Nano-optic refractive optics
A vertical dipole array structure includes a substrate that supports a film, which is not comprised of a negative-index metamaterial. The film includes a plurality of tilt-oriented portions and apertures. At least two of the tilt-oriented portions are separated by an aperture, and the tilt-oriented portions are configured such that incident radiation is redirected into a negative or positive refraction direction.
1. A vertical dipole array structure comprising (A) a substrate that supports (B) a film comprising a plurality of tilt-oriented portions, wherein (i) said film has a plurality of nanoapertures, (ii) at least two of said tilt-oriented portions are separated by a nanoaperture of the plurality of nanoapertures, (iii) said tilt-oriented portions are configured such that incident radiation is redirected into a negative refraction direction and through the plurality of nanoapertures, and (iv) said film is not comprised of a negative-index metamaterial, wherein the nanoapertures have a width of 40-80 nm,
wherein the tilt-oriented portions extend over vertical portions of the array structure such that sidewalls of adjacent tilt-oriented portions are parallel to each other, and the tilt-oriented portions each have a first sidewall and a second sidewall, the first sidewall being opposed in orientation to the second sidewall.
2. The vertical dipole array structure of claim 1 , wherein at least two of said tilt-oriented portions are separated by more than one nanoaperture.
3. The vertical dipole array structure of claim 1 , wherein the thin film comprises highly conducting material.
4. The vertical dipole array structure of claim 1 , wherein the thin film comprises Ag, Au, Al, Cu, Cr, graphene, graphite, or a conducting oxide.
5. The vertical dipole array structure of claim 1 , wherein the tilt-oriented portions are tilt-oriented at different angles relative to each other such that a diverging input beam is transmitted as a collimated parallel beam.
6. The vertical dipole array structure of claim 1 , wherein the tilt-oriented portions are tilt-oriented at angles such that incident radiation is transmitted through the nanoapertures constructively interferes at a focal point.
7. The vertical dipole array structure of claim 1 , wherein the nanoapertures are separated by uniform grating periods.
8. The vertical dipole array structure of claim 1 , wherein the nanoapertures are separated by non-uniform grating periods.
9. The vertical dipole array structure of claim 1 , wherein the tilt-oriented portions are configured to primarily support-1st order transmission of incident radiation.
10. The vertical dipole array structure of claim 1 , wherein a surface of the substrate that supports the film comprises a saw-tooth profile comprising tilt-oriented surfaces separated by at least one vertical-step surface.
11. The vertical dipole array structure of claim 1 , wherein a surface of the substrate that supports the film comprises a saw-tooth profile comprising a tilt-oriented surfaces separated by at least one vertical-step surface; and wherein the tilt-oriented surfaces are substantially parallel to each other.
12. The vertical dipole array structure of claim 1 , wherein the plurality of nanoapertures define discontinuities of the thin film.
13. The vertical dipole array structure of claim 1 , the substrate does not comprise a negative-index metamaterial.
14. The vertical dipole array structure of claim 1 , wherein the tilt-oriented portions can be adjusted to be tilt-oriented at different angles.
15. The vertical dipole array structure of claim 1 , wherein radiation is transmitted without a mirror-imaging effect.
16. The vertical dipole array structure of claim 1 , wherein radiation transmitted through the nanoapertures constructively interferes at a given spot for beam focusing function with spot size smaller than about 0.5λ.
17. The vertical dipole array structure of claim 1 , wherein the plurality of nanoapertures are structured to transmit a traverse magnetic polarization component and to block a transverse electric polarization component.
18. The vertical dipole array structure of claim 1 , wherein a width of each nanoaperture is 60 nm.
19. A vertical dipole array structure comprising (A) a substrate that supports (B) a film comprising a plurality of tilt-oriented portions,
wherein (i) said film has a plurality of nanoapertures, (ii) at least two of said tilt-oriented portions are separated by a nanoaperture of the plurality of nanoapertures, (iii) said tilt-oriented portions are configured such that incident radiation is transmitted through the plurality of nanoapertures and constructively interferes at a focal point, and (iv) said film is not comprised of a negative-index metamaterial, wherein the nanoapertures have a width of 40-80 nm, and
wherein the tilt-oriented portions extend over vertical portions of the array structure such that sidewalls of adjacent tilt-oriented portions are parallel to each other, and the tilt-oriented portions each have a first sidewall and a second sidewall, the first sidewall being opposed in orientation to the second sidewall.
20. A vertical dipole array structure comprising (A) substrate that supports (B) a film comprising a plurality of offset portions, wherein (i) said film has a plurality of nanoapertures, (ii) at least two of said offset portions are separated by a nanoaperture, (iii) said offset portions are configured such that incident radiation is redirected into an negative refraction direction and through the plurality of nanoapertures, and (iv) said film is not comprised of a negative-index metamaterial, wherein the nanoapertures have a width of 40-80 nm,
wherein the offset portions extend over vertical portions of the array structure such that sidewalls of adjacent offset portions are parallel to each other, and the offset portions each have a first sidewall and a second sidewall, the first sidewall being opposed in orientation to the second sidewall.
21. The vertical dipole array structure of claim 20 , wherein a surface of the substrate that supports the film comprises a mesa pattern.
22. A vertical dipole array structure comprising (A) a substrate that supports (B) a film comprising a plurality of tilt-oriented portions,
wherein (i) said film has a plurality of nanoapertures, (ii) at least two of said tilt-oriented portions are separated by a nanoaperture, (iii) said tilt-oriented portions are configured such that incident radiation is redirected into a positive or negative refraction direction and through the plurality of nanoapertures, and (iv) said film is not comprised of a negative-index metamaterial,
wherein the nanoapertures have a width of 40-80 nm,
wherein the vertical dipole array structure is arranged with the plurality of nanoapertures being oriented vertically with respect to the substrate such that the incident radiation is re-radiated into a direction tilted away from a direction normal to the substrate, and
wherein the tilt-oriented portions extend over vertical portions of the array structure such that sidewalls of adjacent tilt-oriented portions are parallel to each other, and the tilt-oriented portions each have a first sidewall and a second sidewall, the first sidewall being opposed in orientation to the second sidewall.
23. A vertical dipole array structure comprising (A) a substrate that supports (B) a film comprising a plurality of tilt-oriented portions, wherein (i) said film has a plurality of nanoapertures, (ii) at least two of said tilt-oriented portions are separated by a nanoaperture, (iii) said tilt-oriented portions are configured such that incident radiation is redirected only into a negative refraction direction and through the plurality of nanoapertures, and (iv) said film is not comprised of a negative-index metamaterial,
wherein the plurality of nanoapertures are structured to transmit a traverse magnetic polarization component and to block a transverse electric polarization component, and
wherein the tilt-oriented portions extend over vertical portions of the array structure such that sidewalls of adjacent tilt-oriented portions are parallel to each other, and the tilt-oriented portions each have a first sidewall and a second sidewall, the first sidewall being opposed in orientation to the second sidewall.