Comb-Shaped Graphene Nanoribbon Bandpass Filter

2020 ◽  
Vol 20 (12) ◽  
pp. 7577-7582
Author(s):  
Guangsheng Deng ◽  
Tianxiang Zhao ◽  
Zhiping Yin ◽  
Ying Li ◽  
Jun Yang
Keyword(s):  
Finite Difference Time Domain ◽  
Bandpass Filter ◽  
Chemical Potential ◽  
Graphene Nanoribbon ◽  
Frequency Region ◽  
Monolayer Graphene ◽  
Transmission Spectra ◽  
All Optical ◽  
Graphene Devices ◽  
Difference Time

In this study, a novel comb-shaped graphene nanoribbon wideband bandpass filter for use at midinfrared frequencies is proposed. In addition, numerical investigation was carried outwith finite difference time-domain (FDTD) numerical simulations. The filter includes one graphene nanoribbon (GNR) waveguide laterally coupled to six perpendicular GNRs on each side. With a simple geometric shape, the transmission bandwidth and efficiency of waves within the structure can be tuned by altering the width or length of the GNR teeth. Moreover, the transmission spectra can be easily tuned within a broad frequency region by tuning the chemical potential of the graphene teeth, thanks to the electronic tunability of monolayer graphene. This work offers a promising method for developing ultra-compact tunable graphene devices and for designing integrated all-optical architectures.

Tunable plasmonic filter based on graphene-layered waveguide

2018 ◽  
Vol 32 (08) ◽  
pp. 1850110 ◽  
Author(s):  
Yuncai Feng ◽  
Youwen Liu ◽  
Yaoyao Shi ◽  
Jinghua Teng
Keyword(s):  
Finite Difference Time Domain ◽  
Chemical Potential ◽  
Fdtd Method ◽  
Optical Filter ◽  
Monolayer Graphene ◽  
Physical Parameters ◽  
Plasmonic Filter ◽  
Tunable Optical Filter ◽  
Difference Time ◽  
Different Thickness

We propose a tunable band-stop plasmonic filter based on monolayer graphene with different thickness of structure, and the corresponding transmission characteristic is numerically investigated by using finite-difference time-domain (FDTD) method. The results show that the proposed filter can achieve a broad stopband that can be tuned by various physical parameters such as the chemical potential of graphene, the thickness of packing layers and so on. Our studies may be important for designing tunable optical filter, the fabrication of nano-integrated plasmonic circuits and the refractive index sensitive sensors.

Compact and ultrafast all optical 1-bit comparator based on wave interference and threshold switching methods

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Asghar Askarian
Keyword(s):  
Finite Difference Time Domain ◽  
Contrast Ratio ◽  
Logical Structure ◽  
Ring Resonators ◽  
Plane Wave Expansion ◽  
Threshold Switching ◽  
Wave Interference ◽  
All Optical ◽  
Fdtd Methods ◽  
Difference Time

Abstract In this study, we are going to design all optical 1-bit comparator by combining wave interference and threshold switching methods. The final structure composed of two nonlinear ring resonators and seven waveguides. The functionality of the suggested logical structure is analyzed and simulated by using plane wave expansion (PWE) and finite difference time domain (FDTD) methods. According to results, the proposed all optical 1-bit comparator has faster response and smaller footprint than all previous works. The maximum ON-OFF contrast ratio, delay time and area of the suggested optical comparator are about 16.67 dB, 1.8 ps, and 513 µm2, respectively.

scholarly journals A novel proposal based on 2D linear resonant cavity photonic crystals for all-optical NOT, XOR and XNOR logic gates

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Kouddad Elhachemi ◽  
Naoum Rafah
Keyword(s):  
Finite Difference Time Domain ◽  
Resonant Cavity ◽  
Logic Gates ◽  
Low Power Consumption ◽  
Plane Wave Expansion ◽  
Novel Structure ◽  
All Optical ◽  
Easy Integration ◽  
Two Dimensional Photonic Crystal ◽  
Difference Time

AbstractIn this paper, we are going to propose a novel structure of all-optical NOT, XOR and XNOR logic gates are presented using a two-dimensional photonic crystal (2D-PhC). This structure is optimized by varying the radius of the cavity, to obtain a quality factor Q = 1192, and also has several ports of entry and one port of output. The size of each structure is equal to 85.8 μm2. The contrast ratios for the structures proposed all-optical NOT, XOR and XNOR logic gates between levels “0” and “1” are, respectively, 25.08, 25.03, and 14.47 dB. The response time for the three logical gates is 8.33 ps, and the bit rate is calculated at about 0.12 Tbit/s, all simulations are based on both numerical methods such as finite difference time domain (FDTD) and plane wave expansion (PWE). Designed logic gates are characterized by low power consumption, compactness and easy integration.

scholarly journals Size Determination of Polystyrene Sub-Microspheres Using Transmission Spectroscopy

2020 ◽  
Vol 10 (15) ◽  
pp. 5232
Author(s):  
Tien Van Nguyen ◽  
Linh The Pham ◽  
Khuyen Xuan Bui ◽  
Lien Ha Thi Nghiem ◽  
Nghia Trong Nguyen ◽  
...  
Keyword(s):  
Time Domain ◽  
Finite Difference Time Domain ◽  
Fdtd Simulation ◽  
Transmission Spectra ◽  
Experimental Transmission ◽  
Straightforward Method ◽  
Quartz Substrates ◽  
Difference Time ◽  
Good Agreement

Nano/micro polystyrene (PS) beads have found many applications in different fields spanning from drug delivery, bio-diagnostics, and hybrid plasmonics to advanced photonics. The sizes of the PS beads are an important parameter, especially in plasmonic and photonic experiments. In this work, we demonstrate a quick and straightforward method to estimate the diameters of sub-microspheres (0.2 μm to 0.8 μm) using the transmission spectra of a close-packed monolayer of polystyrene beads on glass or quartz substrates. Experimental transmission spectra of the PS monolayers were verified against finite-difference time-domain (FDTD) simulation and showed good agreement. The effects of the substrates on the transmission spectra and, hence, the accuracy of the method were also studied by simulation, which showed that common transparent substrates only cause minor deviation of the PS bead sizes calculated by the proposed method.

Graphene Based Polarization-Dependent Terahertz Photodetector

2021 ◽  
Vol 894 ◽  
pp. 13-20
Author(s):  
Yu Zhe Li
Keyword(s):  
Finite Difference Time Domain ◽  
Room Temperature ◽  
Chemical Potential ◽  
Incident Light ◽  
Localized Surface Plasmon ◽  
High Tech ◽  
Polarization Angle ◽  
Terahertz Frequency ◽  
Terahertz Technology ◽  
Difference Time

Terahertz technology can be used in sensing and communication applications. We designed a polarization-sensitive photodetector specially for Terahertz frequency based on cross-shaped graphene sheet. The shaped graphene excites localized surface plasmon which can enhance the absorption of incident light. From the Finite Difference Time Domain Solutions (FDTD), we figured out that transmission of incident light relates to the size of photodetector, polarization angle and physical properties of graphene such as chemical potential and layers. The transmission can be tuned as low as 8.3 ×10-5 when we set the size at 14×6µm and 14×5µm for two different graphene pieces and polarization angle as 0°, at room temperature. This device we designed can absorb Terahertz at a wavelength around 126 µm, which can be used in THz application applied in future high-tech communication or safety inspection.

Design of All-optical Half-subtractor Circuit Device using 2-D Principle of Photonic Crystal Waveguides

2019 ◽  
Vol 40 (3) ◽  
pp. 195-203 ◽  
Author(s):  
Sandip Swarnakar ◽  
Santosh Kumar ◽  
Sandeep Sharma
Keyword(s):  
Photonic Crystal ◽  
Integrated Circuits ◽  
Finite Difference Time Domain ◽  
Optical Amplifiers ◽  
Photonic Integrated Circuits ◽  
Square Lattice ◽  
Photonic Crystal Waveguides ◽  
Nonlinear Materials ◽  
All Optical ◽  
Difference Time

Abstract A design of all-optical half-subtractor (AOHS) is presented based on two-dimensional (2-D) photonic crystal (PhC) waveguides without using optical amplifiers and nonlinear materials. It is an essential component of various photonic integrated circuits. The design of AOHS circuit is based on beam interference principle, using square lattice of Y-shaped and T-shaped waveguides with silicon dielectric rods in air substrate. It is validated through finite-difference time-domain and using MATLAB simulations.

Design of One-Bit Magnitude Comparator using Photonic Crystals

2019 ◽  
Vol 40 (4) ◽  
pp. 363-367 ◽  
Author(s):  
Sapna Rathi ◽  
Sandip Swarnakar ◽  
Santosh Kumar
Keyword(s):  
Photonic Crystals ◽  
Finite Difference Time Domain ◽  
Lattice Structure ◽  
Sequential Circuits ◽  
Nonlinear Material ◽  
Time Domain Simulation ◽  
Matlab Simulation ◽  
All Optical ◽  
Combinational And Sequential Circuits ◽  
Difference Time

Abstract At present, photonic crystals (PhCs) are used to design various combinational and sequential circuits. In this paper, an all-optical one-bit magnitude comparator is proposed using PhC waveguide without using nonlinear material. It is based on beam interference principle, using T-shaped lattice with silicon dielectric rods in air background. It is demonstrated through finite-difference time-domain simulation and verified numerically using MATLAB simulation. The size of PhC lattice structure can be as small as 19.167a×19.167a, where ‘a’ is the lattice constant of the PhC.

scholarly journals Pulse nonlinear optical switching in plasmonic structures

2020 ◽  
Vol 238 ◽  
pp. 11014
Author(s):  
José R. Salgueiro ◽  
Albert Ferrando
Keyword(s):  
Time Domain ◽  
Finite Difference Time Domain ◽  
Optical Switching ◽  
Nonlinear Optical ◽  
Optical Signal ◽  
Switching Operation ◽  
Plasmonic Structures ◽  
All Optical ◽  
Difference Time ◽  
Interesting System

We study switching operation in a plasmonic coupler using fs-pulses. Simulations using the finite difference time-domain method (FDTD) are carried out showing how the output changes as the pulse energy increases raising from zero to a maximum. Both cases of neglecting and realistic losses are considered in order to compare. The work is intended to explore the use of pulses for all-optical signal processing in a potentially interesting system for integrated photonics at the nanometric scale.

scholarly journals Investigating the Fabrication Imperfections of Plasmonic Nanohole Arrays and Its Effect on the Optical Transmission Spectra

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Amr M. Mahros ◽  
Marwa M. Tharwat
Keyword(s):  
Time Domain ◽  
Finite Difference Time Domain ◽  
Optical Transmission ◽  
Fdtd Method ◽  
Extraordinary Optical Transmission ◽  
Gold Films ◽  
Transmission Spectra ◽  
Nanohole Arrays ◽  
Optical Transmission Spectra ◽  
Difference Time

We investigate the extraordinary optical transmission spectra of thin gold films perforated with imperfect nanohole arrays using the finite difference time domain (FDTD) method. Exponential shapes for the nanohole sidewalls are used. To the best of our knowledge, such investigation of transmission spectra of imperfect nanohole arrays has not previously been demonstrated. It was found that the asymmetry between the two openings of the circular nanoholes or bending to their sidewalls strongly modifies both the intensity and resonance positions of the transmission spectra. Furthermore, the results of this study assist in explaining the technicality of extraordinary optical transmission phenomenon and why some experimental results on transmission differ from those expected.

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