- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Comparison of Optical Single Sideband Techniques for THz-over-fiber Systems
摘要： The use of single sideband (SSB) signals and envelope detection is a promising approach to enable the use of economic free-running lasers in photonic THz communications. To combat the signal-signal beat interference (SSBI) associated with envelope detection, broad guard bands (GBs) may be used given the large unregulated spectrum available at THz frequencies (100 GHz – 10 THz). In this scenario, the conventional way of generating SSB signals through a digital SSB filter (here referred to as the CSSB scheme) would require quite high analog digital-to-analog converter (DAC) bandwidths. Digital virtual SSB (DVSSB) and analog virtual SSB (AVSSB) have been proposed in direct-detection optical systems for relaxing the DAC bandwidth requirements. In this paper, we compare the three techniques through simulations and implement them, for the first time, in a THz-over-fiber (ToF) system operating at 250 GHz. For the transmission experiments we employ 5 GBd 16-QAM signals with three different GBs (5.5 GHz, 4.75 GHz and 3.5 GHz). The simulations show that the best performance is obtained with the AVSSB technique, while the worst is obtained with the DVSSB scheme, where the quality of the generated sideband degrades with carrier-to-sideband power ratio. In the experimental transmissions, where receiver noise was the main source of noise, similar behavior was found between the three techniques. At the 3.5 GHz GB, however, the DVSSB exhibited a penalty of 1 dB with respect to the other two. This is likely to be due to nonlinear distortions caused by the increase in the virtual tone power.
关键词： microwave photonics,Broadband communication,semiconductor lasers,photonic integrated circuits,digital signal processing,envelope detectors,optical mixing,millimeter wave communication
更新于2025-09-04 15:30:14
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[IEEE 2018 19th International Conference of Young Specialists on Micro/Nanotechnologies and Electron Devices (EDM) - Erlagol (Altai Republic), Russia (2018.6.29-2018.7.3)] 2018 19th International Conference of Young Specialists on Micro/Nanotechnologies and Electron Devices (EDM) - Multifunctional Magnetophotonic Structure Creation Based on Magnetic Properties of Micro and Nanoscale Clusters
摘要： The optical and magnetic properties, phenomena and effects of nano- and microparticles of clusters and other formations can potentially influence the propagation and processing of optical signals in magnetophotonic structures. The analysis of existing devices and the ones proposed for interpretation of their implementation allows the correct operation algorithm in correlation to structural characteristics and to multi-functional magnetophotonic structures of micro- and nanoscale. The magnetophotonic structure models are considered and analyzed, which makes it possible to find the correct approaches for their implementation. The choice of the specific magnetophotonic medium for a functional simulator is determined by the requirements of functional orientation, simplicity and efficiency, manufacturability and other factors.
关键词： nanoclusters,magnetic phase transitions,superparamagnetism,Photonics,resonance
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE Photonics Conference (IPC) - Reston, VA (2018.9.30-2018.10.4)] 2018 IEEE Photonics Conference (IPC) - Low Latency PON and RoF for 5G Wireless Systems
摘要： We review optical access technology candidates for 5G wireless systems requiring low latency as well as high transmission bandwidth. Recent feasibility studies with next generation PON prototype and analog transmission are discussed.
关键词： 5G,25G PON,Low latency,Microwave Photonics
更新于2025-09-04 15:30:14
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MEMS-based Tunable Grating Coupler
摘要： We demonstrate a microelectromechanical-system-based tunable grating coupler capable of changing the central wavelength. The grating structure is fabricated on a suspended cantilever with supporting arms and can be tuned by an applied voltage. We demonstrate a tunable range of 22.8 nm under actuation voltages of up to 12 V in the present devices. In addition, we show that the supporting arms are critical components that can be used to effectively avoid the pull-in effect.
关键词： MEMS-based tunable grating,Silicon photonics,grating coupler
更新于2025-09-04 15:30:14
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Wide Bandgap Phase Change Material Tuned Visible Photonics
摘要： Light strongly interacts with structures that are of a similar scale to its wavelength, typically nanoscale features for light in the visible spectrum. However, the optical response of these nanostructures is usually fixed during the fabrication. Phase change materials offer a way to tune the properties of these structures in nanoseconds. Until now, phase change active photonics has used materials that strongly absorb visible light, which limits their application in the visible spectrum. In contrast, Sb2S3 is an underexplored phase change material with a bandgap that can be tuned in the visible spectrum from 2.0 to 1.7 eV. This tuneable bandgap is deliberately coupled to an optical resonator such that it responds dramatically in the visible spectrum to Sb2S3 reversible structural phase transitions. It is shown that this optical response can be triggered both optically and electrically. High-speed reprogrammable Sb2S3 based photonic devices, such as those reported here, are likely to have wide applications in future intelligent photonic systems, holographic displays, and microspectrometers.
关键词： active photonics,phase change materials,optical resonator,structural color,bandgap
更新于2025-09-04 15:30:14
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Controlling light in Airy and higher-order caustic photonic structures
摘要： Caustics form geometrically stable structures in light and are hierarchically categorized by the catastrophe theory. We embed higher-order cusp and swallowtail catastrophes in paraxial beams and investigate their dynamics. Utilizing high-intensity caustics that propagate on curved trajectories, we realize photonic caustic lattices in photosensitive media, and demonstrate waveguiding with a rich diversity of light guiding paths.
关键词： caustics,photonic structures,waveguiding,catastrophe theory,nonlinear photonics
更新于2025-09-04 15:30:14
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Electronically programmable photonic molecule
摘要： Physical systems with discrete energy levels are ubiquitous in nature and are fundamental building blocks of quantum technology. Realizing controllable artificial atom- and molecule-like systems for light would enable coherent and dynamic control of the frequency, amplitude and phase of photons. In this work, we demonstrate a ‘photonic molecule’ with two distinct energy levels using coupled lithium niobate microring resonators and control it by external microwave excitation. We show that the frequency and phase of light can be precisely controlled by programmed microwave signals, using concepts of canonical two-level systems including Autler–Townes splitting, Stark shift, Rabi oscillation and Ramsey interference. Through such coherent control, we show on-demand optical storage and retrieval by reconfiguring the photonic molecule into a bright–dark mode pair. These results of dynamic control of light in a programmable and scalable electro-optic system open doors to applications in microwave signal processing, quantum photonic gates in the frequency domain and exploring concepts in optical computing and topological physics.
关键词： topological physics,coherent control,optical computing,microring resonators,lithium niobate,optical storage,microwave excitation,photonic molecule,quantum photonics
更新于2025-09-04 15:30:14