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- 摘要
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- 实验方案
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[IEEE 2018 16th International Conference on Emerging eLearning Technologies and Applications (ICETA) - Stary Smokovec, Slovakia (2018.11.15-2018.11.16)] 2018 16th International Conference on Emerging eLearning Technologies and Applications (ICETA) - High-Capacity Wavelength Division Multiplexing Optical Transmission Systems
摘要： The new services and constantly growing number of users develop constant pressure for current transmission systems. Although the first optical systems started to be used at the beginning of 1980s, the last forty years have brought unprecedented development of these systems. Today's optical transmission systems play key role for satisfaction bandwidth demands. This paper provides short insight into the technological evolution of optical transmission systems and show why these systems are mostly used in long-haul and metro networks. The first transmission systems had transmission capacity around 45 Mb/s, today's capacity is beyond 2 Pb/s. We looked at the key technologies as well as their future trends.
关键词： optical transmission systems,wavelength division multiplexing,bandwidth demands,WDM,CWDM,DWDM,optical fiber
更新于2025-09-23 15:19:57
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Large-area grain-boundary-free copper films for plasmonics
摘要： Ultrasmooth single-crystalline metallic thin films provide several key advantages for the fabrication of well-defined and high-resolution plasmonic nanostructures, particularly complex integrated nanocircuits. For this purpose, copper is generally regarded as a poor plasmonic material compared to gold and silver because of its notorious oxidation issues when subjected to air exposure. Here, we report on the use of large-area grain-boundary-free copper films grown epitaxially on sapphire substrates in combination with focused ion beam milling to pattern plasmonic nanostructures with superior quality. The copper surfaces prepared using a single-crystalline copper sputtering target exhibit a very low roughness without any grain boundaries for varying film thicknesses and a strong resistance to oxidation, overcoming the bottleneck in conventional copper film fabrication. Surface plasmon resonance measurements show that improved dielectric constants with higher conductivity and long-term stability can be achieved using the single-crystalline copper films. Plasmonic nanohole arrays patterned from these high-quality films are found to display a stronger field enhancement compared to those made from polycrystalline copper films, thus resulting in an enhanced extraordinary optical transmission performance. This study suggests that our fabrication method is ideally suited for applications in copper-based plasmonic and nanophotonic devices as well as integrated nanocircuits on a large scale.
关键词： Single-crystalline films,Polycrystalline films,Surface plasmon resonances,Copper,Extraordinary optical transmission
更新于2025-09-23 15:19:57
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Loss compensated extraordinary transmission in hybridized plasmonic nanocavities
摘要： Extraordinary optical transmission has been utilized in many optical applications, but the plasmonic losses hinder their full potential. To obtain enhanced transmission, one of the loss compensation methods is to introduce gain. However, an enhanced transmission or even eliminated absorption does not guarantee plasmonic loss compensation. Here, we reveal the distinction between the transmission enhancement mechanisms in gain-assisted plasmonic arrays. To uncover the underlying mechanisms of the modi?ed transmissions, we calculate the e?ective electric permittivity by employing a self-consistent gain model. We demonstrate that a large transmission enhancement in a plasmonic system composed of periodic nanocavities and coaxially placed nanoislands, is led by the loss compensation, which manifests itself as narrowing in e?ective permittivity. In contrast, a slight transmission enhancement in a plasmonic array without the nanoislands arises from the background ampli?cation.
关键词： gain,loss,extraordinary optical transmission,plasmon hybridization,compensation
更新于2025-09-23 15:19:57
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Tunable plasmonic properties of graphene ribbon for hypersensitive nanosensing
摘要： Plasmonic sensing based on symmetrical and asymmetrical graphene metamaterials at the infrared region are proposed and investigated numerically by using three dimensional finite-difference time-domain (FDTD) method. The simple unit cell structure is composed of two parallel graphene ribbons and strips. It is shown that transmission resonance dip shifts can be achieved with a variation of the chemical potential of the graphene ribbon.The sensitivity of the proposed metamaterial is also calculated. Our simulations reveal that, by modulating the chemical potential from 0.8 eV to 0.5 eV, a single layer asymmetrical graphene ribbon can achieve a sensitivity of 6500 nm/RIU, compared to 5725 nm/RIU for double layer asymmetrical graphene ribbons. The finding will pave the way towards graphene based tunable devices for sensing in infrared region.
关键词： Surface plasmon resonance,Metamaterial,Graphene,Optical transmission
更新于2025-09-19 17:13:59
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Transition from discrete patches to plasmonic nanohole array by glancing angle deposition on nanosphere monolayers
摘要： By combining nanosphere lithography and glancing angle deposition, a morphological transition from disconnected patchy silver (Ag) coated nanosphere particles to a connected Ag nanohole sheet on close-packed nanosphere monolayers has been demonstrated, which significantly changes the optical property of the Ag nanostructure deposited. For different sized nanosphere monolayers, when the vapor incident angle was set to be 55o, the transmission spectra showed complicated features when the Ag deposition thickness was less than 60 nm. When the thickness was large enough (> 60 nm), a distinguished extraordinary optical transmission (EOT) peak was observed. The EOT peak wavelength position is independent of the Ag thickness deposited and is proportional to the nanosphere diameter. The obtained EOT peaks possess a high quality factor and have high transmission values compared to those reported in the literature for similar structures. Such a high quality EOT response could be used for constructing better sensors or developing other plasmonic applications.
关键词： extraordinary optical transmission,nanosphere lithography,glancing angle deposition,silver nanoparticles,plasmonic nanohole array
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Effect of PECVD a-Si Growth Temperature on the Performance of a-Si/c-Si Solar Cells
摘要： This paper focuses on upstream signaling in TWDM-PON (one of the two systems speci?ed in the new series of ITU-T G.989.x Recommendations for NG-PON2), for what concerns the discovery phase of a new ONU. The key idea is that a new ONU, that needs to be discovered by the OLT, would send a low bit rate signal that is set to a suf?ciently low-power level to not affect signi?cantly the upstream transmission performance of already active ONUs. We properly dimension the key physical layer parameters of this technique and demonstrate it experimentally. We named this proposal as “photon ranging” due to its ultralow-power transmission and we experimentally demonstrate its feasibility. As a “side effect” of this study, we had to deeply revise the power penalty generated by the optical interferometric crosstalk, the main impairment that impacts the proposed setup, obtaining new results that may be of interest also in areas not directly related to the speci?c framework of TWDM-PON.
关键词： Interferometric crosstalk,optical networks,optical transmission
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) - Picometre Resolution Measurement of Plasmonic Dynamics in Metal Nanostructures using Frequency Comb
摘要： The plasmonic phenomenon of extra-ordinary optical transmission (EOT) refers to the interaction of the light and a metallic film perforated with the subwavelength holes. It provides a larger transmission of electromagnetic fields than the expected values by classical optics. Most precedent researches have been based on intensity measurements. Meanwhile, in optical spectroscopy, broadband phase spectra are known to provide richer, linear, and more direct sources of information on target samples compared to traditional intensity spectra. The direct acquisition of phase spectra, however, has proven difficult in plasmonics, owing to the critical requirements for highly stabilised light sources, coherent optical interferometers, and stable optical paths. The frequency comb provides millions of well-defined optical modes over a broad spectrum with a high phase coherence referenced to an atomic clock of a time standard. Herein, this research demonstrates an interferometric approach to measure the plasmonic EOT phase using a frequency comb as a novel light source for plasmonics.
关键词： phase spectroscopy,plasmonic dynamics,extra-ordinary optical transmission,frequency comb
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) - Artificial Neural Network Equalizers for PAM-4 using DML-on-Silicon
摘要： Nonlinear equalizers (NLEs) based on artificial neural networks (ANNs) are studied for short-reach 4-level pulse amplitude modulation (PAM-4) transmissions utilizing directly-modulated membrane lasers fabricated on silicon substrates (DMLs-on-Si). Using 28-GBaud signals over 2-km of single-mode fiber (SMF), we compare two ANN-NLEs with a previously developed reduced-complexity Volterra-NLE (VNLE).
关键词： Optical Transmission,DML-on-Silicon,Nonlinear Equalizers,PAM-4,Artificial Neural Network
更新于2025-09-11 14:15:04
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Proof-of-Concept of Polarization-Multiplexed PAM using a Compact Si-Ph Device
摘要： We experimentally propose and demonstrate how to double the capacity per wavelength in short distance data center links by polarization multiplexing two PAM streams and by using a very compact Silicon Photonic polarization rotator driven by an algorithm implemented in a low speed DSP platform, avoiding more complex coherent and/or Stokes receiver structures. Tackling up to 100 rad/sec, the system gives automatic stabilization against polarization fluctuations. We also report on the experimentally measured evolution of the state of polarization in an installed data center link.
关键词： Short-Reach Optical Transmission,Polarization Multiplexing,Silicon Photonics
更新于2025-09-10 09:29:36
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O12 scintillator
摘要： The characteristics of a Gd3Al2Ga3O12 crystal scintillator doped with cerium and co-doped with magnesium and titanium have been studied, mainly in view of using it for the Phase II upgrade of the LHCb electromagnetic calorimeter. Samples of the scintillator were irradiated with γ (60Co) to 2 kGy and with 24 GeV protons to 900 kGy. The proton fluence value was ～3·1015 cm?2. It was found that γ-irradiation did not produce any change in the optical transmission of the crystals in the spectral range of the scintillation light, whereas a degradation after the proton irradiation was measurable. For the 1 cm thick sample, a loss of transmission of 3.6% was measured at the wavelength of maximum scintillation (520 nm), and the measured induced absorption coefficient at this wavelength was ～3.6 m?1. The formation of radioisotopes in the crystal at proton irradiation has been analyzed. The formation of isotopes was also simulated with the help of the FLUKA package. The simulation was found to be in a good agreement with experimental results. The results have been used to estimate the expected intensity of parasitic radio-luminescence at high-luminosity operation in a GAGG/W sampling electromagnetic calorimeter.
关键词： Electromagnetic calorimetry,radiation damage,gadolinium-aluminum-gallium garnet,optical transmission,scintillation crystal
更新于2025-09-09 09:28:46