Quadruple plasmon-induced transparency and tunable multi-frequency switch in monolayer graphene terahertz metamaterial

2022 ◽  
Author(s):  
Yuhui Li ◽  
Yiping Xu ◽  
Jiabao Jiang ◽  
Liyong Ren ◽  
Shubo Cheng ◽  
...  
Keyword(s):  
Electric Field ◽  
Modulation Depth ◽  
Spectral Response ◽  
Incident Light ◽  
Extinction Ratio ◽  
Fdtd Method ◽  
Monolayer Graphene ◽  
Destructive Interference ◽  
Induced Transparency ◽  
Plasmon Induced Transparency

Abstract A monolayer graphene metamaterial composed of a graphene block and four graphene strips, which has the metal-like properties in terahertz frequency range, is proposed to generate an outstanding quadruple plasmon-induced transparency (PIT). Additional analyses show that the forming physical mechanism of the PIT with four transparency windows can be explained by strong destructive interference between the bright mode and the dark mode, and the distributions of electric field intensity and electric field vectors under the irradiation of the incident light. Coupled mode theory (CMT) and finite-difference time-domain (FDTD) method are employed to study the spectral response characteristics of the proposed structure, and the theoretical and simulated results are in good agreement. It is found that a tunable multi-frequency switch and excellent optical storage can be achieved in the wide PIT window. The maximum modulation depth is up to 99.7%, which corresponds to the maximum extinction ratio of 25.04 dB and the minimum insertion loss of 0.19 dB. In addition, the time delay is as high as 0.919 ps, the corresponding group refractive index is up to 2755. Thus, the proposed structure provides a new method for the design of terahertz multi-frequency switches and slow light devices.

Dynamically tunable plasmon-induced transparency effect based on graphene metasurfaces

2021 ◽  
Author(s):  
Shuxian Chen ◽  
Junyi Li ◽  
Zicong Guo ◽  
Li Chen ◽  
Kunhua Wen ◽  
...  
Keyword(s):  
Modulation Depth ◽  
Incident Light ◽  
Polarization Angle ◽  
Refractive Index Sensitivity ◽  
Coupled Mode ◽  
Terahertz Devices ◽  
Index Sensitivity ◽  
Induced Transparency ◽  
Difference Time ◽  
Plasmon Induced Transparency

Abstract Plasmon-induced transparency (PIT) is theoretically explored with a graphene metamaterial using finite-difference time-domain numerical simulations and coupled-mode-theory theoretical analysis. In this work, the proposed structure is consisted of one rectangular cavity and three strips to generate the PIT phenomenon. The PIT window can be regulated dynamically by adjusting the Fermi level of the graphene. Importantly, the modulation depth of the amplitude can reach 90.4%. The refractive index sensitivity of the PIT window is also investigated, and the simulation result shows that a sensitivity of 1.335 THz/RIU is achieved. Additionally, when the polarization angle of the incident light is changed gradually from 0˚ to 90˚, the performances of the structure are greatly affected. Finally, the proposed structure is particularly enlightening for the design of dynamically tuned terahertz devices.

Tunable anisotropic plasmon-induced transparency in black phosphorus-based metamaterials

2021 ◽  
Author(s):  
Li Huang ◽  
Zhongpeng Jia ◽  
Bin Tang
Keyword(s):  
Slow Light ◽  
Incident Light ◽  
Fdtd Method ◽  
Infrared Region ◽  
Photonic Devices ◽  
Black Phosphorus ◽  
Lorentz Oscillator ◽  
New Type ◽  
Induced Transparency ◽  
Plasmon Induced Transparency

Abstract Black phosphorus (BP), as a new type of two-dimensional material, has drawn considerable interest because of its distinct physics and electronic characteristics. In this work, we theoretically present a BP-based metamaterial, unit cell of which is composed of a rectangular BP nano-patch and two parallel BP strips. The research results indicate that tunable anisotropic plasmon-induced transparency (PIT) effect can be achieved in the presented metamaterials when the polarization of incident light is along armchair and zigzag directions of BP crystal, respectively. Moreover, the spectra responses and group delay accompanied by the PIT effect can be actively controlled by adjusting the carrier density and geometric parameters. The electromagnetic simulation results calculated by finite-difference time-domain (FDTD) method show good agreement with the coupled Lorentz oscillator model. Our proposed nanostructure provides a new path for designing photonic devices such as slow light and photodetector in the mid-infrared region.

Numerical analysis of Bragg grating-based slot-micro-ring coupling resonator system for electromagnetically-induced transparency-like effect

2020 ◽  
Vol 34 (28) ◽  
pp. 2050307
Author(s):  
C. Y. Zhao ◽  
P. Y. Chen ◽  
C. M. Zhang
Keyword(s):  
Light Field ◽  
Slow Light ◽  
Spectral Response ◽  
Incident Light ◽  
Extinction Ratio ◽  
Fdtd Method ◽  
Resonant Peak ◽  
Bragg Grating ◽  
Slot Waveguide ◽  
Sensor Structure

We propose a novel bio-sensor structure composed of double sided-wall Bragg gratings and dual-slot-micro-ring waveguides. The slot waveguide is a better choice to interact the bio-material under investigation with the propagating light with in the slot region. The incident light field propagates clockwise through the slot micro-ring resonator, the reflection light field propagates counterclockwise in the slot Bragg grating. By optimizing the geometric parameters of the device, the spectral response is tailored to obtain a sharp resonant peak simulated by the finite- difference time-domain (FDTD) method. The spectrum can be tuned not only by geometrically changing the couple distance in slot Bragg grating resonator, but also by dynamically altering the depth and number of the Bragg grating. Furthermore, the device is easy to yield an extinction ratio of 11 dB, a FWHM of 1.1 nm and a quality factor of [Formula: see text]. The device with a small footprint can enable integration with some photonic devices on a chip and have great promising for applications including tunable sensors, slow-light devices and optical communication.

Tunable dual plasmon-induced transparency and slow-light analysis based on monolayer patterned graphene metamaterial

2022 ◽  
Author(s):  
Pengju Yao ◽  
Biao Zeng ◽  
Enduo Gao ◽  
Hao Zhang ◽  
Chao Liu ◽  
...  
Keyword(s):  
Absorption Rate ◽  
Slow Light ◽  
Monolayer Graphene ◽  
Destructive Interference ◽  
Group Index ◽  
Coupled Mode ◽  
External Bias ◽  
Internal Mechanism ◽  
Induced Transparency ◽  
Plasmon Induced Transparency

Abstract We propose a novel terahertz metamaterial structure based on patterned monolayer graphene. This structure produces an evident dual plasmon-induced transparency (PIT) phenomenon due to destructive interference between bright and dark modes. Since the Fermi level of graphene can be adjusted by an external bias voltage, the PIT phenomenon can be tuned by adjusting the voltage. Then the coupled-mode theory (CMT) is introduced to explore the internal mechanism of the PIT. After that, we investigate the variation of absorption rate at different graphene carrier mobilities, and it shows that the absorption rate of this structure can reach 50%, which is a guideline for the realization of graphene terahertz absorption devices. In addition, through the study of the slow-light performance for this structure, it is found that its group index is as high as 928, which provides a specific theoretical basis for the study of graphene slow-light devices.

Dual plasmon-induced transparency and slow light effect in monolayer graphene structure with rectangular defects

2018 ◽  
Vol 52 (2) ◽  
pp. 025104 ◽  
Author(s):  
Hui Xu ◽  
Mingzhuo Zhao ◽  
Mingfei Zheng ◽  
Cuixiu Xiong ◽  
Baihui Zhang ◽  
...  
Keyword(s):  
Slow Light ◽  
Monolayer Graphene ◽  
Light Effect ◽  
Induced Transparency ◽  
Plasmon Induced Transparency

scholarly journals Dual-Mode On-to-Off Modulation of Plasmon-Induced Transparency and Coupling Effect in Patterned Graphene-Based Terahertz Metasurface

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Zhimin Liu ◽  
Enduo Gao ◽  
Zhenbin Zhang ◽  
Hongjian Li ◽  
Hui Xu ◽  
...  
Keyword(s):  
Slow Light ◽  
Coupling Effect ◽  
Structural Parameters ◽  
Fdtd Simulation ◽  
Destructive Interference ◽  
Dual Mode ◽  
Coupled Mode ◽  
Induced Transparency ◽  
Difference Time ◽  
Plasmon Induced Transparency

AbstractThe plasmon-induced transparency (PIT), which is destructive interference between the superradiation mode and the subradiation mode, is studied in patterned graphene-based terahertz metasurface composed of graphene ribbons and graphene strips. As the results of finite-difference time-domain (FDTD) simulation and coupled-mode theory (CMT) fitting, the PIT can be dynamically modulated by the dual-mode. The left (right) transmission dip is mainly tailored by the gate voltage applied to graphene ribbons (stripes), respectively, meaning a dual-mode on-to-off modulator is realized. Surprisingly, an absorbance of 50% and slow-light property of 0.7 ps are also achieved, demonstrating the proposed PIT metasurface has important applications in absorption and slow-light. In addition, coupling effects between the graphene ribbons and the graphene strips in PIT metasurface with different structural parameters also are studied in detail. Thus, the proposed structure provides a new basis for the dual-mode on-to-off multi-function modulators.

scholarly journals Tunable Plasmon-Induced Transparency through Bright Mode Resonator in a Metal–Graphene Terahertz Metamaterial

2020 ◽  
Vol 10 (16) ◽  
pp. 5550
Author(s):  
Guanqi Wang ◽  
Xianbin Zhang ◽  
Xuyan Wei
Keyword(s):  
Group Delay ◽  
Monolayer Graphene ◽  
Device Structure ◽  
Coupling Condition ◽  
Conductive Film ◽  
Induced Transparency ◽  
Bright Mode ◽  
Mode Resonator ◽  
The Ideal ◽  
Plasmon Induced Transparency

The combination of graphene and metamaterials is the ideal route to achieve active control of the electromagnetic wave in the terahertz (THz) regime. Here, the tunable plasmon-induced transparency (PIT) metamaterial, integrating metal resonators with tunable graphene, is numerically investigated at THz frequencies. By varying the Fermi energy of graphene, the reconfigurable coupling condition is actively modulated and continuous manipulation of the metamaterial resonance intensity is achieved. In this device structure, monolayer graphene operates as a tunable conductive film which yields actively controlled PIT behavior and the accompanied group delay. This device concept provides theoretical guidance to design compact terahertz modulation devices.

Numerical analysis of effective refractive index bio-sensor based on graphene-embedded slot-based dual-micro-ring resonator

2020 ◽  
Vol 34 (17) ◽  
pp. 2050145
Author(s):  
C. Y. Zhao ◽  
P. Y. Chen ◽  
P. Y. Li ◽  
C. M. Zhang
Keyword(s):  
Electromagnetically Induced Transparency ◽  
Extinction Ratio ◽  
Fdtd Method ◽  
Ring Resonators ◽  
Compact Structure ◽  
Coupled Mode ◽  
Mode Field ◽  
Sensor Structure ◽  
On Chip ◽  
Induced Transparency

We propose a novel bio-sensor structure composed of slot dual-micro-ring resonators and mono-layer graphene. Based on the electromagnetically induced transparency (EIT)-like phenomenon and the light-absorption characteristics of graphene, we present a theoretical analysis of transmission by using the coupled mode theory and Kubo formula. The results demonstrate the EIT-like spectrum with asymmetric line profile. The mode-field distributions of transmission spectrum are obtained from 3D simulations based on finite-difference time-domain (FDTD) method. Our bio-sensor exhibits theoretical sensitivity of 330 nm/RIU, a minimum detection limit of [Formula: see text] RIU, the maximum extinction ratio of 4.4 dB, the quality factor of [Formula: see text] and a compact structure of [Formula: see text]. Finally, the bio-sensor’s performance is simulated for glucose solution. Our proposed design provides a promising candidate for on-chip integration with other silicon photonic element.

scholarly journals Optical tunable multifunctional slow light device based on double monolayer graphene grating-like metamaterial

2021 ◽  
Author(s):  
Hui Xu ◽  
Xiaojing Wang ◽  
Zhiquan Chen ◽  
Xuelei Li ◽  
Longhui He ◽  
...  
Keyword(s):  
Slow Light ◽  
Incident Light ◽  
Monolayer Graphene ◽  
Group Index ◽  
Dark Mode ◽  
Coupled Mode ◽  
Frequency Selection ◽  
Electrostatic Doping ◽  
Tunable Device ◽  
Induced Transparency

Abstract A very simple optical tunable device, which can realize multiple functions of frequency selection, reflection and slow light, is presented at the investigation. The proposed device is constructed by a periodic grating-like structure. There are two dielectrics (graphene and silicon) in a period of the equivalent grating. The incident light will strongly resonate with the graphene of electrostatic doping, forming an evanescent wave propagating along the surface of graphene, and this phenomenon is the surface plasmon. Under constructive interference of the polaritons, a unique plasmonic induced transparency phenomenon will be achieved. The induced transparency produced by this device can be well theoretically fitted by the bright and dark mode of optical equivalent cavity which can be called coupled mode theory (CMT). This theory can well analyze the influence of various modes and various losses between the function of this device. The device can use gate voltages for electrostatic doping in order to change the graphene carrier concentration and tune the optical performance of the device. Moreover, the length of the device in y-direction is will be much larger than the length of single cycle, providing some basis for realizing the fast tunable function and laying a foundation for the integration. Through a simulation and calculation, we can find that the group index and group delay of this device are as high as 515 and 0.257 picoseconds (ps) respectively, so it can provide a good construction idea for the slow light device. The proposed grating-like metamaterial structure can provide certain simulation and theoretical help for the optical tunable reflectors, absorbers, and slow light devices.

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