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
Yiyang Shu, Xun Luo
Summary: This article proposes a scalable inter-core-shaping multi-core oscillator that achieves low phase noise and high FoM at millimeter-wave band. The oscillator utilizes differential capacitors and common-mode resonance to reduce phase noise effectively. It also demonstrates low sensitivity to parasitics and core mismatch in its design.
IEEE JOURNAL OF SOLID-STATE CIRCUITS
(2023)
Article
Thermodynamics
Nicholas Kempf, Mortaza Saeidi-Javash, Haowei Xu, Sheng Cheng, Megha Dubey, Yaqiao Wu, Joshua Daw, Ju Li, Yanliang Zhang
Summary: This study demonstrates the successful use of nanostructured bulk materials in a thermoelectric generator (TEG) to generate stable and high electrical power density in the harsh radiation environment of a nuclear reactor core. By controlling the operating temperature, the thermoelectric properties of the material can be recovered, allowing for continuous operation.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Chemistry, Multidisciplinary
Jialin Ji, Qinghang Tang, Mingjia Yao, Hongliang Yang, Yeqing Jin, Yubo Zhang, Jinyang Xi, David J. Singh, Jiong Yang, Wenqing Zhang
Summary: This study demonstrates the use of functional-unit-based material design for thermoelectrics. By screening compounds with linear triatomic resonant bonds (LTRBs), it is found that these compounds exhibit strong anisotropy both structurally and electronically, as well as strong anharmonic phonon scattering. Compounds containing LTRBs have lower lattice thermal conductivities and remarkable band anisotropy near the valence band maximums. The correlation between LTRB and thermoelectric properties is elucidated through a case study on K5CuSb2.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Analytical
Chengrui Zhang, Yi Zhou, Lan Mi, Jiong Ma, Xiang Wu, Yiyan Fei
Summary: Guided-mode resonance (GMR) sensors are widely used in biosensing due to their simple structure, easy detection schemes, high efficiency, and narrow linewidth. However, their applications are limited by their relatively low sensitivity and figure of merit. By introducing a metal layer-assisted double-grating (MADG) structure, both sensitivity and figure of merit can be enhanced simultaneously for more sensitive sensing.
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
Xiaofan Ji, Yaping Liu, Honglin Sun, Wenbo Yu, Zhiqun Yang, Lin Zhang
Summary: In this paper, we study the scaling of nonlinear impairment in coupled-core multi-core fibers (CC-MCFs) with different core counts. The results show that increasing the number of cores in CC-MCFs significantly weakens the nonlinear signal degradation, which is of great interest for ultralong-haul transmission. We further analyze the impact of fiber loss, differential group delay, and effective mode field area on this trend. Moreover, we compare CC-MCFs with few-mode fibers with the same number of spatial modes and find that CC-MCFs tend to have better nonlinear performance. It is also shown that few-mode fibers operated in a strong coupling regime are promising for long-haul transmission.
OPTICS COMMUNICATIONS
(2023)
Article
Optics
Egor Manuylovich, Aleksandr Donodin, Sergei Turitsyn
Summary: This paper presents a new mode decomposition technique that outperforms the fastest previously published method in terms of the number of modes while maintaining the same speed of decomposition. The technique improves signal-to-noise ratio by 10 dB for a 3-mode fiber and by 7.5 dB for a 5-mode fiber, demonstrating its effectiveness in optical field recovery and mode decomposition in multi-mode fibers.
Article
Optics
Zhixiang Yang, Yifei Zhao, Yifan Zhang, Guiyao Zhou
Summary: This paper presents a novel 7-core 5-mode fiber that has a large mode area and low inter-core crosstalk. By utilizing an air-trench structure and high-index ring, the proposed fiber achieves large mode area and low crosstalk. Numerical analyses demonstrate that the fiber can reliably transmit 5 LP modes in the C+L band, with an effective mode area of each LP mode larger than 110 square micrometers and a crosstalk smaller than -79 dB/km. Each mode has an effective refractive index difference larger than 1.1 x 10-3. Therefore, even when the mode area is large, a low crosstalk can still be achieved. The proposed fiber can be used to construct a high-capacity fiber optic transmission system.
Article
Engineering, Electrical & Electronic
Shan Wang, Yuwen Qin, Ou Xu, Jianping Li, Songnian Fu
Summary: The study shows that the polarization-maintaining multi-core few-mode fiber can provide 19 parallel channels with low inter-core crosstalk, and its cladding diameter is the same as that of standard single-mode fiber, making it convenient for upgrading.
IEEE PHOTONICS JOURNAL
(2021)
Article
Optics
Pavel S. Anisimov, Evgeny D. Tsyplakov, Viacheslav V. Zemlyakov, Jiexing Gao
Summary: We present an alternative method for compensating intermodal interactions in few-mode optical fibers using digital backpropagation. Instead of solving the inverse generalized multimode nonlinear Schrodinger equation, we utilize a deep neural network to backpropagate multimode signals based on their near-field intensity distributions captured by a camera. We demonstrate the feasibility of this approach by training an autoencoder for backpropagation of six linearly polarized modes in a step-index fiber.
CHINESE OPTICS LETTERS
(2023)
Article
Multidisciplinary Sciences
Dongwang Yang, Xianli Su, Jian He, Yonggao Yan, Jun Li, Hui Bai, Tingting Luo, Yamei Liu, Hao Luo, Yimeng Yu, Jinsong Wu, Qingjie Zhang, Ctirad Uher, Xinfeng Tang
Summary: Researchers have successfully synthesized beta-Zn4Sb3 with improved stability and extended temperature range using an electric field-assisted method, and found that the mobile ions play a crucial role in enhancing the thermoelectric performance of the material.
NATURE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Prabal Dev Bhuyan, P. N. Gajjar, Rita Magri, Sanjeev K. Gupta
Summary: By introducing vacancies and doping with different transition metals, the thermoelectric performance of Sb/Ge core/shell nanowires can be improved, enhancing energy conversion efficiency.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Electrical & Electronic
Xin Huang, Yongmin Jung, Yaping Liu, Kerrianne Harrington, David J. Richardson
Summary: A simple, low loss, and broadband mode scrambler for mode division multiplexed transmission based on few-mode fibers is presented. The optical bandwidth is significantly enhanced by shortening the length of the long-period fiber grating (LPFG), and a wideband operation with low loss (0.2 dB) and low mode dependent loss (0.1 dB) is achieved using a mechanically induced LPFG fabricated with a commercially available 3D printing technique.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Yiyang Shu, Huizhen Jenny Qian, Xiang Gao, Xun Luo
Summary: A distributed-swing-boosting and harmonic-impedance-expanding multi-core oscillator is proposed to achieve low phase noise and high figure-of-merit. The structure utilizes CM and DM resonances to suppress flicker noise and achieve harmonic shaping. Fabricated in a 40-nm CMOS process, the oscillator exhibits low phase noise and high FoM simultaneously.
IEEE JOURNAL OF SOLID-STATE CIRCUITS
(2021)
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
Davide Bacco, Nicola Biagi, Ilaria Vagniluca, Tetsuya Hayashi, Antonio Mecozzi, Cristian Antonelli, Leif K. Oxenlowe, Alessandro Zavatta
Summary: Multicore fibers are expected to revolutionize optical communications with their larger transmission bandwidth and smaller footprint. Although recent research has explored their use in quantum communication, the feasibility of using long-distance multicore fibers for quantum applications still needs to be proven.
PHOTONICS RESEARCH
(2021)
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)
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
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)
Proceedings Paper
Computer Science, Information Systems
Mikael Mazur, Nicolas K. Fontaine, Roland Ryf, Haoshuo Chen, Lauren Dallachiesa, Takafumi Ohtsuka, Hirotaka Sakuma, Tetsuya Hayashi, Takemi Hasegawa, Hidehisa Tazawa, David T. Neilson
Summary: This study presents the full transfer matrix characterization of a packaged 7-core coupled-core amplifier, achieving a small mode-dependent loss through pump current optimization. The observed loss is about 3 dB over a gain range of 17 to 25 dB.
2021 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Ruben S. Luis, Benjamin J. Puttnam, Georg Rademacher, Andrea Marotta, Cristian Antonelli, Fabio Graziosi, Antonio Mecozzi, Tetsuya Hayashi, Tetsuya Nakanishi, Satoshi Shinada, Yoshinari Awaji, Hideaki Furukawa, Naoya Wada
Summary: This study reviews recent works analyzing inter-core skew in multi-core fibers, comparing the behaviors of spooled fibers in laboratory conditions with field deployed fibers.
2021 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXPOSITION (OFC)
(2021)
