Papers by sahar behroozinia
arXiv: Optics, 2020
In this paper, we exploit the metagrating paradigm to achieve coherent control of absorption and ... more In this paper, we exploit the metagrating paradigm to achieve coherent control of absorption and reflection in a two-port device. Employing graphene ribbon as a tunable element allows us to, for the first time, realize a reconfigurable metagrating that integrates diversified coherent functionalities into a single planar structure. It is illustrated that the suggested design can behave as a coherent perfect absorber at multiple operating incident angles offered by its period-reconfigurability. Besides, our proposed metagrating is also capable of highly-efficient dynamic beam steering based on the coherent interaction of light with light through finely adjusting its chemical potentials, and its compatibility is then investigated to realize linear all-optical logic gates. Moreover, we use the idea of graphene-based metagrating to put forward an extremely asymmetrical device which exhibits high retroreflection upon illumination from one side and a strong absorption under excitation from...
Optics Letters, 2020
Acquiring full control over a large number of diffraction orders can be strongly attractive in th... more Acquiring full control over a large number of diffraction orders can be strongly attractive in the case of realizing multifunctional devices such as multichannel reflectors. Recently, the concept of metagrating has been introduced, which enables obtaining the desired diffraction pattern through a sparse periodic array of engineered scatterers. In this Letter, for the first time, to the best of our knowledge, a tunable all-graphene multichannel meta-reflector is proposed for operating at terahertz (THz) frequencies. In the supercell level, the designed metagrating is composed of three graphene ribbons of different controllable chemical potentials which can be regarded as a five-channel THz meta-reflector. By choosing proper distribution of DC voltages feeding the ribbons, our design can realize different intriguing functionalities such as anomalous reflection, retroreflection, and three-channel power splitting within a single shared aperture and with high efficiency. This Letter pave...
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Papers by sahar behroozinia