High contrast inverse polarizer
An embedded, inverse wire-grid polarizer (WGP) includes ribs 13 located over a surface of a transparent substrate 11 , gaps 16 between the ribs 13 , and a fill-layer 15 substantially filling the gaps 16 . The fill-layer has a relatively high index of refraction, such as greater than 1.4. At a wavelength of light incident upon the WGP, E ∥ transmission can be greater than E ⊥ transmission. E ∥ is a polarization of light with an electric field oscillation parallel to a length L of the ribs, and E ⊥ is a polarization of light with an electric field oscillation perpendicular to a length L of the ribs. This embedded, inverse WGP is especially useful for polarizing, with high WGP performance, small wavelength (high-energy) regions of the electromagnetic spectrum (e.g. UV) which are difficult to polarize with conventional WGPs (E ⊥ transmission>E ∥ transmission).
1. An embedded, inverse wire-grid polarizer (WGP) comprising:
ribs located over a surface of a transparent substrate, gaps between the ribs, and a fill-layer substantially filling the gaps, the ribs being elongated and formed into an array;
at a wavelength of light incident upon the WGP in a range≥175 nm, E ∥ transmission>E ⊥ transmission, where E ∥ is a polarization of the light with an electric field oscillation parallel to a length of the ribs and E ⊥ is a polarization of the light with an electric field oscillation perpendicular to a length of the ribs;
the fill-layer having an index of refraction greater than 1.7 at the wavelength of the light; and
the fill-layer substantially fills the gaps and extends from the gaps over the ribs such that the fill-layer in each gap extends continuously over adjacent ribs to the fill-layer in each adjacent gap, the fill-layer extending over the ribs for a thickness of between 25 and 150 nanometers.
2. A method of using the WGP of claim 1 , comprising transmitting more E ∥ through the WGP than E ⊥ at the wavelength of light.
3. The WGP of claim 1 , wherein, at the wavelength of the light, the E ∥ transmission divided by the E ⊥ transmission is at least 1000.
4. The WGP of claim 1 , wherein the wavelength of light incident upon the WGP is in a range of 200-300 nm.
5. The WGP of claim 1 , wherein the index of refraction is greater than 1.8 at the wavelength of the light.
6. The WGP of claim 1 , wherein the index of refraction is greater than 2.0 at the wavelength of the light.
7. The WGP of claim 1 , wherein the fill layer comprises aluminum oxide.
8. The WGP of claim 1 , wherein a difference between a lower-rib-width and an upper-rib-width is greater than 20 nanometers, where lower-rib-width means a maximum width of the ribs in a lower-half of the rib closer to the substrate and upper-rib-width means a maximum width of the ribs in an upper-half of the rib farther from the substrate.
9. The WGP of claim 1 , wherein the fill-layer comprises aluminum oxide, zirconium oxide, hafnium oxide, silicon nitride, tantalum oxide, tellurium oxide, germanium oxide, a transition metal oxides, a rare earth oxide, or combinations thereof.
10. An embedded, inverse wire-grid polarizer (WGP) comprising:
ribs located over a surface of a transparent substrate, gaps between the ribs, and fill-layer substantially filling the gaps, the ribs being elongated and formed into an array;
at a wavelength of light incident upon the WGP in a range≥175 nm, E ∥ transmission>E ⊥ transmission, where E ∥ is a polarization of the light with an electric field oscillation parallel to a length of the ribs and E ⊥ is a polarization of the light with an electric field oscillation perpendicular to a length of the ribs;
the fill-layer having an index of refraction greater than 1.7 at the wavelength of the light; and
the fill-layer extends over the ribs for a thickness of between 60 and 90 nanometers.
11. The WGP of claim 10 , wherein the fill-layer comprises aluminum oxide, zirconium oxide, hafnium oxide, or combinations thereof.
12. The WGP of claim 10 , wherein the E ∥ transmission divided by the E ⊥ transmission is at least 300.
13. The WGP of claim 10 , wherein the fill layer comprises aluminum oxide.
14. The WGP of claim 10 , wherein a difference between a lower-rib-width and an upper-rib-width is greater than 20 nanometers, where lower-rib-width means a maximum width of the ribs in a lower-half of the rib closer to the substrate and upper-rib-width means a maximum width of the ribs in an upper-half of the rib farther from the substrate.
15. An embedded, inverse wire-grid polarizer (WGP) comprising:
ribs located over a surface of a transparent substrate, gaps between the ribs, and a fill-layer substantially filling the gaps, the ribs being elongated and formed into an array;
at a wavelength of light incident upon the WGP in a range≥175 nm, E ∥ transmission>E ⊥ transmission, where E ∥ is a polarization of the light with an electric field oscillation parallel to a length of the ribs and E ⊥ is a polarization of the light with an electric field oscillation perpendicular to a length of the ribs;
the fill-layer having an index of refraction greater than 1.7 at the wavelength of the light; and
a difference between a lower-rib-width and an upper-rib-width is greater than 10 nanometers, where lower-rib-width means a maximum width of the ribs in a lower-half of the rib closer to the substrate and upper-rib-width means a maximum width of the ribs in an upper-half of the rib farther from the substrate.
16. The WGP of claim 15 , wherein the difference between the lower-rib-width and the upper-rib-width is greater than 20 nanometers.
17. The WGP of claim 15 , wherein the fill layer comprises aluminum oxide.
18. The WGP of claim 15 , wherein the fill-layer comprises aluminum oxide, zirconium oxide, hafnium oxide, or combinations thereof.
19. The WGP of claim 15 , wherein the index of refraction is greater than 1.8 at the wavelength of the light.
20. The WGP of claim 15 , wherein, at the wavelength of the light, the E ∥ transmission divided by the E ⊥ transmission is at least 1000.