High‐modulation depth modulator based on double‐layer graphene with a low bias voltage

2019 ◽  
Vol 14 (5) ◽  
pp. 515-519 ◽  
Author(s):  
Zhou Dapeng ◽  
Xiao Binggang ◽  
Xiao Lihua ◽  
Guo Fenglei ◽  
Wang Xiumin
Keyword(s):  
Double Layer ◽  
Bias Voltage ◽  
Modulation Depth ◽  
Layer Graphene ◽  
High Modulation

scholarly journals Double-layer graphene on photonic crystal waveguide electro-absorption modulator with 12 GHz bandwidth

Nanophotonics ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 2377-2385 ◽  
Author(s):  
Zhao Cheng ◽  
Xiaolong Zhu ◽  
Michael Galili ◽  
Lars Hagedorn Frandsen ◽  
Hao Hu ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Double Layer ◽  
Slow Light ◽  
Modulation Depth ◽  
Photonic Crystal Waveguide ◽  
Optical Modulators ◽  
Layer Graphene ◽  
Silicon Photonic ◽  
On Chip ◽  
Silicon Based

AbstractGraphene has been widely used in silicon-based optical modulators for its ultra-broadband light absorption and ultrafast optoelectronic response. By incorporating graphene and slow-light silicon photonic crystal waveguide (PhCW), here we propose and experimentally demonstrate a unique double-layer graphene electro-absorption modulator in telecommunication applications. The modulator exhibits a modulation depth of 0.5 dB/μm with a bandwidth of 13.6 GHz, while graphene coverage length is only 1.2 μm in simulations. We also fabricated the graphene modulator on silicon platform, and the device achieved a modulation bandwidth at 12 GHz. The proposed graphene-PhCW modulator may have potentials in the applications of on-chip interconnections.

scholarly journals Polarization-Independent Optoelectronic Modulator Based on Graphene Ridge Structure

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2559
Author(s):  
Shiliang Guo ◽  
Xin Li ◽  
Zechen Guo ◽  
Xingtao Zhao ◽  
Shuhan Meng ◽  
...  
Keyword(s):  
Refractive Index ◽  
Double Layer ◽  
Modulation Depth ◽  
Transverse Magnetic ◽  
Absorption Capacity ◽  
Simulation Software ◽  
Comsol Multiphysics ◽  
Ridge Structure ◽  
Layer Graphene ◽  
Polarization Independent

In this paper, we propose a polarization-independent optoelectronic modulator based on the electrical absorption effect of graphene. Firstly, we use the simulation software COMSOL Multiphysics to design the structure, and find via changing the applied voltage on both ends of the graphene that the equivalent refractive index of graphene can be changed, thus changing the light absorption capacity of the modulator. The waveguides in the transverse magnetic (TM) and transverse electric (TE) modes have almost the same extinction coefficient by making a double-layer graphene ridge structure in the center of the silicon-based waveguide, which can achieve approaching modulation depth in the TM and TE modes. At 1550 nm wavelength, the two-dimensional cross-section of the structure is analyzed by the FEM method using COMSOL Multiphysics to obtain the effective refractive index of the structure. The simulation results show that when the distance between the double-layer graphene isolation layer is d = 20 nm, the TE and TM modes can achieve extinction ratios up to 110 dB over the wide communication band by selecting appropriate “ON” and “OFF” switching points. The bandwidth is 173.78 GHz and the insertion loss is only 0.0338 dB.

Double-layer graphene optical modulators based on Fano resonance in all-dielectric metasurfaces

2019 ◽  
Vol 125 (7) ◽  
pp. 073104 ◽  
Author(s):  
Shahram Bahadori-Haghighi ◽  
Rahim Ghayour ◽  
Mohammad Hossein Sheikhi
Keyword(s):  
Double Layer ◽  
Fano Resonance ◽  
Optical Modulators ◽  
Layer Graphene

Out-of-plane shear and out-of plane Young’s modulus of double-layer graphene

2013 ◽  
Vol 564 ◽  
pp. 37-40 ◽  
Author(s):  
Balázs Hajgató ◽  
Songül Güryel ◽  
Yves Dauphin ◽  
Jean-Marie Blairon ◽  
Hans E. Miltner ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Double Layer ◽  
Young's Modulus ◽  
Plane Shear ◽  
Layer Graphene ◽  
Out Of Plane

scholarly journals Moire bands in twisted double-layer graphene

2011 ◽  
Vol 108 (30) ◽  
pp. 12233-12237 ◽  
Author(s):  
R. Bistritzer ◽  
A. H. MacDonald
Keyword(s):  
Double Layer ◽  
Layer Graphene

A Frequency Reconfigurable Antenna based on Few Layer Graphene

2021 ◽  
Vol 36 (5) ◽  
pp. 542-547
Author(s):  
Sheng-lan Wang ◽  
Jing-Song Hong ◽  
Yan Deng ◽  
Zhi-jian Chen
Keyword(s):  
Experimental Evidence ◽  
Bias Voltage ◽  
Direct Current ◽  
Surface Impedance ◽  
Microstrip Line ◽  
Reconfigurable Antenna ◽  
Layer Graphene ◽  
Direct Current Bias ◽  
Few Layer Graphene ◽  
Frequency Reconfigurable Antenna

In this paper, a frequency reconfigurable antenna was presented. This antenna is made up of a square loop and a microstrip line with a gap, in which the few layer graphene (FLG) sheet is located to achieve frequency reconfigurable. FLG is likes a lumped resistor with resistance. And the surface impedance can be adjusted by applying a direct current bias voltage, which obtains two work modes that imitate switch. Additionally, the experimental evidence show the proposed frequency reconfigurable antenna can provide a tunable bandwidth.

scholarly journals Neural Rate and Timing Cues for Detection and Discrimination of Amplitude-Modulated Tones in the Awake Rabbit Inferior Colliculus

2007 ◽  
Vol 97 (1) ◽  
pp. 522-539 ◽  
Author(s):  
Paul C. Nelson ◽  
Laurel H. Carney
Keyword(s):  
Inferior Colliculus ◽  
Dynamic Range ◽  
Modulation Depth ◽  
Average Rate ◽  
Modulation Frequency ◽  
Detection Threshold ◽  
Depth Functions ◽  
Depth Discrimination ◽  
High Modulation ◽  
Envelope Processing

Neural responses to amplitude-modulated (AM) tones in the unanesthetized rabbit inferior colliculus (IC) were studied in an effort to establish explicit relationships between physiological and psychophysical measures of temporal envelope processing. Specifically, responses to variations in modulation depth ( m) at the cell’s best modulation frequency, with and without modulation maskers, were quantified in terms of average rate and synchronization to the envelope over the entire perceptual dynamic range of depths. Statistically significant variations in the metrics were used to define neural AM detection and discrimination thresholds. Synchrony emerged at modulation depths comparable with psychophysical AM detection sensitivities in some neurons, whereas the lowest rate-based neural thresholds could not account for psychoacoustical thresholds. The majority of rate thresholds (85%) were −10 dB or higher (in 20 log m), and 16% of the population exhibited no systematic dependence of average rate on m. Neural thresholds for AM detection did not decrease systematically at higher SPLs (as observed psychophysically): thresholds remained constant or increased with level for most cells tested at multiple sound-pressure levels (SPLs). At depths higher than the rate-based detection threshold, some rate modulation-depth functions were sufficiently steep with respect to the across-trial variability of the rate to predict depth discrimination thresholds as low as 1 dB (comparable with the psychophysics). Synchrony, on the other hand, did not vary systematically with m in many cells at high modulation depths. A simple computational model was extended to reproduce several features of the modulation frequency and depth dependence of both transient and sustained pure-tone responders.

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