Confining near-infrared (NIR) and mid-infrared (MIR) radiation (1-10 μm) at the nanoscale is one of the main challenges in photonics. Thanks to the transparency of silicon in the NIR-MIR range, optoelectronic systems like electro-optical modulators have been broadly designed in this range. However, the trade-off between energy-per-bit consumption and speed still constitutes a significant bottleneck, preventing such a technology to express its full potentialities. Moreover, the harmless nature of NIR radiation makes it ideal for bio-photonic applications. In this work, we theoretically showcase a new kind of electro-optical modulators in the NIR-MIR range that optimize the trade-off between power consumption, switching speed, and light confinement, leveraging on the interplay between graphene and metamaterials. We investigate several configurations among which the one consisting in a SiO2/graphene hyperbolic metamaterial (HMM) outstands. The peculiar multilayered configuration of the HMM allowed one also to minimize the equivalent electrical capacitance to achieve attoJoule electro/optical modulation at about 500 MHz switching speed. This system manifests the so-called dielectric singularity, in correspondence to which an HMM lens with resolving power of λ/1660 has been designed, allowing to resolve 3 nm-wide objects placed at an interdistance of 3 nm and to overcome the diffraction limit by 3 orders of magnitude. The imaging possibilities opened by such technologies are evident especially in bio-photonic applications, where the investigation of biological entities with tailored/broadband-wavelength radiation and nanometer precision is necessary. Moreover, the modulation performances demonstrated by the graphene-based HMM configure it as a promise for ultrafast and low-power opto-electronics applications.

Near- And Mid-Infrared Graphene-Based Photonic Architectures for Ultrafast and Low-Power Electro-Optical Switching and Ultra-High Resolution Imaging

Caligiuri V.
;
Patra A.;Caputo R.
;
De Luca A.
2020-01-01

Abstract

Confining near-infrared (NIR) and mid-infrared (MIR) radiation (1-10 μm) at the nanoscale is one of the main challenges in photonics. Thanks to the transparency of silicon in the NIR-MIR range, optoelectronic systems like electro-optical modulators have been broadly designed in this range. However, the trade-off between energy-per-bit consumption and speed still constitutes a significant bottleneck, preventing such a technology to express its full potentialities. Moreover, the harmless nature of NIR radiation makes it ideal for bio-photonic applications. In this work, we theoretically showcase a new kind of electro-optical modulators in the NIR-MIR range that optimize the trade-off between power consumption, switching speed, and light confinement, leveraging on the interplay between graphene and metamaterials. We investigate several configurations among which the one consisting in a SiO2/graphene hyperbolic metamaterial (HMM) outstands. The peculiar multilayered configuration of the HMM allowed one also to minimize the equivalent electrical capacitance to achieve attoJoule electro/optical modulation at about 500 MHz switching speed. This system manifests the so-called dielectric singularity, in correspondence to which an HMM lens with resolving power of λ/1660 has been designed, allowing to resolve 3 nm-wide objects placed at an interdistance of 3 nm and to overcome the diffraction limit by 3 orders of magnitude. The imaging possibilities opened by such technologies are evident especially in bio-photonic applications, where the investigation of biological entities with tailored/broadband-wavelength radiation and nanometer precision is necessary. Moreover, the modulation performances demonstrated by the graphene-based HMM configure it as a promise for ultrafast and low-power opto-electronics applications.
2020
all-optical switching
graphene
HMM
hyperbolic metamaterials
light confinement
metal/insulator architectures
ultrafast
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11770/322257
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