Low voltage, high modulation depth graphene THz modulator employing Fabry–Perot resonance in a metal/dielectric/graphene sandwich structure

Jafari, Behnam; Soofi, Hadi; Abbasian, K.

doi:10.1016/j.optcom.2020.125911

Cited by 22 publications

(7 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this equation, ε 0, ε r , and d ox are the vacuum permittivity, dielectric permittivity, and dielectric thickness 46 , 48 , respectively. Figure 2 c demonstrates the graphene chemical potential shift as a gate voltage function.…”

Section: Structure and Methodsmentioning

confidence: 99%

Graphene-based optofluidic tweezers for refractive-index and size-based nanoparticle sorting, manipulation, and detection

Gholizadeh

Jafari

Golmohammadi

2023

Sci Rep

Self Cite

View full text Add to dashboard Cite

This work proposes a novel design composed of graphene nanoribbons-based optofluidic tweezers to manipulate and sort bio-particles with radii below 2.5 nm. The suggested structure has been numerically investigated by the finite difference time domain (FDTD) method employing Maxwell's stress tensor analysis (MST). The finite element method (FEM) has been used to obtain the electrostatic response of the proposed structure. The tweezer main path is a primary channel in the center of the structure, where the microfluidic flow translates the nanoparticle toward this channel. Concerning the microfluid's drag force, the nanoparticles tend to move along the length of the main channel. The graphene nanoribbons are fixed near the main channel at different distances to exert optical forces on the moving nanoparticles in the perpendicular direction. In this regard, sub-channels embedding in the hBN layer on the Si substrate deviate bio-particles from the main path for particular nanoparticle sizes and indices. Intense hotspots with electric field enhancements up to 900 times larger than the incident light are realized inside and around the graphene ribbons. Adjusting the gap distance between the graphene nanoribbon and the main channel allows us to separate the individual particle with a specific size from others, thus guiding that in the desired sub-channel. Furthermore, we demonstrated that in a structure with a large gap between channels, particles experience weak field intensity, leading to a low optical force that is insufficient to detect, trap, and manipulate nanoparticles. By varying the chemical potential of graphene associated with the electric field intensity variations in the graphene ribbons, we realized tunability in sorting nanoparticles while structural parameters remained constant. In fact, by adjusting the graphene Fermi level via the applied gate voltage, nanoparticles with any desired radius will be quickly sorted. Moreover, we exhibited that the proposed structure could sort nanoparticles based on their refractive indices. Therefore, the given optofluidic tweezer can easily detect bio-particles, such as cancer cells and viruses of tiny size.

show abstract

Section: Structure and Methodsmentioning

confidence: 99%

Graphene-based optofluidic tweezers for refractive-index and size-based nanoparticle sorting, manipulation, and detection

Gholizadeh

Jafari

Golmohammadi

2023

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…In this equation, ε 0, ε r , and d ox are the vacuum permittivity, dielectric permittivity, and dielectric thickness [30,31], respectively. Figure 2 (c) demonstrates the graphene chemical potential shift as a gate voltage function.…”

Section: Structure and Methodsmentioning

confidence: 99%

An Inventive Method for Graphene-Based Optofluidic Tweezer to Actively Detection, Sorting, and Manipulation of Nano-bioparticles below 2.5 nm

Gholizadeh

Jafari

Golmohammadi

2022

Preprint

Self Cite

View full text Add to dashboard Cite

This work proposes a novel design composed of graphene nanoribbons-based optofluidic tweezers to manipulate and sort bio-particles with radii below 2.5 nm. The suggested structure has been numerically investigated by the finite difference time domain (FDTD) method employing Maxwell's stress tensor analysis (MST). The finite element method (FEM) has been used to obtain the electrostatic response of the proposed structure. The tweezer main path is a primary channel in the center of the structure, where the microfluidic flow translates the nanoparticle toward this channel. Concerning the microfluid's drag force, the nanoparticles tend to move along the length of the main channel. The graphene nanoribbons are fixed near the main channel at different distances to exert optical forces on the moving nanoparticles in the perpendicular direction. In this regard, sub-channels embedding in the hBN layer on the Si substrate deviate bio-particles from the main path for particular nanoparticle sizes and indices. Intense hotspots with electric field enhancements up to 900 times larger than the incident light are realized inside and around the graphene ribbons. Adjusting the gap distance between graphene nanoribbon and the main channel allows us to separate the individual particle with a specific size from others, thus guiding that in the desired sub-channel. Furthermore, we demonstrated that in a structure with a large gap between channels, particles experience weak field intensity, leading to a low optical force that is insufficient to detect, trap, and manipulate nanoparticles. By varying the chemical potential of graphene associated with the electric field intensity variations in the graphene ribbons, we realized tunability in sorting nanoparticles while structural parameters remained constant. In fact, by adjusting the graphene Fermi level via the applied gate voltage, nanoparticles with any desired radius will be quickly sorted. Moreover, we exhibited that the proposed structure could sort nanoparticles based on their refractive indices. Therefore, the given optofluidic tweezer can detect bio-particles with immense accuracies, such as cancer cells and viruses of tiny size.

show abstract

“…SPPs have attracted much attention in recent years in nanotechnology, due to overcoming the diffraction limit of light and localizing light in the subwavelength range [9][10][11][12][13]. It has significant applications in chemical sensors, biosensors, solar cells, modulators, nano-imaging, and power splitters [14][15][16][17][18][19][20][21][22][23][24]. The SPP sensors have become the most promising structure because of their ability to minimize the size, rapid detection, high responsivity, and high sensitivity along with appropriate selectivity [25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

High sensitivity metal-insulator-metal sensor based on ring-hexagonal resonator with a couple of square cavities connected

Aghaei

Bahador

2022

Phys. Scr.

View full text Add to dashboard Cite

The necessity for cheaper and more efficient sensors has been the main motivation for the use of Metal-Insulator-Metal (MIM) sensors. In this paper, a micro-dimensional refractive index MIM sensor based on surface plasmon polaritons is presented. This sensor has a ring-hexagonal resonator and a pair of squares-ring resonators that are connected to each other. For the proposed structure, magnetic field profile, transmission spectrum, and important sensor parameters such as sensitivity are obtained through the finite-difference time-domain (FDTD) method. By optimizing the dimensions of the resonators, we achieved a sensitivity equivalent to 2115 nm/RIU in the first mode and 2180 nm/RIU in the second mode. The FOM values for the first and second modes were 118.25 RIU-1 and 120.208 RIU-1, respectively. The results show that the ring-hexagonal resonator significantly improves the sensor parameters in both modes. These enhancements can be considered unique due to the simple structure presented and as a result the reduction of construction costs.

show abstract

Low voltage, high modulation depth graphene THz modulator employing Fabry–Perot resonance in a metal/dielectric/graphene sandwich structure

Cited by 22 publications

References 28 publications

Graphene-based optofluidic tweezers for refractive-index and size-based nanoparticle sorting, manipulation, and detection

Graphene-based optofluidic tweezers for refractive-index and size-based nanoparticle sorting, manipulation, and detection

An Inventive Method for Graphene-Based Optofluidic Tweezer to Actively Detection, Sorting, and Manipulation of Nano-bioparticles below 2.5 nm

High sensitivity metal-insulator-metal sensor based on ring-hexagonal resonator with a couple of square cavities connected

Contact Info

Product

Resources

About