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

Simulation results of the Selfoc lens, showing the amplitude of the y component of electric field (Ey).The incident frequencies are 35 THz (a)–(b) and 45 THz (c)–(d), respectively. In calculations, the lateral profile of h is the same as that in Fig. 3.
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f6: Simulation results of the Selfoc lens, showing the amplitude of the y component of electric field (Ey).The incident frequencies are 35 THz (a)–(b) and 45 THz (c)–(d), respectively. In calculations, the lateral profile of h is the same as that in Fig. 3.

Mentions: To validate the above analyses, the field distributions are performed for different incident frequencies by using FDTD method. As shown in Figs. 6 (a) and 6(c), when the frequencies of the incident point source are chosen as 35 THz and 45 THz, the excited GP waves can be transformed to be plane sources. Moreover, when plane sources with the frequencies of 35 THz and 45 THz are illuminated, the GP waves can be focused and transformed to be point sources as presented in Figs. 6(b) and 6(d). It can be concluded that even though the Selfoc lens is designed for 40 THz, it can still work well for other incident frequencies. In addition, the focal lengths for the incident frequencies of 35 THz and 45 THz are d1 = 963.1 nm and d2 = 963.5 nm, respectively. While for the frequency of 40 THz, the focal length is d0 = 963.2 nm. It is found that the focal lengths for these three incident frequencies are nearly unchanged, which confirms that the proposed Selfoc lens is dispersionless. This important characteristic ensures that the Selfoc lens possesses a wide operating frequency regime, which is necessary in practical applications. It should be noted that the pitch of graphene-based Selfoc lens is also a constant for different external voltages, which is discussed in the Supplementary Materials.


Graphene plasmonic lens for manipulating energy flow.

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

Simulation results of the Selfoc lens, showing the amplitude of the y component of electric field (Ey).The incident frequencies are 35 THz (a)–(b) and 45 THz (c)–(d), respectively. In calculations, the lateral profile of h is the same as that in Fig. 3.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f6: Simulation results of the Selfoc lens, showing the amplitude of the y component of electric field (Ey).The incident frequencies are 35 THz (a)–(b) and 45 THz (c)–(d), respectively. In calculations, the lateral profile of h is the same as that in Fig. 3.
Mentions: To validate the above analyses, the field distributions are performed for different incident frequencies by using FDTD method. As shown in Figs. 6 (a) and 6(c), when the frequencies of the incident point source are chosen as 35 THz and 45 THz, the excited GP waves can be transformed to be plane sources. Moreover, when plane sources with the frequencies of 35 THz and 45 THz are illuminated, the GP waves can be focused and transformed to be point sources as presented in Figs. 6(b) and 6(d). It can be concluded that even though the Selfoc lens is designed for 40 THz, it can still work well for other incident frequencies. In addition, the focal lengths for the incident frequencies of 35 THz and 45 THz are d1 = 963.1 nm and d2 = 963.5 nm, respectively. While for the frequency of 40 THz, the focal length is d0 = 963.2 nm. It is found that the focal lengths for these three incident frequencies are nearly unchanged, which confirms that the proposed Selfoc lens is dispersionless. This important characteristic ensures that the Selfoc lens possesses a wide operating frequency regime, which is necessary in practical applications. It should be noted that the pitch of graphene-based Selfoc lens is also a constant for different external voltages, which is discussed in the Supplementary Materials.

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