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Ultrasensitive optical absorption in graphene based on bound states in the continuum.

Zhang M, Zhang X - Sci Rep (2015)

Bottom Line: By taking suitable BICs, the selective absorption for S and P waves has not only been realized, but also all-angle absorption for the S and P waves at the same time has been demonstrated.We have also found that ultrasensitive strong absorptions can appear at any wavelength from mid-infrared to far-infrared band.These phenomena are very beneficial to biosensing, perfect filters and waveguides.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Beijing Normal University, Beijing 100875, China.

ABSTRACT
We have designed a sphere-graphene-slab structure so that the electromagnetic wave can be well confined in the graphene due to the formation of a bound state in a continuum (BIC) of radiation modes. Based on such a bound state, we have realized strong optical absorption in the monolayer graphene. Such a strong optical absorption exhibits many advantages. It is ultrasensitive to the wavelength because the Q factor of the absorption peak can be more than 2000. By taking suitable BICs, the selective absorption for S and P waves has not only been realized, but also all-angle absorption for the S and P waves at the same time has been demonstrated. We have also found that ultrasensitive strong absorptions can appear at any wavelength from mid-infrared to far-infrared band. These phenomena are very beneficial to biosensing, perfect filters and waveguides.

No MeSH data available.


The absorption peaks as a function of the wavelength λ and the incident angle θ.Here a = 5.5185 μm. The solid lines and circle dotted lines represent absorption peaks for the S wave and the P wave, respectively. The other parameters are identical with those in Fig. 1.
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f5: The absorption peaks as a function of the wavelength λ and the incident angle θ.Here a = 5.5185 μm. The solid lines and circle dotted lines represent absorption peaks for the S wave and the P wave, respectively. The other parameters are identical with those in Fig. 1.

Mentions: The above discussions only focus on the case of wave with the normal incidence. In fact, the resonant absorption depends on the incident angle of the wave. This is because the BICs are related to the incident angle of the wave as shown in Fig. 1. The angle properties of absorption peaks depend on the choice of BIC modes, which can be seen clearly in Fig. 5. The solid and dotted lines represent absorption modes for the S wave and the P wave, respectively. Figure 5 shows the positions of absorption peaks as a function of the wavelength λ and the incident angle θ. It is seen clearly that the corresponding between the curves in Fig. 5 with those in Fig. 1(c) and (e) is very well.


Ultrasensitive optical absorption in graphene based on bound states in the continuum.

Zhang M, Zhang X - Sci Rep (2015)

The absorption peaks as a function of the wavelength λ and the incident angle θ.Here a = 5.5185 μm. The solid lines and circle dotted lines represent absorption peaks for the S wave and the P wave, respectively. The other parameters are identical with those in Fig. 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4317701&req=5

f5: The absorption peaks as a function of the wavelength λ and the incident angle θ.Here a = 5.5185 μm. The solid lines and circle dotted lines represent absorption peaks for the S wave and the P wave, respectively. The other parameters are identical with those in Fig. 1.
Mentions: The above discussions only focus on the case of wave with the normal incidence. In fact, the resonant absorption depends on the incident angle of the wave. This is because the BICs are related to the incident angle of the wave as shown in Fig. 1. The angle properties of absorption peaks depend on the choice of BIC modes, which can be seen clearly in Fig. 5. The solid and dotted lines represent absorption modes for the S wave and the P wave, respectively. Figure 5 shows the positions of absorption peaks as a function of the wavelength λ and the incident angle θ. It is seen clearly that the corresponding between the curves in Fig. 5 with those in Fig. 1(c) and (e) is very well.

Bottom Line: By taking suitable BICs, the selective absorption for S and P waves has not only been realized, but also all-angle absorption for the S and P waves at the same time has been demonstrated.We have also found that ultrasensitive strong absorptions can appear at any wavelength from mid-infrared to far-infrared band.These phenomena are very beneficial to biosensing, perfect filters and waveguides.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Beijing Normal University, Beijing 100875, China.

ABSTRACT
We have designed a sphere-graphene-slab structure so that the electromagnetic wave can be well confined in the graphene due to the formation of a bound state in a continuum (BIC) of radiation modes. Based on such a bound state, we have realized strong optical absorption in the monolayer graphene. Such a strong optical absorption exhibits many advantages. It is ultrasensitive to the wavelength because the Q factor of the absorption peak can be more than 2000. By taking suitable BICs, the selective absorption for S and P waves has not only been realized, but also all-angle absorption for the S and P waves at the same time has been demonstrated. We have also found that ultrasensitive strong absorptions can appear at any wavelength from mid-infrared to far-infrared band. These phenomena are very beneficial to biosensing, perfect filters and waveguides.

No MeSH data available.