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- 实验方案
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Technical Specifications of the Submarine Fiber Optic Channel Bandwidth/Capacity in Optical Fiber Transmission Systems
摘要： This work outlines technical specifications of the undersea fiber optic communication channel bandwidth, capacity with taken into account the maximum and minimum extended fiber cost in the presence of amplifiers stations. The number of amplifiers in the amplification stage are addressed based on the amplifier distance to strength the light signal in water depth after 5 km distance. The fiber channel capacity is estimated at different water depth and at the surface of the water. Minimum input signal power and required detectable received power are adjusted to ensure the high data rates in submarine cable systems under the best and worst conditions of the seawater pressure. The study emphasizes the high data rates
关键词： wide bandwidth,technical specifications,water pressure,water depth
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Spiral Bandwidth of Four-Wave Mixing in Rubidium Vapour
摘要： Atomic vapours are an experimentally simple and ef?cient system in which to study nonlinear wave mixing. We study a four-wave mixing (FWM) process in rubidium vapour which ef?ciently converts 780 and 776 nm light to 420 nm and 5.2 μm ?elds [1]. In particular, we quantitatively investigate the transfer of orbital angular momentum (OAM) between the FWM ?elds. OAM, and structured light more generally, is an important research tool for optical manipulation, imaging and communication. Phase-matched nonlinear processes are both longitudinally and transversely phase coherent, and therefore OAM, which is associated with spiral phase fronts, must be conserved between the pump and generated ?elds [2]. This makes wave mixing an ideal tool for frequency conversion and generation of a variety of OAM states for use in both classical and quantum communication [3]. In our FWM process, conservation of OAM determines the total OAM carried by the 420 nm and 5.2 μm ?elds - but not how it is distributed between them. Fig. 1 (a) shows the intensity pro?le and interferogram (formed by interfering the beam with its mirror image) of the 420 nm ?eld when the pump beams each carry (cid:2)ˉh of OAM ((cid:2) = (cid:2)780 = (cid:2)776). We perform quantitative analysis of each interferogram to obtain the full Laguerre-Gauss mode decomposition of the 420 nm ?eld (Fig. 1 (b)). For small values of pump OAM, the 420 nm light is generated predominantly in one mode [4], but as the pump OAM increases the OAM spectrum broadens [5]. In order for OAM to be conserved, this indicates that the 420 nm and 5.2 μm light is generated in an OAM-entangled state. From the 420 nm mode decomposition we infer the spiral bandwidth (a measure of the number of entangled modes), Δ(cid:2)B, as well as the entanglement entropy, S, of this state. Both the experimental and theoretical results show that the generated state is strongly pump mode-dependent, with the spiral bandwidth increasing with increasing pump OAM. These results indicate that this system is likely to be an ef?cient source of OAM-entangled photon pairs with widely-disparate wavelengths.
关键词： entanglement entropy,orbital angular momentum,four-wave mixing,rubidium vapour,spiral bandwidth
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - A novel polarization-insensitive optical filter on silicon
摘要： A silicon-based polarization-insensitive optical filter is designed and demonstrated by using dual multimode-waveguide-gratings. For the ~300μm-long device, the 3dB-bandwidth is ~11nm and the excess loss is ~1.5dB for both polarizations.
关键词： bandwidth,polarization-insensitive,optical filter
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Energy Efficiency with Minimized-Regenerators Placement in IP-Over-Flexible Bandwidth Optical Networks
摘要： We propose an optimized energy-efficient algorithm (OEEA) with minimized-regenerators placement to reduce energy consumption in IP-over-flexible bandwidth optical networks. Simulation results show that our proposed algorithm improves energy efficiency compared to traditional algorithm.
关键词： regenerator placement,Flexible bandwidth optical networks,energy efficiency
更新于2025-09-16 10:30:52
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Solution-processed QD-LEDs in visible range: Modulation bandwidth enhancement
摘要： Light-emitting diodes based on quantum dots (QD-LEDs) have attracted much attention not only due to their usage in lighting and display applications but also as the light sources in visible light communication (VLC). One of the most important parameters of a QD-LED as a light source is the improvement of modulation bandwidth in order to increase the data transfer rate. Here, three sets of QD-LEDs are presented for which some parameters such as frequency response are investigated, once for the devices with similar structure but different homogeneities and then for those with minor changes in the structure. It was found that by changing the homogeneity of QDs in the same structure based on CdSe/ZnS and using the ZnO shell instead of ZnS, the modulation bandwidth varied between 2 and 8 MHz. Furthermore, for the structure based on CdSe/ZnS, the modulation bandwidth of 8 MHz is achieved which is fairly a wide bandwidth for a QD-LED. The idea of manipulation in the structure of nanomaterials can be an important step toward increasing the modulation bandwidth. According to calculated results, the carrier density in different layers is calculated and then the recombination current-voltage characteristics are compared with the experimental results, indicating high conformity.
关键词： Light emitting diode,Frequency response,CdSe/ZnS,Quantum dots,Modulation bandwidth
更新于2025-09-16 10:30:52
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Enhanced terahertz emission bandwidth from photoconductive antenna by manipulating carrier dynamics of semiconducting substrate with embedded plasmonic metasurface
摘要： In this article, we demonstrate a technique to enhance the Terahertz (THz) emission bandwidth from photo-conductive antenna (PCA) based on semiconducting substrates by manipulating the surface carrier dynamics of the semiconductor. Bandwidths in PCAs are limited by the decay of the photogenerated charge carriers, which in case of SI-GaAs is in the orders of 50 picoseconds. We show, with an embedded design of plasmonic meta-surface in the photoconductive gap of a PCA, it is possible to enhance the emission bandwidths by more than 50 percent. This is due to the fact that these nano-structures act as local recombination sites for the photogenerated carriers, effectively reducing the carriers’ lifetime. Additionally, the defect sites reduce the terminal current, thereby reducing the Joule heating in the device. Furthermore, the meta-surface also facilitates higher in-coupling of the exciting infrared light on to the PCA, thereby increasing the optical-to-THz conversion efficiency of the device.
关键词： carrier dynamics,plasmonic metasurface,bandwidth enhancement,photoconductive antenna,Terahertz
更新于2025-09-16 10:30:52
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[IEEE 2019 International Workshop on Fiber Optics in Access Networks (FOAN) - Sarajevo, Bosnia and Herzegovina (2019.9.2-2019.9.4)] 2019 International Workshop on Fiber Optics in Access Networks (FOAN) - Load Adaptive Dynamic Wavelength and Bandwidth Assignment for TWDM PON
摘要： Time and Wavelength Division Multiplexing PON (TWDM-PON) is next generation PON technology that increases the PON capacity due to having multiple wavelengths for both upstream and downstream links with tunable transceivers in the optical network units (ONUs). It is also proposed for connecting radio units to the cloud, termed as mobile front-haul, in 5G. The most important feature of TWDM PON is a dynamic wavelength assignment scheme that can efficiently handle ONU migration from one wavelength to another to balance the traffic load. In this study, the working of DWA mechanism for ITU compliant TWDM PON is presented and an adaptive DWBA scheme is presented that can dynamically handle ONU migration in case of asymmetric traffic load conditions. The performance of the proposed scheme is evaluated through a TWDM PON test bed implemented in OMNET++ environment. For the traffic load analysis a simple regression model is used. Overall, the ADWBA scheme reduces the average upstream delays of T2 and T3 up to 28% and of T4 up to 50% with valuable reduction in bandwidth wastage.
关键词： dynamic wavelength,TWDM,bandwidth efficient,passive optical network,dynamic bandwidth assignment,XGPON,DBA
更新于2025-09-12 10:27:22
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Developer Design of Hybrid Plasmonic Nano Patch Antenna with Metal Insulator Metal Multilayer Construction
摘要： Hybrid plasmonic nanopatch antenna with metal-insulator-metal (HMIM) multilayer has been investigated for operation at the frequency of 125–250 THz using the finite element method (FEM) implemented in Ansoft High Frequency Structure Simulator (HFSS). The proposed antenna exhibits a wide bandwidth of 49.5 THz (151.5 THz–201 THz) for the slots thicknesses Wg = 50 nm and Ws = 100 nm and dual bandwidth for Ws = 20 nm. The obtained results show the input impedance of 50.3 Ω input resistance (real part) and 2.3 Ω reactance (imaginary part) occurring at (near) the operation frequency. The maximum gain of 23.98 dB has been observed for resonant frequencies of 176 THz, and the maximum directivity remains above 6.73 dB and 7.46 dB at resonant frequencies of 170 THz and 190 THz, respectively. Our proposed antenna performance is compared to previously reported designs. The copolar and cross-polar radiation patterns are simulated at different resonant frequencies of 160 THz and 197 THz for planes Φ = 90° and Φ = 0° . The arrays of a proposed antenna are designed in one and two dimensions in order to appropriate high-gain applications.
关键词： Ansoft High Frequency Structure Simulator,wide bandwidth,hybrid plasmonic nanopatch antenna,high-gain applications,metal-insulator-metal,finite element method
更新于2025-09-12 10:27:22
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[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Evolution from Air-Cladded to Effective-Medium-Cladded Dielectric Waveguides
摘要： Integrated guiding structures with low loss, low dispersion and broad bandwidth are demanded in high-performance terahertz systems. In this work, an effective-medium-cladded waveguide fabricated on a single high-resistivity silicon wafer is proposed for terahertz operation. The effective medium is realized by regularly perforating a silicon slab with a period in the subwavelength region. The simulated average attenuation coefficient is around 0.05 dB/cm over the operation frequency range from 220 GHz to 330 GHz for the (cid:2)(cid:3)(cid:3) (cid:4) mode.
关键词： low loss,terahertz waveguides,low dispersion,effective-medium-cladded waveguide,broad bandwidth
更新于2025-09-12 10:27:22
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Comparative analysis of microstrip-line-fed gap-coupled and direct-coupled microstrip patch antennas for wideband applications
摘要： An attempt is made to improve the impedance bandwidth (S11) of a microstrip antenna by means of the gap-coupling method, yielding a bandwidth of 97.88% for the gap-coupled rectangular microstrip antenna (GC-RMSA) compared with 7.67% for the direct-coupled rectangular microstrip antenna with all dimensions the same. The maximum gain of the proposed (GC-RMSA) design is 6.725 dB with antenna efficiency of 99.86%. The proposed antenna design is analyzed using the IE3D simulator. The microstrip line feed technique is used to energize the antenna, and its performance as a function of the gap between the elements (g) and the width of the feed strip (W) is investigated. The results show that the impedance bandwidth of the gap-coupled antenna depends on the coupling gap between the elements; indeed, as the gap (g) is increased up to a certain level, the bandwidth of the proposed antenna increases, resulting in a wideband characteristic. However, after a certain value of the gap (g), the bandwidth decreases due to spurious radiation, and the antenna characteristic changes from wide to dual band with a corresponding decrease in the bandwidth. The proposed antenna design covers the frequency range from 2.093 to 6.105 GHz, including the C-band, S-band uplink and downlink frequencies, Wi-Fi, Bluetooth, WLAN, and IEEE (a/b/g) standard applications.
关键词： Gap coupled,Bandwidth,Microstrip line feed,IE3D,WLAN,Direct coupled
更新于2025-09-12 10:27:22