Wavelength-division-multiplexed system transmits 1 terabit/s over 400 km
Researchers at Lucent Technologies (Holmdel, NJ) have reported transmission of 100 wavelength-division-multiplexed channels of 10 Gbit/s each over a distance of 400 km. The experiment was performed with gain-flattened, silica-based, ultrawide-bandwidth amplifiers (UBWAs), which the researchers reported on last year. The 3-dB UWBA optical bandwidth in the recent demonstration was 84.3 nm and consisted of two bands--a 40.8-nm C-band and a 43.5-nm L-band, according to Yan Sun and Atul Srivastava, who presented the data in February at OFC (San Jose, CA). The gain spectrum of the amplifiers was flattened using long-period fiber-grating filters.
The experimental setu¥combined the output of 24 distributed-feedback lasers and 76 external cavity lasers using four 100-GH¥waveguide grating routers. One of the grating routers was used to multiplex the 30 odd-numbered channels in the C-band, and a second router multiplexed the 30 even-numbered channels. The two sets of C-band channels were then interleaved with 50-GH¥spacing. The 40 channels in the L-band were multiplexed using the third and fourth routers and were transmitted at 100-GH¥spacing. A 4 ¥ 1 coupler combined the output of all four routers. Channel wavelengths ranged from 1536.6 to 1601.4 nm. At the end of the system, channel powers varied by 6.8 dB, or 7.4% of the total gain of 92 dB. All channel error rates were less than 10-9.