Significantly enhanced infrared absorption of graphene photodetector under surface-plasmonic coupling and polariton interference.
Opt Express
; 26(23): 30862-30872, 2018 Nov 12.
Article
em En
| MEDLINE
| ID: mdl-30469978
ABSTRACT
Here, we present a graphene-based long-wavelength infrared photodetector, for enhancing the infrared absorption of which the design consists of magnetic- and electric-plasmon resonators of metasurface to excite the graphene surface-plasmonic polaritons (SPPs). Through tuning the graphene Fermi energy to achieve the distinct resonances in a matching frequency, peak graphene absorbance exceeding 67.2% is confirmed, even when a lossy dielectric is used, and the field angle of view is up to 90°. If the graphene is of a different carrier mobility, then the absorption frequency is lockable, and the device always can keep the system absorbance close to 100 percent. The significantly enhanced graphene absorbance, up to ~29-fold that of a suspended graphene (general 2.3%), is attributed to the surface-plasmonic coupling between the magnetic and the electric resonances, as well as Fabry-Pérot interference of the coherent SPPs. The plasmonic cavity-mode model and equivalent-circuit method developed in this study will also be useful in guiding other optoelectronic device design.
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Bases de dados:
MEDLINE
Idioma:
En
Revista:
Opt Express
Assunto da revista:
OFTALMOLOGIA
Ano de publicação:
2018
Tipo de documento:
Article