March 26, 2009 -- Hitachi Ltd. and Opnext Inc. have developed a highly sensitive high-speed 25-Gbps receiver for the 100-Gigabit Ethernet (100-GbE) standard under discussion for next-generation high-speed optical networks. The receiver module uses a coaxial package and achieves high speed and responsivity by using a back-illuminated photodiode with a highly reflective reflector.
Working together, Hitachi and Opnext report successfully demonstrating a 100-Gbps, 10-km singlemode fiber transmission using the newly developed receiver in combination with a 1.3-m-range, four-channel 25-Gbps electroabsorption modulator-integrated distribution feedback (EA/DFB) laser developed based on Hitachi's and Opnext's advanced technology as the light source. This transmission achieves the sensitivity requirements of the IEEE P802.3ba 100GBase-LR4 standard being discussed. The companies expect the receiver to become a key component in this international standard and support next-generation high-speed interface technology.
"The first step to achieving a 1.3-m-range, 25-Gbps WDM optical transceiver was the announcement of a 25-Gbps EA/DFB laser suitable for 100-Gbps Ethernet, and verification of 12-km optical transmission, which Hitachi and Opnext introduced at OFC/NFOEC 2008. This year, Hitachi and Opnext announced the development of a cost-effective 25-Gbps optical receiver for 100-Gbps Ethernet, overcoming several technical issues," says Masahiro Aoki, PhD, department manager, Nanoelectronics Research Department, Central Research Laboratory, Hitachi Ltd.
A study by the IEEE High Speed Study Group (HSSG) showed that by the year 2010 the bandwidth required in core networking will be best satisfied by 100-Gbps interfaces. In preparation, the IEEE 802.3ba task force is currently discussing specifications for 100-Gbps Ethernet, for which 1.3-m-range, four-channel, 25-Gbps WDM 10-km SMF transmission has been decided by the task force as the most attractive technology. This represents a tenfold increase in speed from the current 10-Gbps Ethernet standard.
Verification tests using an experimental transceiver, based on the newly developed receiver in combination with an EA/DBF laser previously developed, not only satisfied signal levels required for 100-Gbps Ethernet but also confirmed 25-Gbps 10-km SMF transmission.
The technology is being presented during OFC/NFOEC 2009, March 22-26, in San Diego, CA.