Ultra-thin, planar, plasmonic metadevices
An ultra-thin planar device is used for arbitrary waveform formation on a micrometer scale, regardless of the incident light's polarization. Patterned perforations are made in a 30 nm-thick metal film, creating discrete phase shifts and forming a desired wavefront of cross-polarized, scattered light. The signal-to-noise ratio of these devices is at least one order of magnitude higher than current metallic nano-antenna designs. The focal length of a lens built on such principle can also be adjusted by changing the wavelength of the incident light. All proposed embodiments can be embedded, for example, on a chip or at the end of an optical fiber.
1. A method of making a planar plasmonic device, wherein the method comprises:
forming a plurality of nanovoids in a subwavelength-thick film, wherein said nanovoids form a pattern, and wherein a shape of each nanovoid provides a change of phase and magnitude of an incoming radiation due to plasmonic resonance of the radiation coupled to this nanovoid, wherein the shape of each nanovoid is configured to provide individual resonance characteristics, wherein the shape of the each nanovoid of the plurality of nanovoids is configured to provide a given phase front of outcoming radiation which is combined from portions of radiation exiting all nanovoids in said film, wherein a distribution of the plurality of nanovoids are configured to form a visible holographic image of an object.
2. The method of claim 1 , wherein each nanovoid is in the form of a v-shape.
3. The method of claim 1 , wherein each nanovoid is in the form of a curved shape.
4. The method of claim 1 , wherein each nanovoid is in the form of a linear shape.
5. The method of claim 1 , wherein said subwavelength-thick film comprises a gold film.
6. The method of claim 1 , wherein said subwavelength-thick film comprises an aluminum film.
7. The method of claim 1 , wherein said subwavelength-thick film comprises a silver film.
8. The method of claim 1 , wherein said subwavelength-thick film comprises a single layer or multilayer graphene.
9. The method of claim 1 , wherein said subwavelength-thick film comprises silicon carbide.
10. The method of claim 1 , wherein the outcoming radiation forms a waveform similar to an output of a conventional lens.
11. The method of claim 10 , wherein the device is operating as a focusing lens, and a focal length of the lens is controlled by adjustment of a wavelength of the incident light.
12. The method of claim 11 , wherein the focal length of the device is in the order of one micrometer.
13. The method of claim 1 , wherein the subwavelength-thick film is from 10 to 50 nm thick.
14. A method of making a planar plasmonic device, wherein the method comprises:
forming a plurality of nanovoids perforated in a subwavelength-thick film, wherein said nanovoids form a pattern, and wherein a shape of each nanovoid provides a change of phase and magnitude of an incoming radiation due to plasmonic resonance of the radiation coupled to this nanovoid, wherein the shape of each nanovoid is configured to provide individual resonance characteristics, wherein the shape of the each nanovoid of the plurality of nanovoids is configured to provide a given phase front of outcoming radiation which is combined from portions of radiation exiting all nanovoids in said film, wherein a distribution of the plurality of nanovoids are configured to form a visible holographic image of an object.
15. The method of claim 14 , wherein the subwavelength-thick film is from 10 to 50 nm thick.
16. The method of claim 14 , wherein each nanovoid is in the form of a curved shape.
17. The method of claim 14 , wherein each nanovoid is in the form of a linear shape.
18. The method of claim 14 , wherein said subwavelength-thick film comprises a gold film.
19. A method of making a planar plasmonic device, wherein the method comprises:
forming a plurality of nanovoids perforated in a subwavelength-thick film, wherein said nanovoids form a pattern, and wherein a shape of each nanovoid provides a change of phase and magnitude of an incoming radiation due to plasmonic resonance of the radiation coupled to this nanovoid, wherein the shape of each nanovoid is configured to provide individual resonance characteristics, wherein the shape of the each nanovoid of the plurality of nanovoids is configured to provide a given phase front of outcoming radiation which is combined from portions of radiation exiting all nanovoids in said film.
20. The method of claim 19 , wherein the subwavelength-thick film is from 10 to 50 nm thick.