Yujun Qian

Module for simultaneous C+L-band dispersion compensation and Raman amplification

A single DCF module capable of compensating the dispersion in the full C+L-band of a prototype Raman optimized NZDF has been demonstrated. The residual dispersion from 1530 to 1610 nm was controlled within /spl plusmn/0.07 ps/(nm/spl middot/km). The dispersion margin for 40 Gbit/s transmission is around /spl plusmn/60 ps/nm/sup 3/. Therefore, It will be possible to transmit DWDM 40 Gbit channels in the full C+L-band for around 850 km without any per channel dispersion trimming. The module is also an ideal lumped Raman amplifier. Using a total pump power of 1042 mW an average net gain of 10.1 dB was demonstrated from 1530 to 1607 nm. Noise figure was less than 6 dB in whole wavelength range, and OSNR from double Rayleigh scattering was better than 40 dB. The module will be ideal for use together with the Raman optimized transmission fiber in all Raman systems. Such a system will compared to a conventional system with EDFAs not require any band splitting and therefore support more channel with less loss and lower cost.

Dispersion compensating fibers for non-zero dispersion fibers

We have for the first time to our knowledge demonstrated a single mode dispersion compensating fiber with low PMD, low loss and high Raman gain. The fiber can compensate the dispersion as well as the dispersion slope of the high slope NZDF with RDS of 0.018 nm/sup -1/. The importance of matching not only the dispersion and dispersion slope but also the dispersion curvature has been demonstrated with a new dispersion compensating fiber for low slope NZDF with RDS of 0.018 nm/sup -1/. The residual dispersion is measured to /spl plusmn/0.02 ps/(nm km) in a wide band from 1520 to 1580 nm facilitating 40 Gbit/s transmission for more than 3000 km with no individual channel dispersion correction.

3.2Tb/s (80 /spl times/ 42.7Gb/s) transmission over 20 /spl times/ 100km of non-zero dispersion fiber with simultaneous C + L-band dispersion compensation

Error-free transmission of eighty 40-Gb/s, 100-GHz spaced channels over 2000 km of TrueWave/spl reg/ REACH fiber is achieved. We employ 100-km all-Raman-amplified spans, dispersion-slope-matched dispersion compensating fiber modules covering a 75-nm band, carrier-suppressed return-to-zero modulation format, and forward error correction.

Optimized dispersion compensating Raman amplifier with respect to linear and nonlinear impairments

We demonstrate a 2-stage DCRA providing MPI and SNR ratio improvements of 11.3 dB and 8.8 dB, respectively, compared to 1-stage DCRA at 10 dB gain. 3 dB SNR improvement can be achieved relative to EDFA based passive system.

Dispersion neutral discrete Raman amplifier

We have developed a Raman gain efficient fiber with positive dispersion. In combination with a negative dispersion fiber we have built Raman amplifiers with zero total dispersion and present results on gain, noise figure and MPI.

Gain limitation due to pump stimulated Brillouin scattering in various fibers

We investigate Raman amplification limited by pump stimulated Brillouin scattering for various fibers and low noise pump lasers. The obtainable Raman on-off gain depends on the fiber type and the largest difference is 60% in dB scale.