Abstract

With increasing demand on Internet use and data transmission capacity, the line rates in terrestrial systems are expected to reach 40 Gb/s while maintaining typical terrestrial span lengths of 80 to 100 km.^1–4 In addition to accumulation of amplifier noise and fiber nonlinear effects, dispersion tolerance is another major challenge for 40 Gb/s wavelength division multiplexing (WDM) systems. For instance, a 30 ps/nm dispersion variation results in a 1-dB penalty for 40-Gb/s non-return-to-zero (NRZ) signals in optically amplified systems.² Tight dispersion tolerance requirements, combined with the residual dispersion slope present at the end of the system, make per-band or per-channel dispersion compensation imperative, ⁴ significantly increasing the system complexity and cost. Therefore, it is desirable to achieve low residual dispersion slope in a 40 Gb/s link without introducing system impairments.

© 2002 Optical Society of America