Sumitomo Electric Industries, Ltd. is pleased to announce the publication of its Integrated Report 2024.

Sumitomo Electric Industries, Ltd. will demonstrate a point-to-multipoint connection service over a reconfigurable optical add/drop multiplexer (ROADM) network, using ICE-X coherent communication^*1 for the first time in Japan at   Interop Tokyo 2024. The event will be held from June 12 to 14 at Makuhari Messe in Chiba.  

Interop Tokyo is one of the largest information and communication technology (ICT) exhibitions in Japan, where exhibitors build an Internet connection environment called ShowNet using their latest technologies and cutting-edge equipment with innovative features and conduct a variety of interoperability verification demonstrations.

Sumitomo Electric has been collaborating with Infinera to utilize features of the ICE-X coherent transceiver. Sumitomo Electric will offer point-to-multipoint connection service over a ROADM network at the ShowNet with our metro/aggregation Ethernet switch “FTU9100” currently under development to take advantage of Infinera’s optical coherent transceiver^*2 “ICE-X coherent transceiver.” The collaboration has led to the accomplishment of point-to-multipoint connection service with live traffic to the Internet over a ROADM network using ICE-X coherent communication for the first time in Japan.

General optical transceivers connect a location to another location over optical fibers, while ICE-X coherent transceivers have a capability of connecting a location to multiple locations over a passive optical network.
This feature enables point-to-multipoint connection service without using electrical switches or routers between locations and a reduced number of optical fibers required in the field to result in a reduction of Total Cost of Ownership.

This achievement serves as a key technology advancement for expanding the coverage area of All-Photonics Network^*3 (APN) at low cost and meet societal demands such as high speed, high capacity, low delay, and energy efficiency.

Sumitomo Electric expects that the combination of ICE-X coherent technology and Sumitomo Electric’s expertise and experience in access networks will make innovative new products to enable extra-high-speed communication services. New services such as 5G mobile xHaul and low-cost edge computing will also be supported.

KDDI Corporation (headquartered in Chiyoda-ku, Tokyo; President and CEO: Makoto Takahashi, hereinafter, “KDDI”), KDDI Research, Inc. (headquartered in Fujimino-shi, Saitama; President: Hajime Nakamura, hereinafter, “KDDI Research”), Sumitomo Electric Industries, Ltd. (headquartered in Osaka City, Osaka; President: Osamu Inoue, hereinafter “Sumitomo Electric”), Furukawa Electric Co., Ltd. (headquartered in Chiyoda-ku, Tokyo; President: Hideya Moridaira, hereinafter “Furukawa Electric”), and OFS Laboratories, LLC (headquartered in United States; hereinafter “OFS”) have conducted successful experiments on ultrawideband optical fiber transmission with a transmission bandwidth of 115.2 THz (approximately 24 times wider than conventional C-band), the world’s largest (transmission capacity: 484 Tbps, transmission distance: 31 km) ^{(Note 1)} in optical fiber transmission experiments using standard optical fiber diameter. This was done by combining uncoupled 12-core optical fiber that has 12 independent cores densely arranged in a 250-μm coating ^{(Note 2)}, the same size as a standard optical fiber, and a broadband O-band optical fiber amplifier (BDFA).

In the 6G era, it is expected that far more and diverse data will flow through networks than at present due to the spread of IoT (Internet of Things) devices and mobility services, and it is essential to further expand the capacity of optical fiber communication to support networks. The success this time is in technology for supporting high-capacity, high-speed communication between data centers in the 6G era. Furthermore, the same transmission capacity can be secured with fewer fiber cores since the transmission capacity per optical fiber can be greatly expanded, and this technology is expected to enable the use of ordinary conduits and facilities with less space occupied.

These results were reported as a post-deadline paper ^{(Note 3)} at ECOC 2023 (European Conference on Optical Communications), one of the largest international academic conferences on optical communications technology, held from October 1 to 5, 2023.

Background
The capacity of optical fiber communication needs to be further expanded to support networks in the 6G era.
Transmission capacity per optical fiber can generally be increased by using wavelength division multiplexing, in which the wavelength of light is slightly changed for multiplexed transmission.

Until now, KDDI Research, Sumitomo Electric, and Furukawa Electric have been working toward practical application of multi-core optical fibers, which have multiple cores in a single optical fiber ^{(Note 4)}. In March 2023, KDDI Research, Furukawa Electric, and OFS conducted successful O-band coherent dense wavelength division multiplexing (DWDM) transmission ^{(Note 5)} experiments to utilize the O-band, which has approximately twice the transmission bandwidth of the C- and L-bands _{^{(Note 6)}}. Furthermore, in March 2023, Sumitomo Electric presented a high-density uncoupled 12-core optical fiber with a coating diameter of 250 μm, the same diameter of standard optical fibers, making it ideal for creating high-density optical cables ^{(Note 7)}.

Results this time
KDDI, KDDI Research, Sumitomo Electric, Furukawa Electric, and OFS have succeeded in experiments in high-capacity transmission with a transmission bandwidth of 115.2 THz by using the high-density uncoupled 12-core optical fiber with a coating diameter of 250 μm and combining it with O-band coherent DWDM transmission technology, which significantly reduces the effects of inter-core crosstalk.

Please refer to the appendix for details.

The O-band has an advantage in that it can reduce the signal processing load to compensate for wavelength dispersion ^{(Note 8)} because the effect of wavelength dispersion is smaller than that of the C-band, but it has a drawback that the quality of the optical signal is easily degraded due to nonlinear optical effects ^{(Note 9)}. Therefore, the O-band has been considered unsuitable for increasing the capacity of optical fiber communication systems. KDDI Research has developed O-band coherent DWDM transmission technology that enables high-capacity transmission by suppressing nonlinear optical effects through optimization of the transmission power of optical signals.

Wavelength division multiplexing of more optical signals is effective in increasing the capacity of optical fiber communication, but this requires optical fiber amplifiers that can amplify a broader wavelength band. The BDFA developed by Furukawa Electric and OFS can amplify optical signals over the entire O-band, which is broader than the C-band and L-band combined. This experiment showed that an ultrawideband comparable to the C+L band can be achieved by amplifying coherent DWDM signals over 9.6 THz in the O-band.

Furthermore, by applying multi-core optical fiber, in which multiple cores that are paths for optical signals are arranged in a single optical fiber, the transmission capacity per optical fiber can be expanded by the number of cores. Sumitomo Electric has focused on the fact that optical signals in the O-band are more strongly confined by the core than in the C-band, and it has developed an uncoupled 12-core optical fiber with 12 independent cores densely clustered within the standard optical fiber outer diameter of 250 μm.

It was demonstrated that, by combining these three technologies, the total available bandwidth per optical fiber can be extended to 115.2 THz, and a 484 Tbps high-capacity transmission experiment was successfully conducted as one example. This is the world’s largest bandwidth and transmission capacity in a demonstration experiment for a single wavelength band, not a combination of multiple wavelength bands.

Future outlook
In the future, research and development will continue for transceivers, optical fiber amplifiers, and digital signal processing algorithms toward the practical application of ultrawideband O-band coherent DWDM transmission systems, with an aim of further increasing transmission capacity between data centers.

Notes
Part of this research and development is the result of Project JPNP20017 commissioned by the New Energy and Industrial Technology Development Organization (NEDO), a national research and development agency.

(Note 1) Surveyed by KDDI Research on October 20, 2023
(Note 2) Multi-core optical fiber with standard coating diameter that can use existing optical cables.
(Note 3) Post-deadline paper: A paper accepted after the general paper submission deadline (post-deadline). Paper selection is conducted during
the conference period, and only highly rated research results are given the opportunity to be reported.
(Note 4) Press release on March 28, 2022
Development and Demonstration of World-leading Technologies that Increase Submarine Optical Cable Capacity with Multicore Fiber.
https://www.kddi-research.jp/english/newsrelease/2022/032801.html
(Note 5) Coherent dense wavelength division multiplexing (DWDM) transmission: Coherent transmission is a method of transmitting a larger volume of data than conventional intensity modulation-direct detection technology by using the properties of light as waves as well as the light intensity. Dense wavelength division multiplexing (DWDM) is a method of densely multiplexing wavelengths in WDM (Wavelength Division Multiplexing) technology, which increases the transmission density of optical fibers.
(Note 6) Press release on May 18, 2023
Utilization of ultrawide bands to increase the capacity of optical fiber communication: The world’s first successful O-band coherent high-density wavelength division multiplexing transmission experiment
https://www.kddi-research.jp/english/newsrelease/2023/051801.html
(Note 7) T. Hayashi, A. Inoue, Y. Suzuki, Y. Norisugi, K. Kawamoto, J. Takano, T. Nagashima, T. Hirama, K. Takeda, Y. Shimoda, and F. Sato, “Ultra-High-Density Microduct Cable with Uncoupled 12-Core Fibers with Standard 250-µm Coating,” in Optical Fiber Communication Conference (OFC) 2023, Technical Digest Series (Optica Publishing Group, 2023), paper Tu2C.2.
https://doi.org/10.1364/OFC.2023.Tu2C.2
(Note 8) Wavelength dispersion: A phenomenon in which light propagates at different speeds at different wavelengths. Since optical signals contain slightly different wavelength components, the longer the propagation distance, the more the optical signal distorts due to wavelength dispersion.
(Note 9) Nonlinear optical effect: A phenomenon in which an optical signal interferes with a component of its own optical signal or a component of another optical signal multiplexed to a different wavelength, causing distortion of the optical signal.

Inquiries
KDDI Research, Inc. Public Relations Group
https://www.kddi-research.jp/english/inquiry.html

Sumitomo Electric Industries, Ltd.,
https://sumitomoelectric.com/contact-us

Furukawa Electric Co., Ltd. Public Relations Department
https://inquiry-fec-form.spiral-site.com/ennews?id=ennews&_ifbs-ennews=s1_input

Sumitomo Electric Industries, Ltd. will exhibit at GITEX GLOBAL 2023, one of the largest information technology exhibitions in the Middle East region, to be held in Dubai, United Arab Emirates from October 16 to 20, 2023.

Sumitomo Electric’s high-definition core aligning fusion splicer TYPE-72C+ is equipped with its patented artificial intelligence technology NanoTune, which enables fine tuning and fusion splicing regardless of the operating environment or skill level. It also has excellent features such as high splicing quality and high-speed fiber reinforcement. Other products featured at the exhibition will include the PureAdvance series, ultra-low attenuation and large core optical fibers, which are designed for long-distance and high-capacity optical signal transmission. In addition, the Company’s new ribbon fusion splicer TYPE-72M12+ and other telecommunication-related products will be on display. Assembly demonstrations of the field installable connector Lynx-CustomFit Splice-On Connector will also be conducted.

GITEX2023 is a large-scale exhibition that showcases cutting-edge IT-related products and technologies for next-generation trends such as telecommunications, cybersecurity, data economy, digital city x AI, future mobility, and healthcare.

Please visit the Sumitomo Electric booth.

「GITEX GLOBAL 2023」 Exhibition Outline

Date	Monday, October 16 – Friday, October 20, 2023
Venue	Dubai World Trade Centre, United Arab Emirates
Booth No.	H20-08
Official website	https://www.gitex.com/
Exhibits	・Fusion splicers: TYPE-72M12＋, TYPE-72C+, T-57C+, etc. ・Optical closures: GP8 series ・Optical connectors: Lynx-CustomFit series ・Optical cables: High count cable, micro cable series ・Optical fibers: PureAdvance series ・Multi-core fiber

〈References〉
・Sumitomo Electric Fusion splicers
Website
https://global-sei.com/sumitomo-electric-splicers/
LinkedIn*¹
https://www.linkedin.com/showcase/sumitomoelectricfusionsplicer/
Facebook*²
https://www.facebook.com/sumitomoelectricsplicer/

・Sumitomo Electric Optical fiber-related products
Website
https://global-sei.com/fttx/
LinkedIn*¹
https://www.linkedin.com/showcase/sumitomo-electric-fiber-optics-products/

*1 LinkedIn is a trademark or registered trademark of LinkedIn Corporation and/or its affiliates in the U.S. and other countries.
*2 Facebook is a trademark or registered trademark of Meta Platforms, Inc. in the U.S. and other countries.

Sumitomo Electric Industries, Ltd. has improved the transmission loss of terrestrial optical fiber cables using PureAdvance^TM-110, a pure-silica-core, low-loss, large effective-area (A_eff) fiber. These cables have been selected for a data center interconnect (DCI) project, and the delivery has recently been completed.

With increasing data traffic in trunk networks and between data centers, there is growing demand for broadband optical transport networks, and accordingly, optical fiber cables with improved performances, such as lower transmission loss, are increasingly required.

Since 2017, Sumitomo Electric has been commercially supplying the low-loss, large A_eff pure-silica-core fiber PureAdvance^TM-110 and optical fiber cables using it for terrestrial trunk transmission lines.^*1 These fiber cables are compliant with Recommendation ITU-T G.654.E^*2 and suitable for long-haul high-capacity optical signal transmissions thanks to their superior performances of low transmission loss and large A_eff.
To achieve even lower transmission loss, Sumitomo Electric applied ultra-low-loss pure-silica-core fiber technologies.^*3 As a result, the transmission loss of optical fiber cables using PureAdvance^TM-110 has been improved from 0.17 dB/km to 0.16 dB/km or below (typical value at a wavelength of 1550 nm), making it the world’s lowest transmission loss for terrestrial cables.^*4

The terrestrial optical fiber cables using PureAdvance^TM-110 have been selected for a wide-area DCI project connecting data center clusters in Tokyo, Kanagawa, and Chiba (Fig. 1), and the delivery has been completed. The outstanding low-loss performance of these cables enables to construct extremely low-loss transmission links including a 157 km-long section with the total loss of as low as 36 dB after deployment (including splice and connector losses). This will allow for high-capacity data transmission between data centers and reduce the number of optical repeaters, realizing reliable transmission links with reduced overall system costs.

Sumitomo Electric will continue to develop and supply low-loss optical fiber cables, contributing to the realization of high-quality optical communication networks.