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Corporate InformationResearch & Development

November 17, 2015

Report from Presenter

Fig. 1 Optical delay detection

Fig. 2 Transceiver prototype

Fig. 3 Experimental results

The 41-st European Conference on Optical Communication (ECOC2015) was held from Sep. 27 2015 to Oct. 1 at Valencia in Spain. The ECOC is one of the renowned conferences in optical communication area with about 1100 world-wide participants from various European countries, USA, Japan, China and so on, and numbers of research outcomes are presented.

Four research papers are presented from the members of the Research and Development Group in Hitachi Ltd., and we presented a paper about next-generation high-speed optical transmission technology for inter data-center and metropolitan use entitled "FPGA prototyping of Single-Polarization 112-Gbit/s Optical Transceiver for Optical Multilevel Signaling with Delay Detection."

Today, emerging large-scale data centers provide various Internet services, and the need for high-speed short-distance inter-data center optical communication is increasing very rapidly. High-speed data transmission technologies for this area are developed very eagerly; for example, the standardization of 400-G Ethernet is in progress which can carry four-times data traffic of current 100-G Ethernet. At the same time, big-scale routers or switches should deploy numbers of optical transceivers for such high-speed optical communication, and their size, power and environmental effects become a serious concern. Therefore, the realization of high-speed optical transceivers with small size and low power consumption is urgently needed.

In this research, we proposed the use of 16-level optical signaling scheme with optical delay detection in order to reduce the size and power consumption of the next-generation high-speed optical transceivers (Fig. 1). The proposed scheme reduces the number of optical transceivers by the use of 16-level multilevel signaling and simplify its configuration by the delay detection, which effectively reduce its size and power consumption. For the feasibility study of the proposed method, we developed a real-time 100-Gbit/s optical 16-level transceiver prototype using FPGAs (Fig. 2). We also successfully demonstrated a 400-Gbit/s data transmission field trial with a four-wavelength configuration of the developed 100-Gbit/s transceivers over an inter-building pre-installed 18.2-km optical fiber at Sapporo city in Hokkaido, Japan (Fig. 3).

With these results, we have shown the feasibility of high-speed and low-power optical multilevel transceivers for future high-capacity short-distance inter-data center optical communication.


This work was partly supported by "The research and development project for the ultra-high speed and green photonic networks" of the Ministry of Internal Affairs and Communications, Japan.


FPGA: Field Programmable Gate Array

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