Optical retarders and methods of making the same
In one aspect, the disclosure features an article that includes a first layer having spaced-apart rows of a first material, and a second layer supported by the first layer, the second layer having spaced-apart rows of a second material. The rows of the first layer extend along a first direction and the rows of the second layer extend along a second direction non-parallel with the first direction and each layer is independently birefringent for light of a wavelength λ propagating along an axis that intersects the first and second layers, where λ is in a range from about 150 nm to about 5,000 nm.
1 . An article, comprising:
a first layer comprising spaced-apart rows of a first material, and
a second layer supported by the first layer, the second layer comprising spaced-apart rows of a second material,
wherein the rows of the first layer extend along a first direction and the rows of the second layer extend along a second direction non-parallel with the first direction and each layer is independently birefringent for light of a wavelength λ propagating along an axis that intersects the first and second layers, where λ is in a range from about 150 nm to about 5,000 nm.
2 . The article of claim 1 , wherein the first and second materials are different.
3 . The article of claim 1 , wherein at least one of the first and second materials is a dielectric material.
4 . The article of claim 1 , wherein at least one of the first and second materials is a dielectric material selected from a group consisting of SiO 2 , SiN x , Si, Al 2 O 3 , ZrO 2 , Ta 2 O 5 , TiO 2 , HfO 2 , Nb 2 O 5 , and MgF 2 .
5 . The article of claim 1 , wherein at least one of the first and second materials is a nanolaminate material.
6 . The article of claim 5 , wherein at least one of the first and second materials is a nanolaminate material comprising one or more materials selected from a group consisting of SiO 2 , SiN x , Si, Al 2 O 3 , ZrO 2 , Ta 2 O 5 , TiO 2 , HfO 2 , Nb 2 O 5 , and MgF 2 .
7 . The article of claim 1 , further comprising a third layer supported by the second layer and comprising spaced-apart rows of a third material extending along a third direction that is non-parallel with at least one of the first and second directions and wherein the third layer is birefringent for light of wavelength λ propagating along an axis that intersects the first, second, and third layers.
8 . The article of claim 7 , wherein the third direction of the rows of the third material is parallel with one of the first and second directions.
9 . The article of claim 7 , wherein the third direction of the rows of the third material is non-parallel with both of the first and second directions.
10 . The article of claim 7 , wherein at least one of the first, second, and third materials comprises a dielectric material selected from a group consisting of SiO 2 , SiN x , Si, Al 2 O 3 , ZrO 2 , Ta 2 O 5 , TiO 2 , HfO 2 , Nb 2 O 5 , and MgF 2 .
11 . The article of claim 10 , wherein each of the first, second, and third materials is a nanolaminate material independently selected from the group consisting of SiO 2 , SiN x , Si, Al 2 O 3 , ZrO 2 , Ta 2 O 5 , TiO 2 , HfO 2 , Nb 2 O 5 , and MgF 2 .
12 . The article of claim 1 , wherein the first layer further comprises rows of a third material alternating with the spaced-apart rows of the first material and extending along the first direction, the third material being different from the first material.
13 . The article of claim 12 , wherein the third material defines a substrate, the rows of the third material are defined by walls of trenches within the substrate, and the first material is disposed within the trenches.
14 . The article of claim 12 , wherein the first and third materials are dielectric materials.
15 . The article of claim 13 , wherein the first material is selected from the group consisting of SiO 2 , SiN x , Si, Al 2 O 3 , ZrO 2 , Ta 2 O 5 , TiO 2 , HfO 2 , Nb 2 O 5 , and MgF 2 .
16 . The article of claim 15 , wherein the first material is a nanolaminate material.
17 . The article of claim 13 , further comprising a layer of the first material disposed between the rows of the first layer and the rows of the second layer.
18 . The article of claim 17 , wherein the layer of the first material is contiguous with the rows of the first material of the first layer.
19 . The article of claim 18 , further comprising an antireflection film disposed between the layer of the first material and the rows of the second material of the second layer.
20 . The article of claim 13 , wherein the second layer further comprises rows of a fourth material alternating with the spaced-apart rows of the second material and extending along the second direction, the fourth material being different from the second material.
21 . The article of claim 20 , wherein the fourth material defines a substrate, the rows of the fourth material are defined by walls of trenches within the substrate, and the second material is disposed within the trenches.
22 . The article of claim 20 , wherein the second and fourth materials are dielectric materials.
23 . The article of claim 21 , wherein the first material and second materials comprise one or more materials selected from the group consisting of SiO 2 , SiN x , Si, Al 2 O 3 , ZrO 2 , Ta 2 O 5 , TiO 2 , HfO 2 , Nb 2 O 5 , and MgF 2 .
24 . The article of claim 1 , wherein an angle between the first and second directions is at least about 10°.
25 - 27 . (canceled)
28 . The article of claim 1 , wherein an angle between the first and second directions is about 80° or less.
29 . (canceled)
30 . The article of claim 1 , wherein the first layer is a monolithic layer.
31 . (canceled)
32 . The article of claim 30 , wherein the second layer is a monolithic layer.
33 . The article of claim 1 , further comprising an antireflection film disposed between the first and second layers.
34 . The article of claim 1 , wherein the first and second layers each independently have an optical retardation of at least about 1 nm for light of the wavelength λ.
35 - 39 . (canceled)
40 . The article of claim 1 , wherein one of the first and second layers has an optical retardation that is greater than the optical retardation of the other layer, a difference between the optical retardations of the first and second layers is at least about 1 nm for light of the wavelength λ.
41 - 42 . (canceled)
43 . The article of claim 1 , wherein a combined thickness of the first and second layers is about 9 microns or less.
44 - 45 . (canceled)
46 . The article of claim 43 , wherein the first and second layers each independently have a thickness of about 5 microns or less.
47 - 48 . (canceled)
49 . The article of claim 1 , wherein centers of successive rows of the first layer are spaced apart by about 400 nm or less.
50 - 57 . (canceled)
58 . The article of claim 1 , wherein the article retards incident radiation at wavelengths λ 1 and λ 2 by respective amounts Γ 1 and Γ 2 , where |λ 1 −λ 2 | is at least about 15 nm, Γ 1 and Γ 2 are substantially equal, and both λ 1 and λ 2 are in a range from about 150 nm to about 5,000 nm.
59 - 65 . (canceled)
66 . A system, comprising:
the article of claim 58 , and
a polarizer,
wherein the article and polarizer are configured so that during operation the polarizer substantially polarizes radiation of wavelengths λ 1 and λ 2 prior to the radiation being received by the article.
67 . The system of claim 66 , wherein the article transmits radiation received by the article and the system further comprises a second polarizer configured so that during operation the second polarizer receives radiation after the radiation is transmitted by the article.
68 . A system, comprising:
the article of claim 1 , and
a polarizer,
wherein the article and polarizer are configured so that during operation the polarizer substantially polarizes radiation of a wavelength λ prior to the radiation being received by the article.
69 . The system of claim 68 , wherein the article transmits radiation received by the article and the system further comprises a second polarizer configured so that during operation the second polarizer receives radiation after the radiation is transmitted by the article.
70 . An article, comprising:
a first layer comprising spaced-apart rows of a first material, centers of adjacent rows of the first material being spaced apart by about 400 nm or less, and
a second layer supported by the first layer, the second layer comprising spaced-apart rows of a second material, centers of adjacent rows of the second material being spaced apart by about 400 nm or less;
wherein the rows of the first layer extend along a first direction and the rows of the second layer extend along a second direction non-parallel with the first direction.
71 - 95 . (canceled)
96 . A method, comprising:
forming a first layer comprising spaced-apart rows of a first material using atomic layer deposition, the rows of the first material extending along a first direction, and
disposing a second layer over first layer, the second layer comprising spaced-apart rows of a second material extending along a second direction non-parallel with the first direction.
97 - 104 . (canceled)