Limits...
Graphene plasmonic lens for manipulating energy flow.

Wang G, Liu X, Lu H, Zeng C - Sci Rep (2014)

Bottom Line: Because photons are uncharged, it is still difficult to effectively control them by electrical means.It is found that the proposed lens can be utilized to focus and collimate the GP waves propagating along the graphene sheet.As an application of such a lens, the image transfer of two point sources with a separation of λ₀/30 is demonstrated.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China.

ABSTRACT
Manipulating the energy flow of light is at the heart of modern information and communication technologies. Because photons are uncharged, it is still difficult to effectively control them by electrical means. Here, we propose a graphene plasmonic (GP) lens to efficiently manipulate energy flow by elaborately designing the thickness of the dielectric spacer beneath the graphene sheet. Different from traditional metal-based lenses, the proposed graphene plasmonic lens possesses the advantages of tunability and excellent confinement of surface plasmons. It is found that the proposed lens can be utilized to focus and collimate the GP waves propagating along the graphene sheet. Particularly, the lens is dispersionless over a wide frequency range and the performance of lens can be flexibly tuned by adjusting the bias voltage. As an application of such a lens, the image transfer of two point sources with a separation of λ₀/30 is demonstrated.

No MeSH data available.


Related in: MedlinePlus

(a) Schematic diagram of the Selfoc lens. h represents the thickness of dielectric spacer. (b) Lateral profile of effective mode index and a representative case of transforming plane source to be point source in graphene (output intensity is shown in top figure).
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f1: (a) Schematic diagram of the Selfoc lens. h represents the thickness of dielectric spacer. (b) Lateral profile of effective mode index and a representative case of transforming plane source to be point source in graphene (output intensity is shown in top figure).

Mentions: As shown in Fig. 1, the proposed Selfoc lens consists of a monolayer graphene with chemical potential μc on top of a heavily doped silicon (Si) substrate separated by a dielectric spacer. The dielectric can be set as silicon dioxide with the relative permittivity of εr2 = 3.93132, and the thickness of the spacer h changes gradually from the position of z = 0 to periphery along the ± z-axis directions. The surrounding medium is assumed to be air and GP waves are excited and propagate along the +x-axis direction. A bias voltage is applied between the graphene sheet and doped Si substrate to change the doping of graphene by the electric-field effect1018.


Graphene plasmonic lens for manipulating energy flow.

Wang G, Liu X, Lu H, Zeng C - Sci Rep (2014)

(a) Schematic diagram of the Selfoc lens. h represents the thickness of dielectric spacer. (b) Lateral profile of effective mode index and a representative case of transforming plane source to be point source in graphene (output intensity is shown in top figure).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3921639&req=5

f1: (a) Schematic diagram of the Selfoc lens. h represents the thickness of dielectric spacer. (b) Lateral profile of effective mode index and a representative case of transforming plane source to be point source in graphene (output intensity is shown in top figure).
Mentions: As shown in Fig. 1, the proposed Selfoc lens consists of a monolayer graphene with chemical potential μc on top of a heavily doped silicon (Si) substrate separated by a dielectric spacer. The dielectric can be set as silicon dioxide with the relative permittivity of εr2 = 3.93132, and the thickness of the spacer h changes gradually from the position of z = 0 to periphery along the ± z-axis directions. The surrounding medium is assumed to be air and GP waves are excited and propagate along the +x-axis direction. A bias voltage is applied between the graphene sheet and doped Si substrate to change the doping of graphene by the electric-field effect1018.

Bottom Line: Because photons are uncharged, it is still difficult to effectively control them by electrical means.It is found that the proposed lens can be utilized to focus and collimate the GP waves propagating along the graphene sheet.As an application of such a lens, the image transfer of two point sources with a separation of λ₀/30 is demonstrated.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China.

ABSTRACT
Manipulating the energy flow of light is at the heart of modern information and communication technologies. Because photons are uncharged, it is still difficult to effectively control them by electrical means. Here, we propose a graphene plasmonic (GP) lens to efficiently manipulate energy flow by elaborately designing the thickness of the dielectric spacer beneath the graphene sheet. Different from traditional metal-based lenses, the proposed graphene plasmonic lens possesses the advantages of tunability and excellent confinement of surface plasmons. It is found that the proposed lens can be utilized to focus and collimate the GP waves propagating along the graphene sheet. Particularly, the lens is dispersionless over a wide frequency range and the performance of lens can be flexibly tuned by adjusting the bias voltage. As an application of such a lens, the image transfer of two point sources with a separation of λ₀/30 is demonstrated.

No MeSH data available.


Related in: MedlinePlus