Universal broadband polarizer, devices incorporating same, and method of making same
View Patent ↗A polarization dependent device suitable for effecting at least one polarization of a broadband portion of electromagnetic radiation incident upon the device includes a substrate, and a plurality of regions of differing refractive indices positioned in an alternating manner and substantially adjacent to the substrate to effect the at least one polarization impinging on the regions. The plurality of regions are oriented with respect to the at least one polarization of the broadband portion of the electromagnetic radiation so as to effect the at least one polarization of the broadband portion of the electromagnetic radiation impinging on the regions.
1. A polarization dependent device, said device comprising:
a substrate;
a plurality of regions of differing refractive indices positioned in an alternating manner and substantially adjacent to said substrate, said plurality of regions comprising a plurality of spaced-apart strips of a first material extending along a common direction, each strip comprising a top surface distal from said substrate and a pair of sidewalls extending between the substrate and the top surface; and,
a continuous dielectric layer conformally covering the top surface and sidewalls of the spaced-apart strips, where the dielectric layer has a uniform thickness in a range from 1 nm to 50 nm,
wherein the polarization dependent device is a polarizer for incident light at at least one wavelength in a range from 300 nm to 1600 nm.
2. The device of claim 1 , wherein said device effects the at least one polarization of broadband electromagnetic radiation incident upon the device by at least one of beamsplitting, beam combining, absorbing and reflecting the radiation at the at least one wavelength.
3. The device of claim 1 , wherein said device has an extinction ratio greater than approximately 100 in transmission over a wavelength range of 390 nm to 1650 nm.
4. The device of claim 1 , wherein said device has a transmittance greater than 0.50 over a wavelength range of 390 nm to 1650 nm.
5. The device of claim 1 , further comprising at least one anti-reflection coating.
6. The device of claim 5 , wherein said at least one anti-reflection coating enhances transmission at the at least one wavelength by reducing unwanted reflections.
7. The device of claim 1 , wherein the conformal dielectric layer is a metal oxide.
8. The device of claim 1 , wherein the conformal dielectric layer is silicon dioxide, silicon nitride, silicon oxynitride, or magnesium fluoride.
9. The device of claim 1 , wherein the conformal dielectric layer is an organic polymer.
10. The device of claim 1 , wherein the strips have a width in a range from about 10 nm to 500 nm.
11. The device of claim 1 , wherein the strips have a width in a range from about 15 nm to 180 nm.
12. The device of claim 1 , wherein the strips have a height in a range from about 10 nm to 1,000 nm.
13. The device of claim 1 , wherein the strips have a height in a range from about 30 nm to 500 nm.
14. The device of claim 1 , where the strips are arranged as a grating having a period in a range between about 10 nm and 1,000 nm.
15. The device of claim 1 , where the strips are arranged as a grating having a period in a range between about 30 nm and 200 nm.
16. The device of claim 1 , where the strips are arranged as a grating having a period that is constant or varied or chirped.
17. A polarization dependent device suitable for effecting at least one polarization of broadband electromagnetic radiation incident upon the device, said device comprising:
a substrate;
a plurality of regions of differing refractive indices positioned in an alternating manner and substantially adjacent to said substrate to effect the at least one polarization impinging on said regions, said plurality of regions comprising a plurality of spaced-apart strips of a first material extending along a common direction, each strip comprising a top surface distal from said substrate and a pair of sidewalls extending between the substrate and the top surface;
at least one anti-reflection coating; and
a continuous dielectric layer conformally covering the top surface and sidewalls of the spaced-apart strips, where the dielectric layer has a uniform thickness in a range from 1 nm to 50 nm regions; and,
wherein said device has an extinction ratio greater than approximately 5000 in transmission over a wavelength range of 1250 nm to 1350 nm, and wherein said device has a transmittance greater than 0.96 over a wavelength range of 1250 nm to 1350 nm.
18. A polarization dependent device suitable for effecting at least one polarization of broadband electromagnetic radiation incident upon the device, said device comprising:
a substrate;
a plurality of regions of differing refractive indices positioned in an alternating manner and substantially adjacent to said substrate to effect the at least one polarization impinging on said regions, said plurality of regions comprising a plurality of spaced-apart strips of a first material extending along a common direction, each strip comprising a top surface distal from said substrate and a pair of sidewalls extending between the substrate and the top surface;
at least one anti-reflection coating; and
a continuous dielectric layer conformally covering the top surface and sidewalls of the spaced-apart strips, where the dielectric layer has a uniform thickness in a range from 1 nm to 50 nm,
wherein said device has an extinction ratio greater than approximately 5000 in transmission over a wavelength range of 1450 nm to 1650 nm, and wherein said device has a transmittance greater than 0.96 over a wavelength range of 1450 nm to 1650 nm.