Abstract

The demand for increased transmission capacity can be met by dense wavelength-division-multiplexed (DWDM) lightwave systems using two different approaches.¹ The first approach is to increase spectral efficiency (at 10 or 40 Gb/s) within existing C (1530–1570 nm) and L (1570–1610 nm) transmission bands. The second is to make use of the entire low-loss window in silica fiber by increasing the total optical bandwidth. Expansion into bands on the short-wavelength-side of the C-band is considered the most likely option, as it is not affected by spurious fiber-bend losses. These bands are the S-band (1490–1530 nm) and S+-band (1450–1490 nm). For constant channel frequency spacing with 5-nm guard bands, adding the S-band to fully-loaded C- and L-bands increases the capacity by 56%, while adding both S+ and S provides a 119% capacity increase. However, erbium-doped fiber amplifiers, cannot provide gain in the S and S+ bands. Therefore a different amplification approach is needed.

© 2002 Optical Society of America