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
Optics
Ruihuan Zhang, Xingfeng Li, Yu He, Gang Chen, Liangming Xiong, Haoshuo Chen, Nicolas K. Fontaine, Yong Zhang, Weiqiang Xie, Yikai Su
Summary: This article proposes a multimode coupling solution based on a rectangular core few-mode fiber and an integrated multimode coupler to achieve high bandwidth-density optical interconnects. Through corresponding experiments, a bandwidth density of up to 19.4 Tb s mm -1 is achieved at the chip facet, with the DSP power consumption controlled below 6% of a conventional system.
LASER & PHOTONICS REVIEWS
(2023)
Article
Engineering, Electrical & Electronic
Sumaiya Akhtar Mitu, Lway Faisal Abdulrazak, Kawsar Ahmed, Youssef Trabelsi, Fahad Ahmed al Zahrani, M. S. Mani Rajan
Summary: A multi-mode supported elliptical ring core fiber is demonstrated in this study, which is favorable for mode division multiplexing and Internet of Things (IoT) communications. The investigated fiber structure has low crosstalk and high sensitivity response, making it important for the development of optical communications and IoT technologies.
INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS
(2022)
Article
Engineering, Electrical & Electronic
Yuto Sagae, Taro Iwaya, Takayoshi Mori, Taiji Sakamoto, Takashi Matsui, Kazuhide Nakajima
Summary: The characteristics of crosstalk (XT) noise-to-signal ratio in a distributed Raman amplifier (DRA) for bi-directional multi-core fiber (MCF) transmission are investigated. A model is proposed to calculate XT noise by considering the noise contribution from Rayleigh scattering. The validity of the model is verified numerically and experimentally. The model reveals that the XT noise-to-signal ratio varies with the on-off gain, providing a way to minimize XT noise while maintaining a net gain of less than 0 dB.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Tetsuya Hayashi, Taiji Sakamoto, Yusuke Yamada, Roland Ryf, Rene-Jean Essiambre, Nicolas Fontaine, Mikael Mazur, Haoshuo Chen, Takemi Hasegawa
Summary: Randomly-coupled multi-core fiber (MCF) technology has gained attention for its applicability in long-haul transmission systems. Compared to weakly-coupled MCFs, randomly-coupled MCFs can achieve higher spatial channel density and lower transmission loss using existing single-mode fiber core designs. This article provides an overview of the advancements in randomly-coupled MCF technology, including its classification, design, optical property characterization methods, and performance improvements in transmissions.
PROCEEDINGS OF THE IEEE
(2022)
Article
Engineering, Electrical & Electronic
Jing Zhang, Yunkang Chen, Zhichao Wu, Shijie Feng, Perry Shum, Tianye Huang
Summary: This paper introduces a uniquely designed few-mode fiber that can support multiple polarization modes and adjustable chromatic dispersion. The separation of adjacent guided modes is achieved through stress-rods-induced birefringence and high refractive index difference, providing a new way to regulate dispersion.
OPTICAL FIBER TECHNOLOGY
(2022)
Article
Optics
Komal Ojha, Darpan Mishra, Kumar Appaiah, Deepak Jain
Summary: This study investigates the use of graded-index few-mode fiber (GI-FMF) for mode-division-multiplexed transmission with a 4-LP-mode fiber. The GI-FMF is optimized for large effective indices differences (Delta n(eff)) and low differential mode delay (DMD) between LP modes by adjusting profile parameters, refractive index differences, and core radius. The optimized parameters for weakly-coupled WC-GI-FMF and strongly-coupled SC-GI-FMF are reported, demonstrating the potential of GI-FMF for various applications. The narrow air trench-assisted SC-GI-FMF is also explored to further reduce DMD.
Article
Optics
Pengfei Tian, Weihong Bi, Xiaoyu Wang, Wa Jin, Baojun Zhang, Xinghu Fu, Guangwei Fu
Summary: This paper introduces a new type of long period fiber grating mode converter based on hybrid dual-core fiber, which can convert LP01 mode to LP21 and LP02 with purity up to 98% after conversion.
Article
Materials Science, Multidisciplinary
Haoyang Ren, Yingning Wang, Wenpu Geng, Wenqian Zhao, Runzhou Zhang, Zhongqi Pan, Yang Yue
Summary: This paper presents a design of a multi-ring air-core trench-assisted fiber that supports transmission over the entire C + L band with low inter-ring crosstalk. The effects of the ring spacing, wavelength range, and doping concentration on the crosstalk suppression are systematically investigated. The complexity of the MIMO processing system is greatly reduced with a fewer-optical-core structure while keeping low inter-ring crosstalk.
RESULTS IN PHYSICS
(2023)
Article
Optics
Rabiu Imam Sabitu, Nafizah Goriman Khan, Amin Malekmohammadi
Summary: This paper reports on mode conversion using tilted few-mode fiber assisted by dual arc waveguide. A multilayer core multimode fiber is used for modeling the device. The optimized device achieves high efficiency conversions between different modes, making it suitable for mode-division multiplexing communication.
Article
Optics
Yuxin Ding, Shuguang Li, Jianshe Li, Huijing Du, Xiaokai Wang, Ying Guo, Xiaojian Meng, Xinxin Ma, Yujun Wang, Yuanyuan Zhao
Summary: In this paper, a new structure of high-quality few-mode core and tapered single-mode core is proposed to design a six-spatial-mode multiplexer. By optimizing the parameters, efficient mode coupling effect and good tolerance ability are achieved. Numerical calculation results show that the average coupling efficiencies of different modes in the mode multiplexer are all greater than 90% in the S+C+L band.
Article
Engineering, Electrical & Electronic
Yingning Wang, Yuanpeng Liu, Wenqian Zhao, Jian Yang, Wenpu Geng, Yuxi Fang, Changjing Bao, Yongxiong Ren, Zhi Wang, Yan-ge Liu, Zhongqi Pan, Yang Yue
Summary: This paper designs and analyzes a multi-ring-air-core fiber supporting thousands of OAM modes, and investigates the tradeoffs between ring number/density and system performance parameters. Based on the analytical results, the fiber has high transmission rate and spectrum efficiency, and shows great potential for various applications in optical communication systems.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
Mingqing Zuo, Dawei Ge, JiaXin Liu, Yuyang Gao, Lei Shen, Xiaobo Lan, Zhangyuan Chen, Yongqi He, Juhao Li
Summary: This paper proposes an intermodal-MIMO-free MDM transmission scheme based on weakly coupled multiple-ring-core FMF, which achieves long-haul FMF transmission by reducing intermodal crosstalk. The feasibility of the scheme is verified through simulations and experiments, providing possibilities for practical applications of long-haul MDM techniques.
Article
Engineering, Electrical & Electronic
Yingjuan Ci, Fang Ren, Xiao Lei, Yanfei Zhang, Xiaohui Wang, Jianping Wang
Summary: We propose a weakly-coupled air-hole-bow-tie-assisted few-mode fiber (AH-BT-FMF) that supports 26 eigenmodes across the C + L band for short-haul communication systems. By introducing an elliptical core, air holes, and a bow-tie stress-applying area, we effectively split adjacent eigenmodes. We evaluate the fiber's parameters and investigate its broadband performance, including the effective refractive index difference, differential mode delay, dispersion, and effective area.
OPTICAL AND QUANTUM ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Jiajing Tu, JinPei Li, Tianjin Wen, Yongguang Xiao, Quanchao Lu, Jianye Zhao, Yingyu Chen, Hanyu Gao, Lei Shen, Lei Zhang, Liubo Yang, Wei Li, Cheng Du, Shecheng Gao, Xingwen Yi, Weiping Liu, Zhaohui Li
Summary: This study focuses on OAM mode supporting few-mode RCF solutions for submarine cables and proposes a 3-OAM-MG RCF with a core-cladding index contrast of 0.6%. Experimental results demonstrate the potential application of this transmission system in a long-haul submarine cable system.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Georg Rademacher, Benjamin J. Puttnam, Ruben S. Luis, Jun Sakaguchi, Werner Klaus, Tobias A. Eriksson, Yoshinari Awaji, Tetsuya Hayashi, Takuji Nagashima, Tetsuya Nakanishi, Toshiki Taru, Taketoshi Takahata, Tetsuya Kobayashi, Hideaki Furukawa, Naoya Wada
Summary: This study demonstrated high capacity transmission in a multi-core fiber, achieving data rates over 10.66 Pb/s with single optical comb source. It highlighted the impact of mode-dependent loss on achievable data rates within cores, while also exploring the potential for multi-span transmission over the same fiber with performance penalties due to sub-optimal transmission components.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Optics
Tetsu Morishima, Ken Manabe, Shuhei Toyokawa, Tetsuya Nakanishi, Tomomi Sano, Tetsuya Hayashi
Summary: The novel single-MCF connector achieves rotational fiber alignment and ferrule floating by using standard MU ferrule and modified LC housing. Connectors with an average loss of 0.07 dB passed tests, with numerical simulations confirming suppression of ferrule rotation from external forces.
Article
Optics
Tetsuya Hayashi
Summary: The use of bidirectional multi-core fiber (MCF) transmissions suppresses inter-core crosstalk and improves signal quality and/or core density compared to unidirectional transmissions. This paper derives approximate expressions for Rayleigh backscattered inter-core crosstalk and discusses their accuracy.
Article
Computer Science, Hardware & Architecture
Ruben S. Luis, Benjamin J. Puttnam, Georg Rademacher, Satoshi Shinada, Tetsuya Hayashi, Tetsuya Nakanishi, Yuki Saito, Tetsu Morishima, Hideaki Furukawa
Summary: This study demonstrates the use of spatial division multiplexing (SDM) to implement spine-leaf datacenter network topologies. Two possible scenarios are considered. The first scenario utilizes high-capacity multicore fiber interconnects, achieving a combined throughput of 12.8 Tb/s. The second scenario utilizes multicore fiber interconnects to establish multiple connections between pairs of spin-leaf switches, reducing the number of cables required.
JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING
(2023)
Article
Optics
Yuto Kobayashi, Tetsuya Hayashi
Summary: We quantitatively discuss the impact of core-dependent loss (CDL) on multicore fiber (MCF) crosstalk (XT). Within practical ranges of XT and CDL, CDL does not significantly affect power coupling coefficients and XT between cores. Therefore, considering the CDL-induced signal attenuation difference among cores is sufficient when evaluating the signal-to-XT ratio in MCFs with CDL. We also analyze the effects of CDL on XT measurements and find that the CDLs induced in an MCF as a measurement target and a measurement setup can be canceled by switching the source and destination cores of the XT, using the geometric mean of linear values or arithmetic mean of decibel values.
Article
Engineering, Electrical & Electronic
Tetsuya Hayashi, Taiji Sakamoto, Yusuke Yamada, Roland Ryf, Rene-Jean Essiambre, Nicolas Fontaine, Mikael Mazur, Haoshuo Chen, Takemi Hasegawa
Summary: Randomly-coupled multi-core fiber (MCF) technology has gained attention for its applicability in long-haul transmission systems. Compared to weakly-coupled MCFs, randomly-coupled MCFs can achieve higher spatial channel density and lower transmission loss using existing single-mode fiber core designs. This article provides an overview of the advancements in randomly-coupled MCF technology, including its classification, design, optical property characterization methods, and performance improvements in transmissions.
PROCEEDINGS OF THE IEEE
(2022)
Article
Optics
Jun Sakaguchi, Yoshinari Awaji, Hideaki Furukawa
Summary: This paper achieves the distributed optical reference over a distance of 12,600 km while maintaining low-noise characteristics, using an ultra-narrow-linewidth laser as a reference source and a fiber Bragg grating filter for noise removal. The distributed optical reference enables 10 GBaud, 5 wavelength-division-multiplexed dual-polarization 64QAM data transmission without using carrier phase estimation, significantly reducing off-line signal processing time.
Proceedings Paper
Optics
Masato Yoshida, Toshihiko Hirooka, Nakazawa Masataka, Tetsuya Hayashi, Takemi Hasegawa, Kohei Nakamura, Takanori Inoue
Summary: This paper presents a method for precise distributed measurement of mode-coupling using a multi-channel OTDR on a 60 km long 4-core fiber (4CF) for submarine transmission. By evaluating the crosstalk values separately in the fan-in/out devices and 4CF with a dynamic range of up to 85 dB, the effectiveness of the method is demonstrated.
2022 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)
(2022)
Proceedings Paper
Optics
Georg Rademacher, Ruben S. Luis, Benjamin J. Puttnam, Giammarco Di Sciullo, Robert Emmerich, Nicolas Braig-Christophersen, Andrea Marotta, Lauren Dallachiesa, Roland Ryf, Antonio Mecozzi, Colja Schubert, Pierre Sillard, Frank Achten, Giuseppe Ferri, Jun Sakaguchi, Cristian Antonelli, Hideaki Furukawa
Summary: This paper characterizes the first field-deployed 15-mode fiber cable and evaluates its differential mode delay and mode dependent loss over two distances. The results confirm the field-usability of the cable, as both quantities are sufficiently low.
2022 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)
(2022)
Proceedings Paper
Optics
Georg Rademacher, Ruben S. Luis, Benjamin J. Puttnam, Nicolas K. Fontaine, Mikael Mazur, Haoshuo Chen, Roland Ryf, David T. Neilson, Daniel Dahl, Joel Carpenter, Pierre Sillard, Frank Achten, Marianne Bigot, Jun Sakaguchi, Hideaki Furukawa
Summary: This work presents a technology that achieves a data transmission rate of 1.53 peta-bit/s over a 55-mode fiber, using low-loss, high mode-selectivity mode-multiplexers, low-loss, low differential mode delay multi-mode fiber, and a coherent 110x110 MIMO digital signal processor.
2022 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)
(2022)
Proceedings Paper
Computer Science, Hardware & Architecture
Luis Felipe Florenzan Reyes, Francesco Smarral, Roland Ryf, Tetsuya Hayashi, Andrea Marotta, Cristian Antonelli, Alessandro D'Innocenzo
Summary: This paper discusses the use of data-driven methodologies to improve the performance of crosstalk cancelation in optical systems supporting multiple spatial modes. It proposes a reduction algorithm based on PCA and cross-correlation analysis to enhance the traditional equalizers' performance. Experimental validation is conducted over the world-first SDM field trial.
2022 31ST INTERNATIONAL CONFERENCE ON COMPUTER COMMUNICATIONS AND NETWORKS (ICCCN 2022)
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Tetsuya Hayashi, Takuji Nagashima, Ayumi Inoue, Hirotaka Sakuma, Takahiro Suganuma, Takemi Hasegawa
Summary: This article reviews and discusses the design factors and considerations of MCFs for bidirectional transmissions, including connection polarity and crosstalk requirements, and introduces MCFs suitable for bidirectional long-haul and short-reach transmissions.
2022 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Mikael Mazur, Lauren Dallachiesa, Nicolas K. Fontaine, Roland Ryf, Erik Borjeson, Haoshuo Chen, Hirotaka Sakuma, Takafumi Ohtsuka, Tetsuya Hayashi, Takemi Hasegawa, Hidehisa Tazawa, David T. Neilson, Per Larsson-Edefors
Summary: We have conducted the first transmission experiment using a 7-core coupled-core fiber and in-line coupled-core multi-core amplifiers, and implemented real-time DSP with a single FPGA for MIMO processing across all 7 cores.
2022 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Mikael Mazur, Nicolas K. Fontaine, Steve Corteselli, Haoshuo Chen, Lauren Dallachiesa, Tetsuya Hayashi, Hirotaka Sakuma, Takemi Hasegawa, Roland Ryf, David T. Neilson
Summary: In this study, dual-comb spectroscopy was used to compare the stability and wavelength dependence of mode coupling in a 110 km coupled multi-core fiber and a regular single-mode fiber, revealing differences in coupling dynamics.
2022 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)
(2022)
Proceedings Paper
Computer Science, Information Systems
Ekaterina Deriushkina, Israel Rebolledo Salgado, Mikael Mazur, Victor Torres-Company, Peter Andrekson, Simon Gross, Michael J. Withford, Tetsuya Hayashi, Takuji Nagashima, Jochen Schroder, Magnus Karlsson
Summary: In this study, a novel method combining swept-wavelength interferometry and dual-comb spectroscopy was employed to measure the transfer matrix of a coupled three-core fiber. The technique achieved a high frequency resolution of 50 kHz while measuring a bandwidth of 1 THz, with just a 25 GHz laser sweep.
2021 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)
(2021)
