September 2016 Vol. 14 No. 9

Feature Articles: Device Technology Development for Beyond 100G Optical Transport Network

• Device Technology Development for Beyond 100G Optical Transport Network

  

  Abstract
  The capacity of the optical transport network has been expanding for over 30 years, which has enriched the communication environment of users. This expansion has also helped to reduce the cost of communication lines and facilitate the growth of the Internet and the widespread use of smartphones. In the near future, an optical transport network with a capacity beyond 100 Gbit/s per wavelength (beyond 100G optical transport network) and its device technology will be needed in order to provide more sophisticated communication services such as IoT (Internet of Things) and 5G (fifth-generation) mobile access. This article reviews NTT laboratories’ development of device technology for the beyond 100G optical transport network.

• Digital Signal Processor (DSP) for Beyond 100G Optical Transport

  

  Abstract
  As a foundation for the coming full-fledged big data society, optical communication networks must further advance in speed, capacity, and cost-effectiveness. This article introduces beyond 100G (beyond 100 Gbit/s per channel) digital coherent optical transmission technology, which is a key to developing high-capacity optical communication networks, and the digital signal processor (DSP) that provides core functions for this technology.

• Compact Optical Modulator and Coherent Optical Subassemblies for Beyond 100G Transport Network

  

  Abstract
  This article presents an indium-phosphide-based optical modulator and a silicon-photonics-based coherent optical subassembly. Both devices enable compact and low-power beyond 100G (beyond 100 Gbit/s per wavelength) digital coherent transceivers that are essential for constructing an optical transport network economically.

• High-sensitivity 4-channel Receiver Module with Avalanche Photodiode for 400-Gbit/s Ethernet

  

  Abstract
  We developed an integrated 4-channel receiver optical subassembly (ROSA) with high-sensitivity avalanche photodiode (APD) for 400-Gbit/s Ethernet. A minimum receiver sensitivity of −21.2 dBm with a 4-channel × 28-Gbaud PAM-4 (four-level pulse amplitude modulation) APD-ROSA was achieved, enabling us to achieve 30-km transmission.

• High Frequency Optical Module Assembly Technique Enabling High Modulation Speed over 100 Gbit/s/λ

  

  Abstract
  A novel optical module assembly technique enabling high modulation bandwidth is described. This optical module features not only high modulation bandwidth but also a small footprint and low-power dissipation. These features help accelerate optical module development for 400-Gigabit Ethernet applications.

Global Standardization Activities

• Promotion of Environmental Management According to ITU-T L.1410 in NTT Group

  

  Abstract
  The NTT Group is moving forward with environmental management practices conforming to ITU-T (International Telecommunication Union - Telecommunication Standardization Sector) Recommendation L.1410. Here, we describe the promotion of energy-saving technology for datacenters, the evaluation of environmental contributions of products and services developed by NTT laboratories, and the environmental solution label.

Global Activities of NTT Group

• Arkadin: Global Unified Communications & Collaboration Champion in a Dynamic Digital Workplace

  

  Abstract
  Arkadin is one of the largest and fastest growing communications and collaboration service providers in the world. With a vision rooted in the belief that progress emerges from people’s desire to share, Arkadin offers a complete range of integrated audio, web, video, and unified communications solutions. This article introduces the company’s operations, strategies, and potential future as an NTT Communications Group company.

New NTT Colleagues

• BIT.Group / VietUnion

External Awards/Papers Published in Technical Journals and Conference Proceedings

• External Awards/Papers Published in Technical Journals and Conference Proceedings