Article
Engineering, Electrical & Electronic
Tiago M. F. Alves, Adolfo V. T. Cartaxo, Joao L. Rebola
Summary: This study investigates numerically and experimentally the effects of intercore crosstalk (ICXT) and laser phase noise on direct-detection on-off keying (DD-OOK) weakly-coupled multicore fiber (WC-MCF) systems. It is found that laser phase noise increases the power fluctuations of ICXT, and the standard deviation of the power depends on the product of laser linewidth and core skew.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Tristan Kremp, Yue Liang, Alan H. McCurdy
Summary: Multicore fiber is a promising technology to increase the transmission bandwidth of optical fiber links. Fusion splicing is indispensable for connecting multicore fibers, and precise alignment is crucial to minimize insertion loss. This paper presents an azimuthal alignment algorithm based on side-view images, which considers the twist rates of the fibers. The algorithm has been demonstrated to be stable and versatile for various fibers, achieving low splice losses and accurate twist rate detection.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Computer Science, Hardware & Architecture
Yuya Seki, Yosuke Tanigawa, Yusuke Hirota, Hideki Tode
Summary: Space-division multiplexing elastic optical networks (SDM-EONs) with multi-core fibers (MCFs) have been improved by solving the route, modulation format, core, and spectrum assignment problems, but inter-core crosstalk (IC-XT) still needs to be addressed. This paper proposes a hierarchical core prioritization method to mitigate IC-XT and demonstrates its effectiveness through simulation results.
JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING
(2023)
Article
Engineering, Electrical & Electronic
Tiago M. F. Alves, Adolfo V. T. Cartaxo
Summary: The impact of polarization misalignment between signal and intercore crosstalk (ICXT) on the performance of direct detection weakly coupled multicore fiber systems is investigated. It is found that aligning the signal field polarization with the polarized component of ICXT does not maximize the bit-error ratio (BER) at all times, but leads to more frequent occurrence of higher levels of BER. Compared with independent polarizations of signal and ICXT fields, this scenario requires an incremental requirement of ICXT level between 1 dB and 2 dB for the same outage probability. These findings apply to on-off-keying direct detection weakly coupled multicore fiber short-reach systems operating with arbitrary skew and bit rate.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Joao L. Rebola, Tiago M. F. Alves, Adolfo V. T. Cartaxo
Summary: The outage probability due to intercore crosstalk in short-reach binary intensity modulation-direct detection optical links supported by homogeneous weakly-coupled multicore fibers is evaluated through numerical simulation. It is found that the acceptable ICXT level per core decreases by 3 dB when the number of interfering cores doubles for high skew-bit rate products, but only by about 2 dB for low skew-bit rate products. Additionally, the total acceptable ICXT level increases with the interfering core count, particularly for low skew-bit rate products.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2021)
Article
Optics
Afzal Hossain, S. P. Majumder
Summary: The study found that crosstalk in 9-core and 7-core multi-core optical fibers is more pronounced compared to the 3-core fiber, leading to significant deterioration in Bit Error Rate (BER) performance. Additionally, there is a minimum achievable BER corresponding to specific core pitch and number.
Article
Engineering, Electrical & Electronic
Hirotaka Ono, Makoto Yamada
Summary: The analysis focuses on the power consumption of optical repeater subsystems in a multicore fiber link, comparing the power consumption of subsystems using multicore EDFAs with those using multiple single-core EDFAs. The results indicate that multicore EDFAs have certain advantages over single-core EDFAs in terms of power consumption efficiency.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Hitoshi Takeshita, Yusuke Shimomura, Kohei Hosokawa
Summary: This work investigates the feasibility of improving the energy efficiency of a cladding-pumped multicore (MC) EDFA by utilizing bidirectional (BD) pumping. It demonstrates that the optical power loss due to equalization can be reduced by controlling the optical power ratio of the forward and backward pumps. Under optimized conditions, a 1.7% pump conversion efficiency improvement and a 24% reduction in total optical pump power compared to conventional MC-EDFA were achieved.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Optics
Yu Yang, Ruiting Cheng, Jiaxin Liu, Mingqing Zuo, Yuyang Gao, Lei Shen, Lei Wang, Xiaoyu Zhu, Zhangyuan Chen, Yongqi He, Juhao Li
Summary: This paper evaluates the influence of Fan-in/fan-out (FI/FO) devices on short-reach optical interconnect and successfully demonstrates high-speed optical interconnection using low-crosstalk compact devices fabricated by the laser-direct-writing (LDW) technique.
Article
Engineering, Electrical & Electronic
Charles Matte-Breton, Rene-Jean Essiambre, Colin Kelly, Younes Messaddeq, Sophie LaRochelle
Summary: We report the characterization of a cladding-pumped multicore fiber with annular erbium doping for low gain compression over the C-band. The experimental results show that significant reduction in gain compression of multicore cladding-pump amplifiers can be achieved with the proposed annular doping design in the cladding.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Wenjie Wang, Lian Xiang, Weidong Shao, Gangxiang Shen
Summary: A novel universal semi-analytical model (USAM) for intercore crosstalk (ICXT) in weakly coupled multicore fibers (MCFs) is derived based on coupled mode theory (CMT). The model provides accurate and fast simulation results for real weakly coupled MCFs and has a wider scope of application compared to other CMT-based models.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Xutao Wang, Honglin Sun, Huihui Wang, Zhiqun Yang, Yaping Liu, Zhanhua Huang, Lin Zhang
Summary: In the context of Industry 4.0, the smart oilfield introduces the use of multicore fibers for increased data transmission capacity and high-sensitivity distributed sensing. This paper proposes a heterogeneously integrated seven-core fiber for interconnection and awareness applications in smart oilfields, which supports digital and analog signal transmission as well as temperature and vibration measurement. The proposed fiber exhibits great potential for efficient and cost-effective oil production in smart oilfields.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Electrical & Electronic
Junjiang Xiang, Meng Xiang, Hong Lv, Gai Zhou, Hailin Yang, Xinkuo Yu, Jianping Li, Yuwen Qin, Songnian Fu
Summary: In this study, a data-driven nonlinear equalizer based on a conditional generative adversarial network (c-GAN) is proposed for improving the throughput of photonic data-center interconnection. Experimental results demonstrate that the proposed equalizer outperforms traditional methods and other data-driven approaches in terms of both bit-error ratio (BER) and computational complexity. The proposed equalizer can guarantee the BER performance of all 40 channels and significantly reduce the computational complexity.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Qi Chen, Bowen Chen, Wenwen Zheng, Yunfei Jiang, Jinbing Wu, Hong Chen, Mingyi Gao, Weidong Shao, Pin-Han Ho
Summary: This paper addresses the mapping problems of virtual optical networks onto space-division-multiplexing elastic optical data center networks. It proposes the concepts of link importance degree and node importance degree and develops VON mapping approaches based on optimization formulas. Simulation results show that the proposed approach achieves solutions closest to the optimal ones and improves network profit effectively.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Computer Science, Hardware & Architecture
Bijoy Chand Chatterjee, Abdul Wadud, Imran Ahmed, Eiji Oki
Summary: The paper introduces a priority-based crosstalk-avoided core, mode, and spectrum allocation scheme in SS-EONs, which enhances resource utilization, reduces blocking probability, and allows higher traffic loads.
IEEE-ACM TRANSACTIONS ON NETWORKING
(2021)
Article
Engineering, Electrical & Electronic
Bruno R. P. Pinheiro, Joao L. Rebola, Adolfo V. T. Cartaxo
Summary: The influence of inter-core crosstalk (ICXT) on the performance of weakly-coupled multi-core fiber systems with coherent detection was studied. The study showed that with increasing skew-symbol rate product, system stability and maximum allowable ICXT level also increased, aligning with the results of other experiments.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Optics
Rafael Dias, Joao Rebola, Adolfo Cartaxo
Summary: In this study, the use of PAM4 and multi-core fibers for high capacity datacenter interconnect links was proposed, with a focus on the impact of ICXT on link performance. It was found that varying ICXT levels are needed in different scenarios to ensure the stability of the links.
Article
Engineering, Electrical & Electronic
Joao L. Rebola, Tiago M. F. Alves, Adolfo V. T. Cartaxo
Summary: The outage probability due to intercore crosstalk in short-reach binary intensity modulation-direct detection optical links supported by homogeneous weakly-coupled multicore fibers is evaluated through numerical simulation. It is found that the acceptable ICXT level per core decreases by 3 dB when the number of interfering cores doubles for high skew-bit rate products, but only by about 2 dB for low skew-bit rate products. Additionally, the total acceptable ICXT level increases with the interfering core count, particularly for low skew-bit rate products.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Diogo Sequeira, Luis Cancela, Joao Rebola
Summary: This study evaluated the impact of various physical layer impairments on optical networks based on reconfigurable optical add/drop multiplexers, showing that specific add/drop structures in different scenarios can achieve the best cost/performance ratio in different types of networks under different signal conditions.
OPTICAL FIBER TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Adolfo V. T. Cartaxo, Jose A. P. Morgado
Summary: A closed-form expression is proposed for evaluating mean inter-core crosstalk (ICXT) power in weakly-coupled multi-core fibers, showing improved accuracy compared to the existing expression by Koshiba. The proposed expression predicts a significant influence of the twisting period on the mean ICXT power, in qualitative agreement with experimental results reported by other authors.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Tiago M. F. Alves, Adolfo V. T. Cartaxo, Joao L. Rebola
Summary: This study investigates numerically and experimentally the effects of intercore crosstalk (ICXT) and laser phase noise on direct-detection on-off keying (DD-OOK) weakly-coupled multicore fiber (WC-MCF) systems. It is found that laser phase noise increases the power fluctuations of ICXT, and the standard deviation of the power depends on the product of laser linewidth and core skew.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
Derick Piedade, Tiago Alves, Tomas Brandao
Summary: This paper proposes and evaluates the use of machine learning techniques for mitigating the effect of random inter-core crosstalk on short-reach systems. The performance improvement provided by different techniques is assessed and compared, with the feedforward neural network proving to significantly improve system performance.
Proceedings Paper
Engineering, Electrical & Electronic
T. M. F. Alves, J. L. Rebola, A. V. T. Cartaxo
Summary: The experimental investigation of on-off-keying multicore fiber systems employing different lasers found that laser phase noise increases the instantaneous fluctuations of the crosstalk. DFB-based systems may require an additional crosstalk margin of 4 dB relative to ECL-based systems.
2021 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXPOSITION (OFC)
(2021)
Proceedings Paper
Optics
Rafael A. Dias, Joao L. Rebola, Adolfo V. T. Cartaxo
Summary: This study proposes using PAM4 and MCFs for high capacity inter-datacenter connections, analyzing the impact of ICXT on the performance of 112 Gb/s optically amplified PAM4 inter-datacenter links through numerical simulation.
PHOTOPTICS: PROCEEDINGS OF THE 9TH INTERNATIONAL CONFERENCE ON PHOTONICS, OPTICS AND LASER TECHNOLOGY
(2021)
Proceedings Paper
Optics
Tiago D. Freitas M, Tiago M. F. Alves, Adolfo V. T. Cartaxo
Summary: A new transmission scheme for DD short-reach networks based on multicore-fibre is proposed, with a low complexity SSBI mitigation approach. Numerical simulation evaluates the performance of a 200 Gb/s binary NRZ signal, showing potential applications in intra DC networks under specific conditions.
PHOTOPTICS: PROCEEDINGS OF THE 9TH INTERNATIONAL CONFERENCE ON PHOTONICS, OPTICS AND LASER TECHNOLOGY
(2021)