- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Enhanced Optical Communications Through Joint Time-Frequency Multiplexing Strategies
摘要： We present a power-efficient and reduced-complexity all-optical approach to generate high-bit rate superchannels, based on joint time-frequency multiplexing. Both optical orthogonal frequency division multiplexing (OFDM) and Nyquist-optical time division multiplexing (N-OTDM) signals are generated and processed using a wavelength-selective switch (WSS). We use the fractional Fourier transform (FrFT) to introduce the largest degree of flexibility in optical networking, and we experimentally demonstrate that the transmitted signal can be received either in parallel, as OFDM subcarriers, or in series, as an N-OTDM signal. Compared to conventional optical OFDM, we achieve peak to average power ratio (PAPR) flexible reduction; compared to N-OTDM, we introduce chromatic dispersion (CD) management. We successfully demonstrate a field trial experiment of 4-channel 40 Gb/s hybrid OFDM/N-OTDM transmission over the 89.2-km Japan gigabit network-extreme (JGN X) test bed, with 1 bit/s/Hz spectral efficiency.
关键词： optical Fourier transform,optical signal processing,Nyquist OTDM,OFDM,fractional Fourier transform
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) - An Insight into Pure Ge Based Kesterite Synthesis
摘要： The distributed Brillouin analysis of an 8.8-km-long ?ber with a spatial resolution of 2 cm is presented. All 440 000 potential resolution points are addressed in the measurement. A 7-cm-long hot-spot, located toward the output end of the pump wave, is properly identi?ed in the experiment. The experimental error in the estimate of the local values of the Brillouin frequency shift is ±3.5 MHz. The analysis is based on the simultaneous generation and analysis of Brillouin interaction in more than 2000 correlation peaks, induced by periodic phase modulation of the pump and signal waves. The Brillouin ampli?cations at individual peaks are resolved using radar-like coding of pump wave magnitude by a 10000 bit-long aperiodic sequence, and postdetection compression at the receiver end. Extensive numerical simulations of the Brillouin interactions over kilometers of ?ber with centimeter resolution are reported as well. The results are at the state of the art for high-resolution distributed Brillouin sensors.
关键词： sequence compression,All-optical signal processing,stimulated Brillouin scattering,?ber-optic sensors,distributed ?ber sensors,correlation-domain analysis
更新于2025-09-19 17:13:59
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[IEEE 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fukuoka, Japan (2019.7.7-2019.7.11)] 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - FMCW lidar with communication capability using phase-diversity coherent detection
摘要： Digital signals are encoded via amplitude modulation on the LFM optical signal of an FMCW lidar. The distance and data are simultaneously extracted without crosstalk. The data transmission is not influenced by the Doppler Effect.
关键词： Optical signal processing techniques for optical communications
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) - Integrated Photonic Filters for Flexible Analog-based Mobile Fronthauling
摘要： A Wavelength Division Multiplexing (WDM)-enabled analog mobile fronthaul architecture is presented supporting enhanced flexibility by exploiting the fine filtering properties of a fully reconfigurable, silicon photonics-based filtering element. The use of Photonic Integrated Circuit (PIC)-based elastic optical circuitries to support wavelength selectivity, reconfigurability and advanced signal processing at the optical edge is thoroughly discussed. Numerical studies are presented emphasizing on flexibility, low-energy consumption and the compatibility of our proposed PIC-based implementations with the analog Radio over Fiber (RoF)-based mobile transport schemes. Proof-of-concept analog photonic processing of 1 Gbaud Quadrature Phase Shift Keying (QPSK)- modulated radio through Intermediate Frequency over Fiber (IFoF) transmission experiments is successfully demonstrated.
关键词： analog optical signal processing,optical filters,silicon photonics,Analog radio-over-fiber,mobile fronthaul,wavelength division multiplexing,M-QAM
更新于2025-09-16 10:30:52
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[IEEE 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fukuoka, Japan (2019.7.7-2019.7.11)] 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Coherent WDM PON using a Single Time Lens Source and Kramers-Kronig Receiver
摘要： We demonstrate a coherent WDM-PON downstream transmission with a WDM transmitter based on optical Fourier transformation of a single-source TDM signal and a Kramers-Kronig receiver. 15 coherent WDM-PON signals are generated and transmitted over 100-km.
关键词： Optical communications,Subsystems and Advanced Functionality,Optical signal processing
更新于2025-09-16 10:30:52
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Fully Reconfigurable Waveguide Bragg Gratings for Programmable Photonic Signal Processing
摘要： Fiber Bragg gratings have been invented for over three decades and have been intensively employed in optical communications systems and sensor systems. The key limitation of a fiber Bragg grating is that once fabricated, it is hard to be tuned or with very limited tunability via thermal or mechanical tuning. Recently, great efforts have been directed into the study of realizing Bragg gratings on silicon-on-insulator (SOI) platform. The key advantage of Bragg gratings implemented based on SOI is that the gratings can be fast and electrically reconfigured with the use of free-carrier plasma dispersion effect in silicon, which can be employed for fast programmable photonic signal processing. In this paper, Bragg gratings based on SOI that are electrically programmable will be reviewed, and their use for advanced programmable optical and microwave signal processing will be discussed.
关键词： photonic integrated circuits,silicon photonics,Bragg gratings,optical signal processing,Microwave photonics
更新于2025-09-16 10:30:52
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[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - Neuromorphic Processing for Optical Communications
摘要： Neuromorphic computing has been recently demonstrated as a lucrative technology for communications systems. Optical neuromorphic technology enables implementation of machine learning algorithms in optical domain. We will discuss the recent progress, as well as, advantages and challenges of such technology for high speed and energy efficient signal processing.
关键词： optical signal processing,neuromorphic processing,fiber-optic communications,machine learning,neural networks
更新于2025-09-12 10:27:22
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Temperature extraction for Brillouin optical fiber sensing system based on extreme learning machine
摘要： The use of extreme learning machine (ELM) network to extract temperature distribution from the measured Brillouin gain spectra (BGSs) along the sensing fiber obtained by Brillouin optical fiber sensors is proposed and demonstrated experimentally. Compared with conventional curve fitting method (CFM), ELM network trained by a set of ideal BGSs can extract temperature information directly from the measured BGSs obtained by Brillouin optical time domain reflectometer (BOTDR) system without the need of determining Brillouin frequency shift (BFS) and converting BFS to temperature. The BGSs linewidth is taken into account to construct the ideal BGSs by using Pseudo-Voigt curve for ELM training. The performance of ELM is analyzed in detail and compared with that of widely-used Lorentzian CFM, and the experiment results show that ELM can provide higher accuracy even at large frequency scanning step and faster processing speed. Therefore, the proposed ELM approach is feasible and effective for temperature extraction in Brillouin optical fiber sensing system.
关键词： Nonlinear optical signal processing,Brillouin scattering,Temperature extraction,Optical fiber sensors,Extreme learning machine
更新于2025-09-12 10:27:22
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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) - Low Noise Optical Buffering Based on Non-Degenerate Phase Sensitive Parametric Amplification
摘要： Optical buffers are devices which can store optical signals for a period of time and could be valuable tools for applications such as optical storage, optical packet switching and all-optical signal processing providing the storage functionality in the optical domain, thus avoiding unwanted opto-electronic and eletro-optical conversions. During the last twenty years, there have been proposed many approaches for the implementation of optical buffers. The most straightforward scheme is the use of a fiber spool playing the role of a long-time optical delay line which requires either direct or indirect amplitude modulation to maintain the bit timing [1]. Other interesting techniques referring to optical buffering are slow-light [2], temporal solitons in optical cavities [3], excitability properties of optical devices [4] and photonic crystal nanocavities [5]. In this paper, a buffer relying on long-time optical delays supported by phase-sensitive amplification (PSA) is theoretically and numerically analysed. The scheme is compared against a buffer employing phase insensitive amplification (PIA). The buffer is studied for different levels of internal losses and in two configurations: the first considers that the PSA gain element precedes the source of losses whilst the second topology considers the opposite. Results derived from numerical simulations based on Nonlinear Schrodinger Equation (NLSE) solved with the use of split-step Fourier method taking into account polarization mode dispersion and quantum noise are also presented. The results show that the PSA enabled buffer is more robust to the accumulated noise attributed to multiple circulations in the optical cavity and can preserve the signal fidelity for hundreds of circulations, thus emerging as a promising long run buffering solution, being modulation format transparent and with the potential of multi-wavelength buffering as it will be shown in the context of the paper.
关键词： all-optical signal processing,noise figure,phase-sensitive amplification,optical storage,optical buffering
更新于2025-09-11 14:15:04
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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) - Zero-Birefringence Silicon Slot Waveguides with L-Rails
摘要： Silicon slot waveguides are widely used for photonic sensing [1] and optical signal procesing [2]. We propose a novel slot formed when a sub-micron rib waveguide is slit with vertical symmetry resulting in L shaped rails to have Zero Birefringence (ZB). This geometry gives the flexibility to choose the slab (strip-load) region for doping or modulation. Index modulation of the slab sidewall offers platform for Bragg gratings with sub-nanometer stop bands [3,4]. We show that slots with L-rails possess better confinement and higher tolerance to sidewall width variations compared to strip-rails [5] and ZB can be achieved by engineering the waveguide geometry. Optimal waveguide-dimensions at a wavelength λ = 1550 nm are designed from modal analysis through full-vectorial computations.
关键词： Zero Birefringence,optical signal processing,Silicon slot waveguides,photonic sensing,L-rails
更新于2025-09-11 14:15:04