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Metallic nano-structures for polarization-independent multi-spectral filters.

Tang Y, Vlahovic B, Brady DJ - Nanoscale Res Lett (2011)

Bottom Line: Cross-shaped-hole arrays (CSHAs) are selected for diminishing the polarization-dependent transmission differences of incident plane waves.We investigate the light transmission spectrum of the CSHAs in a thin gold film over a wide range of features.It implicates the possibility to obtain a desired polarization-independent transmission spectrum from the CSHAs by designing their parameters.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Department of Physics, North Carolina Central University, Durham, NC, 27707, USA. tangy@nccu.edu.

ABSTRACT
Cross-shaped-hole arrays (CSHAs) are selected for diminishing the polarization-dependent transmission differences of incident plane waves. We investigate the light transmission spectrum of the CSHAs in a thin gold film over a wide range of features. It is observed that two well-separated and high transmission efficiency peaks could be obtained by designing the parameters in the CSHAs for both p-polarized and s-polarized waves; and a nice transmission band-pass is also observed by specific parameters of a CSHA too. It implicates the possibility to obtain a desired polarization-independent transmission spectrum from the CSHAs by designing their parameters. These findings provide potential applications of the metallic nano-structures in optical filters, optical band-pass, optical imaging, optical sensing, and biosensors.

No MeSH data available.


Related in: MedlinePlus

(a) Transmission spectrum of CSHA (L = 300 nm, W = 20 nm, period D = 350 nm, and h = 100 nm); (b) the electric field in the metal film of the TM wave; (c) the electric field in the metal film of the TE wave.
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Figure 3: (a) Transmission spectrum of CSHA (L = 300 nm, W = 20 nm, period D = 350 nm, and h = 100 nm); (b) the electric field in the metal film of the TM wave; (c) the electric field in the metal film of the TE wave.

Mentions: The metallic CSHAs are illuminated by a p-polarization (TM) monochromatic electromagnetic plane wave (electric field in the plane of the incidence), and an s-polarization (TE) monochromatic electromagnetic plane wave (electric field perpendicular to the plane of incidence), respectively. The simulations show that the TE and TM waves have same transmission spectrum (see Figure 3a) for the CSHAs. However, there is a difference in the electric field distributions of the TE and TM waves in the CSHA: more light is trapped in the horizontal rectangle open (hole) of the cross-shaped hole for TM wave (see Figure 3b), and more light is trapped in the vertical rectangle open of the cross-shaped hole for TE wave (see Figure 3c). These electric field distribution results verify that the efficiency of light coupling to SP is strongly polarization dependent; the shorter ridge of the hole has higher efficiency to induce SPs when the polarization of the light is parallel to it. Therefore, the CSHA is a good candidate for the polarization independent multi-spectral filters or FSS, since the CSHA provides a symmetrical structure for the TE and TM waves.


Metallic nano-structures for polarization-independent multi-spectral filters.

Tang Y, Vlahovic B, Brady DJ - Nanoscale Res Lett (2011)

(a) Transmission spectrum of CSHA (L = 300 nm, W = 20 nm, period D = 350 nm, and h = 100 nm); (b) the electric field in the metal film of the TM wave; (c) the electric field in the metal film of the TE wave.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211488&req=5

Figure 3: (a) Transmission spectrum of CSHA (L = 300 nm, W = 20 nm, period D = 350 nm, and h = 100 nm); (b) the electric field in the metal film of the TM wave; (c) the electric field in the metal film of the TE wave.
Mentions: The metallic CSHAs are illuminated by a p-polarization (TM) monochromatic electromagnetic plane wave (electric field in the plane of the incidence), and an s-polarization (TE) monochromatic electromagnetic plane wave (electric field perpendicular to the plane of incidence), respectively. The simulations show that the TE and TM waves have same transmission spectrum (see Figure 3a) for the CSHAs. However, there is a difference in the electric field distributions of the TE and TM waves in the CSHA: more light is trapped in the horizontal rectangle open (hole) of the cross-shaped hole for TM wave (see Figure 3b), and more light is trapped in the vertical rectangle open of the cross-shaped hole for TE wave (see Figure 3c). These electric field distribution results verify that the efficiency of light coupling to SP is strongly polarization dependent; the shorter ridge of the hole has higher efficiency to induce SPs when the polarization of the light is parallel to it. Therefore, the CSHA is a good candidate for the polarization independent multi-spectral filters or FSS, since the CSHA provides a symmetrical structure for the TE and TM waves.

Bottom Line: Cross-shaped-hole arrays (CSHAs) are selected for diminishing the polarization-dependent transmission differences of incident plane waves.We investigate the light transmission spectrum of the CSHAs in a thin gold film over a wide range of features.It implicates the possibility to obtain a desired polarization-independent transmission spectrum from the CSHAs by designing their parameters.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Department of Physics, North Carolina Central University, Durham, NC, 27707, USA. tangy@nccu.edu.

ABSTRACT
Cross-shaped-hole arrays (CSHAs) are selected for diminishing the polarization-dependent transmission differences of incident plane waves. We investigate the light transmission spectrum of the CSHAs in a thin gold film over a wide range of features. It is observed that two well-separated and high transmission efficiency peaks could be obtained by designing the parameters in the CSHAs for both p-polarized and s-polarized waves; and a nice transmission band-pass is also observed by specific parameters of a CSHA too. It implicates the possibility to obtain a desired polarization-independent transmission spectrum from the CSHAs by designing their parameters. These findings provide potential applications of the metallic nano-structures in optical filters, optical band-pass, optical imaging, optical sensing, and biosensors.

No MeSH data available.


Related in: MedlinePlus