Tuesday, March 27, 2007

Alcatel-Lucent Outlines Advancements in Optical Transmission

In a series of papers presented at this week's OFC/NFOEC conference in Anaheim, California, Alcatel-Lucent outlined a series of advancements in optical networking, including:

  • The potential for upgrading existing 40 Gbps transparent long-haul transport networks to 100 Gbps Ethernet. Researchers at Bell Labs transmitted ten closely spaced 100 Gbps WDM data channels over a 1,200 kilometer optical transmission distance in a systems experiment that included six optical add/drop nodes like those used in today's transparent mesh networks. Using this design, the researchers achieved an unprecedented spectral efficiency of 1 bit per second per Hertz (b/s/Hz) over the 1200 Km distance using only a single polarization of light.

  • The use of coherent detection instead of conventional direct detection for unmatched resistance to fiber impairments at 40 Gbps. The use of coherent detection instead of conventional direct detection makes the introduction of promising techniques easier, such as using polarisation division multiplexing on top of wavelength division multiplexing, making possible to generate data at 40 Gbps with just 10Gsymbol/s rate. Based on this approach, an ultra long-transmission over 4080 km has been demonstrated for the first time.


  • The ability to receive and convert serial 107 Gbps optical data into lower rate data streams. The company is developing an optical receiver integrates a 100-Gbps photodetector with a 1:2 electronic demultiplexer in a single high-speed package. At such high speeds, packaging these two components in an integrated fashion allows for superior performance compared to having separate photodetector and demultiplexer modules. This is a significant step towards the commercial realization of 100 Gbps serial transmission systems.


  • The first WDM transmission of channels based on serial binary modulation format exploiting full Electronics Time Domain Division Multiplexing (ETDM). Company researchers have demonstrated the WDM transmission of 10 channels, each carrying 107 Gbps bit rate information over 480km. After a recent single-channel demonstration, this is the first WDM transmission of channels based on serial binary modulation format exploiting full Electronics Time Domain Division Multiplexing (ETDM), both at the transmitter and receiver sides.
http://www.alcatel-lucent.com