reflective layer and the transparent substrate and the heat-dissipation layer adjoins the reflective layer.

6 . The WGP of claim 4 , further comprising an antireflection layer located over the heat-dissipation layer and farther from the transparent substrate than the heat-dissipation layer, the heat-dissipation layer being sandwiched between the antireflection layer and the array of wires.

7 . The WGP of claim 4 , wherein a volume of the heat-dissipation layer is at least three times greater than a volume of the absorptive layer.

8 . The WGP of claim 4 , wherein a thickness of the heat-dissipation layer, from a distal end of the array of wires farthest from transparent substrate, to an outermost surface of the heat-dissipation layer, is at least three times greater than a thickness of the absorptive layer, both thicknesses being measured perpendicular to the face of a transparent substrate.

9 . A wire grid polarizer (WGP) configured to polarize light incident thereon, the WGP comprising:
an array of wires over a face of a transparent substrate, with channels between adjacent wires; each of the wires including a reflective layer and an absorptive layer; a heat-dissipation layer located over the array of wires and farther from the transparent substrate than the array of wires or located between the array of wires and the transparent substrate; and the heat-dissipation layer being a continuous layer having an electrical resistivity of greater than 10 6 Ω*cm and a coefficient of thermal conductivity of greater than 5 W/(m*K).

10 . The WGP of claim 9 , wherein:
the absorptive layer is capable of generating heat from absorbed light; and the heat-dissipation layer is capable of conducting the heat generated in the absorptive layer away from the reflective layer.

11 . The WGP of claim 9 , wherein each of the channels extends from a proximal end of the array of wires closest to transparent substrate to a distal end of the array of wires farthest from transparent substrate.

12 . The WGP of claim 9 , wherein:
the absorptive layer is a first absorptive layer; each of the wires further comprises a second absorptive layer; the reflective layer is sandwiched between the first absorptive layer and the second absorptive layer; the heat-dissipation layer is a first heat-dissipation layer located over the array of wires and farther from transparent substrate; the WGP further comprises a second heat-dissipation layer located under the array of wires and closer to transparent substrate, the second heat-dissipation layer being a continuous layer having an electrical resistivity of greater than 10 6 Ω*cm and a coefficient of thermal conductivity of greater than 5 W/(m*K); and the array of wires is sandwiched between the first heat-dissipation layer and the second heat-dissipation layer with the first absorptive layer located closer to the first heat-dissipation layer and the second absorptive layer located closer to the second heat-dissipation layer.

13 . The WGP of claim 9 , wherein the heat-dissipation layer comprises at least 90% aluminum oxide.

14 . The WGP of claim 9 , wherein the coefficient of thermal conductivity of the heat-dissipation layer is greater than 15 W/(m*K).

15 . The WGP of claim 9 , wherein the heat-dissipation layer adjoins the reflective layer.

16 . The WGP of claim 9 , wherein:
the absorptive layer is located closer to the heat-dissipation layer than the reflective layer; each of the wires further comprises a thermal-insulating layer sandwiched between the reflective layer and the absorptive layer, the thermal-insulating layer having a coefficient of thermal conductivity of less than 4 W/(m*K).

17 . The WGP of claim 9 , wherein the heat-dissipation layer adjoins the absorptive layer.

18 . The WGP of claim 9 , wherein the heat-dissipation layer covers at least 90% of an exposed surface of the absorptive layer, the exposed surface of the absorptive layer being any surface of the absorptive layer not in direct contact with the transparent substrate or material of the array of wires.

19 . The WGP of claim 9 , wherein the absorptive layer is sandwiched between the reflective layer and the heat-dissipation layer and the heat-dissipation layer extends into the channels and along sides of the absorptive layer to directly contact the reflective layer.

20 . The WGP of claim 9 , further comprising:
a heat sink coupled to the heat-dissipation layer capable of conducting heat away from the heat-dissipation layer, and thus away from the array of wires; and the heat sink being located outside of the array of wires.

Assignees

• Moxtek Inc

Inventors

• Nielson R Stewart
• Ogden Shaun
• Free Mathew
• Williams Bradley R
• Lane Fred
• Wangensteen Ted

Classifications

• G02B5/3033

  in the form of a thin sheet or foil, e.g. Polaroid · CPC title

• G02B7/008

  with means for compensating for changes in temperature or for controlling the temperature; thermal stabilisation · CPC title

• G02B5/3058 Primary

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

• G02B5/3025

  Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state (G02B5/3008, G02B5/3016 take precedence) · CPC title

• G02F1/133548

  Wire-grid polarisers · CPC title