Graphene-based Rasorber with Wide Transmission Band and Narrow Transitional Band

2021 ◽  
Author(s):  
Sibo Mao ◽  
Shining Sun ◽  
Xiaochun Liu ◽  
Bian Wu
Keyword(s):  
Transmission Band

scholarly journals Geometrical Scaling of Antiresonant Hollow-Core Fibers for Mid-Infrared Beam Delivery

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 420
Author(s):  
Ang Deng ◽  
Wonkeun Chang
Keyword(s):  
Structural Parameters ◽  
Transmission Band ◽  
Confinement Loss ◽  
Hollow Core ◽  
Core Size ◽  
Core Diameter ◽  
Mid Infrared ◽  
The Core ◽  
Tubular Type ◽  
Beam Delivery

We numerically investigate the effect of scaling two key structural parameters in antiresonant hollow-core fibers—dielectric wall thickness of the cladding elements and core size—in view of low-loss mid-infrared beam delivery. We demonstrate that there exists an additional resonance-like loss peak in the long-wavelength limit of the first transmission band in antiresonant hollow-core fibers. We also find that the confinement loss in tubular-type hollow-core fibers depends strongly on the core size, where the degree of the dependence varies with the cladding tube size. The loss scales with the core diameter to the power of approximately −5.4 for commonly used tubular-type hollow-core fiber designs.

scholarly journals Waveguide divider design based on null of electric field

2021 ◽  
Author(s):  
Leonardo Zappelli
Keyword(s):  
Electric Field ◽  
Theoretical Approach ◽  
Initial Point ◽  
Transmission Band ◽  
Geometric Parameters ◽  
Transmitted Power ◽  
Matching Network ◽  
Large Bandwidth ◽  
Input Matching ◽  
Thin Band

AbstractNowadays, the design of dividers is based on electromagnetic software that optimizes some geometric parameters to obtain the required performance. The choice of the geometry of the discontinuities contained in the divider and of the optimization initial point is quite critical to satisfy the divider requirements. In the last years, it is quite rare to find in the literature a theoretical approach helping the designers in the choice of the divider geometry. Helpful suggestion can derive by the analysis of the electric field in a trial divider that satisfies power division among the output ports in a thin band. In fact, the electric field null can be filled with metallic septa that ensure the same behavior at any frequency. The optimization of the septa position/form with numerical electromagnetic software permits to obtain divider with large bandwidth. A further analysis of the electric field null in the divider permits to add lateral metallic septa that further enlarge the transmission band. Finally, the design of an input matching network increases the transmitted power to the desired value.

scholarly journals Spatial Decomposition of a Broadband Pulse Caused by Strong Frequency Dispersion of Sound in Acoustic Metamaterial Superlattice

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 125
Author(s):  
Yuqi Jin ◽  
Yurii Zubov ◽  
Teng Yang ◽  
Tae-Youl Choi ◽  
Arkadii Krokhin ◽  
...  
Keyword(s):  
Acoustic Pulse ◽  
Frequency Dispersion ◽  
Transmission Band ◽  
Lateral Position ◽  
Operating Frequency ◽  
Frequency Range ◽  
Frequency Spectra ◽  
Acoustic Metamaterial ◽  
Superlattice Structure ◽  
Broadband Pulse

An acoustic metamaterial superlattice is used for the spatial and spectral deconvolution of a broadband acoustic pulse into narrowband signals with different central frequencies. The operating frequency range is located on the second transmission band of the superlattice. The decomposition of the broadband pulse was achieved by the frequency-dependent refraction angle in the superlattice. The refracted angle within the acoustic superlattice was larger at higher operating frequency and verified by numerical calculated and experimental mapped sound fields between the layers. The spatial dispersion and the spectral decomposition of a broadband pulse were studied using lateral position-dependent frequency spectra experimentally with and without the superlattice structure along the direction of the propagating acoustic wave. In the absence of the superlattice, the acoustic propagation was influenced by the usual divergence of the beam, and the frequency spectrum was unaffected. The decomposition of the broadband wave in the superlattice’s presence was measured by two-dimensional spatial mapping of the acoustic spectra along the superlattice’s in-plane direction to characterize the propagation of the beam through the crystal. About 80% of the frequency range of the second transmission band showed exceptional performance on decomposition.

scholarly journals Freestanding bilayer plasmonic waveguide coupling mechanism for ultranarrow electromagnetic-induced transparency band generation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Li Yu ◽  
Yuzhang Liang ◽  
Shuwen Chu ◽  
Huixuan Gao ◽  
Qiao Wang ◽  
...  
Keyword(s):  
Electromagnetic Coupling ◽  
Transmission Band ◽  
Waveguide Structure ◽  
Plasmonic Waveguide ◽  
Plasmonic Nanostructures ◽  
Destructive Interference ◽  
Group Index ◽  
Coupling Mechanism ◽  
Induced Transparency ◽  
Electromagnetic Induced Transparency

AbstractStrong electromagnetic coupling among plasmonic nanostructures paves a new route toward efficient manipulation of photons. Particularly, plasmon-waveguide systems exhibit remarkable optical properties by simply tailoring the interaction among elementary elements. In this paper, we propose and demonstrate a freestanding bilayer plasmonic-waveguide structure exhibiting an extremely narrow transmission peak with efficiency up to 92%, the linewidth of only 0.14 nm and an excellent out of band rejection. The unexpected optical behavior considering metal loss is consistent with that of electromagnetic induced transparency, arising from the destructive interference of super-radiative nanowire dipolar mode and transversal magnetic waveguide mode. Furthermore, for slow light application, the designed plasmonic-waveguide structure has a high group index of approximately 1.2 × 105 at the maximum of the transmission band. In sensing application, its lowest sensing figure of merit is achieved up to 8500 due to the ultra-narrow linewidth of the transmission band. This work provides a valuable photonics design for developing high performance nano-photonic devices.

Multi-band planar diplexers with sub-sets of frequency-contiguous transmission bands

2021 ◽  
pp. 1-11
Author(s):  
Roberto Gómez-García ◽  
Li Yang ◽  
José-María Muñoz-Ferreras ◽  
Dimitra Psychogiou
Keyword(s):  
High Frequency ◽  
Transmission Band ◽  
Satellite Communications ◽  
Proof Of Concept ◽  
Transmission Zeros ◽  
Cascade Connection ◽  
Coupling Techniques ◽  
In Series ◽  
Mobile Satellite ◽  
Multi Band

Abstract A class of multi-band planar diplexer with sub-sets of frequency-contiguous transmission bands is reported. Such a radio frequency (RF) device is suitable for lightweight high-frequency receivers aimed at multi-band/multi-purpose mobile satellite communications systems. It consists of two channelizing filters, each of them being made up of the in-series cascade connection of replicas of a constituent multi-passband/multi-embedded-stopband filtering stage. This building filtering stage defines a multi-passband transfer function for each channel, in which each main transmission band is split into various sub-passbands by the multi-stopband part. In this manner, each split passband gives rise to several sub-passbands that are imbricated with their counterpart ones of the other channel. The theoretical RF operational principles of the proposed multi-band diplexer approach with sub-sets of imbricated passbands are detailed by means of a coupling–routing–diagram formalism. Besides, the generation of additional transmission zeros in each channelizing filter for higher-selectivity realizations by exploiting cross-coupling techniques into it is also detailed. Furthermore, for experimental demonstration purposes, a microstrip proof-of-concept prototype of second-order octo-band diplexer in the frequency range of 1.5–2.5 GHz that consists of two quad-band channelizing filters with pairs of imbricated passbands is developed and characterized.

Simulation of Broadband Transmission Photonic Crystal Waveguide Crossing with Linear Taper

2013 ◽  
Vol 479-480 ◽  
pp. 133-136
Author(s):  
Yih Bin Lin ◽  
Rei Shin Chen ◽  
Ting Chung Yu ◽  
Ju Feng Liu
Keyword(s):  
Photonic Crystal ◽  
Finite Difference ◽  
Cross Talk ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Transmission Band ◽  
Time Domain Method ◽  
Photonic Crystal Waveguide ◽  
Difference Time ◽  
Novel Design

A novel design of photonic crystal waveguide crossing with taper structure is proposed. Simulations are performed by finite-difference time-domain method. The results show the proposed design has both high transmission and low cross talk characteristics. The transmission band and low cross talk band can be tuned to match each other by adjusting the taper structure..

scholarly journals Evaluation of ZigBee Topology Effect on Throughput and End to End Delay Due to Different Transmission Bands for IoT Applications

2020 ◽  
Vol 16 (3) ◽  
pp. 254-259
Author(s):  
Yehia R. Hamdy ◽  
Ahmed I Alghannam
Keyword(s):  
Ieee 802.15.4 ◽  
Transmission Band ◽  
Maximum Throughput ◽  
Iot Applications ◽  
End To End Delay ◽  
Star Tree ◽  
Minimum Delay ◽  
End To End ◽  
Riverbed Modeler ◽  
Ieee 802.15.4 Standard

ZigBee is widely used in wireless network in Internet of Things (IoT) applications to remotely sensing and automation due to its unique characteristics compared to other wireless networks. According to ZigBee classification of IEEE 802.15.4 standard, the network consists of four layers. The ZigBee topology is represented in second layer. Furthermore, the ZigBee topology consists of three topologies, star, tree and mesh. Also there are many transmission bands allowed in physical layer, such as 2.4 GHz, 915 MHz, 868 MHz. The aim of this paper is to evaluate the effect of ZigBee topologies on End to End delay and throughput for different transmission bands. Riverbed Modeler is used to simulate multiple ZigBee proposed scenarios and collect the results. The results of the study recommend which topology should be used at each transmission band to provide lowest End to End delay or obtain maximum throughput, which is case sensitive in some IoT applications that required for example minimum delay time or sending high amount of data.

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