Adaptive chromatic dispersion compensation in 1.6 Tbit/s DPSK and ASK transmission experiments over 44...94 km of SSMF

Chromatic dispersion (CD) in single-mode optical fiber distorts pulses and is a big obstacle against the upgrading of long-haul, dynamically routed wavelength division multiplexed (WDM) transmission systems at 10 Gbit/s and beyond. High-performance adaptive dispersion compensators are required as well as reliable low-cost hardware for the detection of residual CD. Targeting high-capacity metro systems, full-band 1.6-Tb/s (40x40Gbit/s) adaptive CD compensation is demonstrated in this experiment, using CSRZ-ASK and NRZ-DPSK modulation formats. A multichannel dispersion compensator, tunable in the range -700 to -1500 ps/nm, is automatically controlled by arrival time detection in one of the 40 transmitted WDM channels. Dispersion and its slope are tuned simultaneously by a thermal gradient of the grating-based compensator to match the parameters of standard single-mode fiber (SSMF) with lengths between 44 and 94 km.