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3 April 2009


Hitachi and Opnext unveil receiver for 100GbE and demo 10km transmission over SMF

At last week’s Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference (OFC/NFOEC 2009) in San Diego, optical module and component maker Opnext Inc of Eatontown, NJ, USA and former parent company Hitachi Ltd of Japan announced the development of a highly sensitive high-speed 25Gb/s receiver for the 100 Gigabit Ethernet (100GbE) standard. Focusing on practicality and cost-effectiveness, the module uses a coaxial package and achieves both high speed and high responsitivity by using a back-illuminated photodiode (PD) with a highly reflective reflector.

Hitachi and Opnext demonstrated 100Gb/s 10km SMF (single-mode fiber) transmission using the newly developed receiver in combination with a 1.3 micron-range 4-channel 25Gb/s EA-DFB (electro-absorption modulator integrated distribution feedback) laser developed based on Hitachi's and Opnext's technology as the light source. This transmission achieves the sensitivity requirements of the IEEE P802.3ba 100GBASE-LR4 standard.

A study by the IEEE 802.3 High Speed Study Group (HSSG) showed that, by the year 2010, the bandwidth required in core networking will be best satisfied by 100Gb/s interfaces. In preparation, the IEEE 802.3ba 40Gb/s and 100Gb/s Ethernet taskforce is currently discussing specifications for 100GbE, for which 1.3 micron-range 4-channel 25Gb/s WDM (wavelength division multiplexing) 10km SMF transmission has been decided by the task force as the most attractive technology. This represents a ten-fold increase in speed from the current 10Gb/s Ethernet standard. The receiver that has been developed is therefore expected 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 micron-range 25Gb/s WDM optical transceiver was the announcement of a 25Gb/s EA-DFB (electro-absorption modulator with integrated distributed feedback laser) suitable for 100 Gigabit Ethernet, and verification of 12km optical transmission, which Hitachi and Opnext introduced at OFC/NFOEC 2008,” Dr Masahiro Aoki, manager of the Nanoelectronics Research Department at Hitachi’s Central Research Laboratory. “This year, Hitachi and Opnext announced the development of a cost-effective 25Gb/s optical receiver for 100GbE, overcoming several technical issues,” he adds.

Consequently, at OFC/NFOEC 2009, Opnext also unveiled what it claims is the first 100GbE optical transceiver for 10km transmission over standard single-mode fiber (SMF). Verification tests using the experimental transceiver, based on the newly developed receiver in combination with the EA-DFB laser developed previously, not only satisfied signal levels required for 100 Gigabit Ethernet but also confirmed 25Gb/s 10km SMF transmission.

The transceiver is compliant with the IEEE P802.3ba 100GBASE-LR4 standard and with the CFP multi-source agreement (MSA) - also announced at OFC, by Opnext together with Finisar and Sumitomo Electric Industries - which is the first industry standard to support next-generation high-speed interfaces including 100 Gigabit Ethernet (100GbE) transmission.

Opnext’s 100GbE transceiver uses its in-house 1310nm 25Gb/s EA-DFB TOSA (transmission optical sub-assembly) and in-house PIN photodiode ROSA ( receive optical sub- assembly) . Both the TOSA and ROSA were developed in collaboration with Hitachi's Central Research Laboratories.

The transceiver’s low power consumption was achieved by using a high-temperature-operation EA-DFB laser based on Opnext and Hitachi’s technologies of using semiconductor material with a temperature-tolerant bandgap structure. In addition, the transceiver’s cost-effective structure and compact size was achieved by using non-coaxial 25Gb/s connections between the TOSA, ROSA and GearBox IC.

“The availability of the 100GbE 10km client-side optical transceiver is key for widespread 100GbE applications,” says Opnext Japan’s president Kei Oki.

The transceiver is hot pluggable and is the same length but double the width of the 10 Gigabit Ethernet industry-standard XENPAK module. It has an SC duplex receptacle optical connecter and a 148-pin electrical connecter with CAUI 10x10Gb/s signals. The transceiver requires a single 3.3V power supply.

Samples will be available in mid 2009, with mass production targeting general availability in mid 2010.

See related item:

Opnext announces Continuously Optimized DPSK for 40Gb/s metro, regional and long/ultra- long-haul transmission

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