Article
Engineering, Electrical & Electronic
Peihong Li, Yu Wang, Xin Liu, Qing Bai, Yan Gao, Hongjuan Zhang, Baoquan Jin
Summary: A modulation scheme based on phase coding is proposed in this paper to suppress the amplitude distortion after optical amplification, addressing the issue of transient effect in erbium-doped fiber amplifier (EDFA) that restricts the application of phase-sensitive optical time-domain reflectometry (f-OTDR) in long-distance vibration sensing. The scheme utilizes Quadrature Phase-Shift Keying (QPSK) with high spectrum utilization efficiency, and the use of random sequence coding probe pulse improves the signal-to-noise ratio (SNR) without loss of sensing bandwidth. Experimental results demonstrate the effectiveness of the scheme.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Qiankun Li, Xiongwei Yang, Qi Xu, Jiali Yang, Yameng Li, Huajun Yang
Summary: An all-optical aggregation and de-aggregation scheme is proposed and simulated based on nonlinear effects in high nonlinear fiber, allowing conversion between OOK, QPSK, and 8QAM signals. In the de-aggregation process, the 30 Gbit/s 8QAM signal is converted into a 20 Gbit/s QPSK signal and a 10 Gbit/s BPSK signal using SPM, XPM, FWM, and PA effects. The converted OOK signal is obtained through vector superposition, while in the aggregation process, the QPSK and OOK signals are aggregated into a 30 Gbit/s 8QAM signal again using XPM and PA effects. The proposed scheme is important for network traffic aggregation and de-aggregation with different modulation formats.
OPTICAL FIBER TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Xinxin Gao, Ze Gu, Qian Ma, Wen Yi Cui, Tie Jun Cui, Chi Hou Chan
Summary: Driven by the demands for compact interconnects and fast information transfer, research on spoof plasmonic metamaterials has been focused on achieving individual modulation of amplitude or phase at single frequencies due to structural limitations. This study proposes and experimentally demonstrates an ultra-thin reprogrammable modulator consisting of a spoof surface plasmonic polariton (SSPP) waveguide and spoof localized surface plasmon (SLSP) resonators, allowing independent control of amplitude and phase of surface waves. By manipulating the SSPP waveguide and SLSP resonators in real-time, various programmable modulations such as amplitude-shift keying, phase-shift keying, quadrature amplitude modulation, and frequency-shift keying can be achieved. Measurement results confirm the potential applications of the reprogrammable plasmonic metamaterial in integrated circuits and communication systems.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Engineering, Multidisciplinary
Bochao Kang, Xu Li, Yangyu Fan, Jian Zhang, Dong Liang, Yongsheng Gao
Summary: This paper proposes a novel optical method for implementing broadband microwave DFS measurement, achieving simultaneous estimation of DFS signals and direction to avoid low-frequency interference. The experiment demonstrates the advantages of the method in system stability and frequency range.
Article
Engineering, Electrical & Electronic
Bipin K. Saw, Vijay Janyani, Ghanshyam Singh
Summary: In this paper, the authors propose an adaptive PPM-GMSK-SIM system over F distribution channel model with pointing error. The system adapts the modulation order according to atmosphere turbulence (AT) and achieves better performance in ABER and spectral efficiency compared to the PPM-MSK-SIM system. The improvement in ABER performance is approximately 6 dB at ABER value is 10(-3) in weak, moderate, and strong atmospheric turbulence conditions. The system performance improves about 11 dB at SNR value is 10(-3) when compared to the adaptive PPM-MSK-SIM system.
OPTICAL AND QUANTUM ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Inho Ha, Joungmoon Lee, Jinwoo Park, Sang-Kook Han
Summary: This study proposes a novel multi-dimensional optical transmission system based on a direct detection system, which utilizes modulation techniques based on optical intensity, polarization, and phase to achieve optical multi-dimensional transmission. The performance and interference of each dimension modulation were analyzed through numerical and experimental analysis. The system's performance was verified using BER, eye diagram, and spectrum analysis.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Liang Lv, Yi Fang, Lin Dai, Yonghui Li, Mohsen Guizani
Summary: This paper proposes a new protograph low-density parity-check (PLDPC) coded generalized spatial multipulse position modulation (GSMPPM) system for reliable and efficient transmissions in free-space optical (FSO) communication over weak turbulence channels. The proposed system incorporates novel GSMPPM constellations called asymmetric dual-mode (ADM) constellations, which intelligently integrate generalized space shift keying (GSSK) modulation with MPPM, to improve the performance of PLDPC-coded GSMPPM system. Additionally, an improved PLDPC code, referred to as I-PLDPC code, is constructed using a protograph extrinsic information transfer (PEXIT) algorithm, which outperforms existing PLDPC codes in weak turbulence channels. Analytical and simulation results demonstrate that the proposed ADM constellations and I-PLDPC code achieve notable performance gains. Therefore, the proposed PLDPC-coded GSMPPM system with ADM constellations is capable of meeting the high-reliability requirement for FSO applications.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2023)
Article
Optics
Hassan Termos, Ali Nansour
Summary: This study focuses on a novel concept of transmitting QPSK modulation through electro-optical frequency up-conversion using cascaded MZMs. The design and operating regime peculiarities of the MZMs used as a sampling up-converter mixer in a RoF system are analyzed. Simulation and experimental results show similar behavior, and the conversion gain of the cascaded MZMs link decreases with increasing mixing frequency.
Article
Computer Science, Information Systems
Binyu Li, Haifeng Yao, Lei Zhang, Shoufeng Tong
Summary: A cascaded LMS-LMS adaptive equalization scheme is proposed to improve the transmission performance of QPSK modulated optical signals in medium and weak turbulence channels. The scheme is shown to effectively increase transmission rate and reduce bit-error ratio under different turbulence conditions through simulations and experiments.
Article
Computer Science, Information Systems
Yupeng Li, Yichao Zhang, Lei Li, Mingzhu Zhang, Qianqian Li, Du Wu, Xiaoming Ding, Xiaocheng Wang
Summary: This paper studies a novel encoding rule and compensation scheme for 32-Point 6PolSK-QPSK modulation by classifying symbols to further improve the transmission rate of the signal system. The simulation results show that the error performance of 2.6 dB and 8.7 dB are improved for unrevised and revised data transmission, compared with the 32-Point 6PolSK-QPSK signal scheme obtained by rotating PM-QPSK.
Article
Engineering, Electrical & Electronic
Mohammed Al-Ansi, Syed Alwee Aljunid, Essam Sourour, M. S. Anuar, C. B. M. Rashidi
Summary: Inspired by the advantages of non-orthogonal multiple access, spatial modulation, and space shift keying, this research designs amalgamation models that combine these technologies. The models are classified based on the number of RF chains into multi-RF and single-RF models. A spectral-efficient multi-RF model and a new energy-efficient single-RF model are proposed. The results show that the multi-RF model achieves high spectral efficiency, while the single-RF model provides flexibility in trading off different features.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2022)
Article
Computer Science, Information Systems
Peng Kang, Ziqiang Zhu, Zhijian Lin, Pingping Chen, Yong Li
Summary: In this letter, a scheme combining pulse position modulation (PPM) and permutation index differential chaos shift keying (PI-DCSK) modulation is proposed to improve data rate and performance. The proposed scheme is shown to outperform existing DCSK-based schemes, and its superiority and feasibility are demonstrated in multipath Rayleigh fading channels and typical ultra-wideband channels.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Kyo Inoue
Summary: This paper analyzes the impact of inter-channel crosstalk on QPSK and QAM signals in multichannel optical systems, finding that as the number of channels increases, the BER degradation caused by crosstalk light approaches that caused by Gaussian noise light, and the degradations caused by crosstalk light and Gaussian light are similar for high-level modulation QAM signals.
IEICE TRANSACTIONS ON COMMUNICATIONS
(2021)
Article
Optics
Xu Hua Cao, Xiao Jie Fan, Ming Li, Ning Hua Zhu, Wei Li
Summary: In this study, we propose a novel photonic approach to generate reconfigurable multi-frequency multiple binary modulation formats microwave signals using a dual-polarization dual-drive Mach-Zehnder modulator. By setting the proper formats of coding signals, various modulation formats of microwave signals can be generated successfully without changing the system structure.
OPTICS COMMUNICATIONS
(2024)
Article
Chemistry, Analytical
Yanxia Sun, Chikomborero Shambare, OdunAyo Imoru
Summary: QPSK is a digital modulation technique used in OFDM systems. This paper proposes a hybrid algorithm combining wind-driven optimization and genetic algorithm to address the phase ambiguity and bit error problems in transmission.
Article
Engineering, Electrical & Electronic
Shen Li, Ali Mirani, Magnus Karlsson, Erik Agrell
Summary: This paper presents the design of low-complexity Voronoi constellations (VCs) with a cubic coding lattice and pseudo-Gray labeling, which achieve considerable shaping gains and provide finer spectral efficiency choices compared to conventional VCs. The proposed VCs also have higher information rates due to their inherently good pseudo-Gray labeling feature and lower decoding complexity.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Ping Zhao, Magnus Karlsson, Peter A. Andrekson
Summary: Low-noise optical amplifiers like compact, waveguide-based, parametric amplifiers utilizing four-wave mixing process have been pursued. An analytic model for phase-sensitive parametric amplifiers based on nonlinear optical waveguides is presented, considering the impact of linear loss. Si3N4 waveguides show potential for achieving 28 dB gain with a 0.8 dB noise figure, with research focusing on improving performance through cross-section design.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Georg Rademacher, Ruben S. Luis, Benjamin J. Puttnam, Roland Ryf, Sjoerd van der Heide, Tobias A. Eriksson, Nicolas K. Fontaine, Haoshuo Chen, Rene-Jean Essiambre, Yoshinari Awaji, Hideaki Furukawa
Summary: This paper compares the use of 3-mode few-mode fibers and 3-core coupled-core multi-core fibers in space-division multiplexed transmission systems. The analysis shows that the coupled-core multi-core fiber achieves higher data rates at shorter transmission distances.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Ping Zhao, Zhichao Ye, Magnus Karlsson, Victor Torres-Company, Peter A. Andrekson
Summary: This paper reports a low-noise optical phase-sensitive amplifier (PSA) enabled by a single compact integrated silicon nitride photonic waveguide, which allows optical signal processing at different wavelengths. The experimental results show that silicon-nitride-based PSAs are promising for the next generation of broadband optical signal processing and communication systems.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
Sjoerd van der Heide, Ruben S. Luis, Sebastiaan Goossens, Benjamin J. Puttnam, Georg Rademacher, Ton Koonen, Satoshi Shinada, Yoshinari Awaji, Alex Alvarado, Hideaki Furukawa, Chigo Okonkwo
Summary: A software-defined optical receiver implemented on a commercial graphics processing unit (GPU) is capable of processing various orders of quadrature amplitude modulation (QAM) signals, and its performance is validated over a 91 km fiber link.
Review
Chemistry, Analytical
Krishna Twayana, Israel Rebolledo-Salgado, Ekaterina Deriushkina, Jochen Schroder, Magnus Karlsson, Victor Torres-Company
Summary: This review paper provides an overview of the latest advancements in linear interferometric techniques using laser frequency comb sources. Various techniques including Fourier transform spectroscopy, linear spectral interferometry and swept-wavelength interferometry are extensively discussed. The unique features enabled by laser frequency comb sources are demonstrated, along with specific applications in molecular spectroscopy, optical coherence tomography, and the characterization of photonic integrated devices and components. Lastly, the potential possibilities offered by advancements in chip-scale swept sources and frequency combs are explored.
Article
Engineering, Electrical & Electronic
Mehdi Jahed, Alexander Caut, Jeroen Goyvaerts, Marc Rensing, Magnus Karlsson, Anders Larsson, Gunther Roelkens, Roel Baets, Peter O'Brien
Summary: This study investigates the angled flip-chip integration of a singlemode 850 nm VCSEL on a silicon nitride PIC. The conditions for high coupling efficiency and low optical feedback are examined using numerical simulations. Experimental results show that increasing the angle decreases the coupling efficiency and optical feedback, and co-directional coupling introduces first-order diffraction loss and further reduces the coupling efficiency.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
Ilaria Cristiani, Cosimo Lacava, Georg Rademacher, Benjamin J. Puttnam, Ruben S. Luis, Cristian Antonelli, Antonio Mecozzi, Mark Shtaif, Daniele Cozzolino, Davide Bacco, Leif K. Oxenlowe, Jian Wang, Yongmin Jung, David J. Richardson, Siddharth Ramachandran, Massimiliano Guasoni, Katarzyna Krupa, Denis Kharenko, Alessandro Tonello, Stefan Wabnitz, David B. Phillips, Daniele Faccio, Tijmen G. Euser, Shangran Xie, Philip St J. Russell, Daoxin Dai, Yu Yu, Periklis Petropoulos, Frederic Gardes, Francesca Parmigiani
Summary: Multimode devices and components have garnered significant attention in recent years, opening up new possibilities for designing more complex and sophisticated optical components. By utilizing different modes of propagation, these devices can increase fiber optic capacity, introduce novel intermodal interactions, and allow for complex manipulation of optical modes to cater to various applications.
Article
Engineering, Electrical & Electronic
Zonglong He, Jinxiang Song, Kovendhan Vijayan, Christian Hager, Alexandre Graell i Amat, Henk Wymeersch, Peter A. Andrekson, Magnus Karlsson, Jochen Schroder
Summary: The study demonstrates a novel size reduction approach for LUT digital predistortion, minimizing storage memory requirements while maintaining performance for high-order modulation formats. Additionally, a neural network-based nonlinear predistortion technique is proposed, showcasing consistent performance across various constellations.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Mohammad Farsi, Magnus Karlsson, Erik Agrell
Summary: This paper characterizes the capacity of the polarization drift channel with imperfect channel knowledge under an average power constraint for the first time. It presents an achievable information rate (AIR) that is highly dependent on the channel estimation technique and shows that a tighter lower bound can be achieved with a unitary estimation of the channel. Additionally, a data-aided channel estimator based on the Kabsch algorithm is proposed, which outperforms the least-square error algorithm in terms of AIR.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Zexin Chen, Zonglong He, Ali Mirani, Jochen Schroder, Peter Andrekson, Magnus Karlsson, Meng Xiang, Yu Yu, Ming Tang, Yuwen Qin, Songnian Fu
Summary: Probabilistic constellation shaping (PCS) provides unprecedented flexibility for future optical networks, but it demands more from the transmitter when combined with higher-order modulation formats and higher symbol rates. In this study, we investigate the impact of transmitter impairments on probabilistically shaped quadrature amplitude modulation (PS-QAM) signals and propose an optimization strategy to mitigate the impairments. The results show that the optimized parameters mainly depend on the noise from the transmitter and are insensitive to the noise from the fiber optical link and the shaping factor.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Shen Li, Ali Mirani, Magnus Karlsson, Erik Agrell
Summary: This paper examines the performance of 16- and 32-dimensional Voronoi constellations (VCs) with various spectral efficiencies in the nonlinear fiber channel. Different signal processing schemes, including chromatic dispersion compensation and digital backpropagation, are considered for the transmission of VCs in both single-channel and wavelength-division multiplexing systems. The performance metrics of VCs, such as uncoded bit error rate, mutual information (MI), and generalized mutual information (GMI), are evaluated. Compared to quadrature amplitude modulation (QAM) formats, VCs exhibit significant advantages in terms of launch power gains, MI gains, potential reach increase, and GMI gains.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Ekaterina Deriushkina, Israel Rebolledo-Salgado, Mikael Mazur, Victor Torres-Company, Peter Andrekson, Jochen Schroeder, Magnus Karlsson
Summary: This paper presents an experimental scheme that combines swept-wavelength interferometry and dual-comb spectroscopy to overcome their limitations. By using a tunable laser source to sweep over the frequency comb spacing and capture all intermediate frequencies, full-field broadband measurements over 1.25 THz comb bandwidth with increased frequency resolution are demonstrated.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Mohammad Farsi, Christian Hager, Magnus Karlsson, Erik Agrell
Summary: This paper analyzes the effectiveness of polarization tracking algorithms in optical transmission systems undergoing fast state of polarization rotations and polarization-dependent loss. The proposed algorithms demonstrate higher robustness to SOP and PDL drift compared to GD-based algorithms, making them promising candidates for use in aerial fiber links.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Georg Rademacher, Ruben S. Luis, Benjamin J. Puttnam, Juan Carlos Alvarado Zacarias, Rodrigo Amezcua-Correa, Kazuhiko Aikawa, Yoshinari Awaji, Hideaki Furukawa
Summary: We experimentally investigated the utilization of distributed Raman amplification in a graded-index three-mode fiber, achieving a signal bandwidth of over 80 nm. By pumping only the highest-order modes, we measured a gain of up to 6 dB with a mode-dependence of 0.3 dB.
2022 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)
(2022)
