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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.


Absorption for the sphere-graphene-slab structure as a function of wavelength λ at various lattice constants under the normal incident wave.The other parameters are identical with those in Fig. 1.
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f4: Absorption for the sphere-graphene-slab structure as a function of wavelength λ at various lattice constants under the normal incident wave.The other parameters are identical with those in Fig. 1.

Mentions: Another advantage of such a design is that the resonant absorption peak can appear in the broad frequency range by choosing parameters of the structure. This is because the appearance of BICs strongly depends on the structure parameters. Through choosing suitable structure parameters, we can construct BICs and realize resonant absorptions of EM wave at any wavelength from mid-infrared to far-infrared band. For example, the resonant absorption peak appears at λ = 15.0 μm when the lattice constant is taken as a = 5.5185 μm as shown by the solid line in Fig. 4. It appears at λ = 29.9 μm, 44.8 μm and 59.6 μm (see dashed line, dotted line and dash-dotted line), respectively, when the lattice constant becomes 11.037 μm, 16.556 μm and 22.074 μm.


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

Zhang M, Zhang X - Sci Rep (2015)

Absorption for the sphere-graphene-slab structure as a function of wavelength λ at various lattice constants under the normal incident wave.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

f4: Absorption for the sphere-graphene-slab structure as a function of wavelength λ at various lattice constants under the normal incident wave.The other parameters are identical with those in Fig. 1.
Mentions: Another advantage of such a design is that the resonant absorption peak can appear in the broad frequency range by choosing parameters of the structure. This is because the appearance of BICs strongly depends on the structure parameters. Through choosing suitable structure parameters, we can construct BICs and realize resonant absorptions of EM wave at any wavelength from mid-infrared to far-infrared band. For example, the resonant absorption peak appears at λ = 15.0 μm when the lattice constant is taken as a = 5.5185 μm as shown by the solid line in Fig. 4. It appears at λ = 29.9 μm, 44.8 μm and 59.6 μm (see dashed line, dotted line and dash-dotted line), respectively, when the lattice constant becomes 11.037 μm, 16.556 μm and 22.074 μm.

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.