Lutz Raddatz

In-service measurements of polarization-mode dispersion and correlation to bit-error rate

We introduce a nondisruptive in situ polarization-mode dispersion measurement technique using the sidebands of working channels and show that it compares favorably with the standard Mueller matrix method. Using this technique, we observed time correlations between the instantaneous differential group delay and bit-error rate on a 1000-km field-installed 43-Gb/s transmission system.

Single- and alternating-polarization 170-gb/s transmission up to 4000 km using dispersion-managed fiber and all-Raman amplification

We demonstrate transmission of 170-Gb/s single- and alternating-polarization return-to-zero differential phase-shift keying signals in a recirculating loop using dispersion-managed fiber spans and all-Raman amplification. In the single polarization case, bit-error-ratio (BER) values of 5times10-9 and 1.6times10 -4 were obtained after 960 and 2880 km, respectively. In the alternating polarization case, significantly larger transmission distances were achieved, with BER values of 2times10-9 after 1920 km and 5times10-5 after 4320 km, respectively

1.4 Tb Real-Time Alien Superchannel Transport Demonstration Over 410 km Installed Fiber Link Using Software Reconfigurable DP-16 QAM/QPSK

We report the first successful field trial of a real-time alien superchannel over a 410-km DCM-less optical fiber link using only EDFA amplification. We have demonstrated a record 1.4-Tb/s alien superchannel transported alongside native 40G and 100G wavelengths over a third party optical infrastructure using software reconfigurable DP-16 QAM/QPSK production hardware, achieving spectral efficiency of up to 5.7 bit/s/Hz. Stable long term error-free performance was measured in a real network environment for subchannel spacing as narrow as 36 GHz, giving a spectral efficiency improvement of ~40% compared with standard 50 GHz grid. We have also demonstrated, for the first time, software reconfigurable modulation and capacity of an optical superchannel with subminute switching time. The subchannels can be flexibly and independently reconfigured to enable variable capacity in future flexible optical networks. In addition, robust PMD tolerance of the DP-16 QAM superchannel is measured, which allows network operators to make use of their old, high PMD fibers without the requirement of fiber measurement and selection.

170 Gbit/s single-polarization transmission over 650 km SSMF with 130 km spans using RZ-DPSK

We report on single-polarization 170 Gbit/s transmission over 650 km SSMF using the RZ-DPSK modulation format with base rate 42.6 Gbit/s, with hybrid EDFA/Raman amplification in all five 130 km spans and with error-free transmission without FEC in all tributaries.

160 Gb/s RZ-DPSK OTDM-Transmission over 480 km using 160 km Repeater Spans and Advanced Forward-Error-Correction

The advantages of using RZ-DPSK in combination with advanced forward error correction are shown in an OTDM-transmission experiment of a single-polarization 160 Gbit/s signal over 3 times 160 km dispersion managed fiber.

Technique for in-situ measurements of polarization mode dispersion

A nondisruptive PMD measurement technique (utilizing the sidebands of working channels) is demonstrated, compared to the Mueller matrix method, and applied to a 43Gb/s field-installed system. Correlation between differential group delay and bit-error rate is observed.

Transmission Systems beyond 100 Gbit/s: Status and Technologies

We report on single-channel transmission systems with data rates beyond 100 Gbit/s. The current status and the applied technologies are reviewed, in particular 160-Gbit/s-based systems with long transmission distances and high bit-rates using advanced modulation formats.

Real-time 200 Gb/s 8-QAM transmission over a 1800-km long SSMF-based system using add/drop 50 GHz-wide filters

We demonstrate error-free transmission over 1800 km with 1 dB Q2-margins using a commercially available real-time 200 Gb/s PDM-8QAM transponder (44.8 GBaud) in a super-channel with carriers spaced by 50 GHz using legacy 50GHz-mux-demux stages.

400 Gb/s Real-Time Trials on Commercial Systems for Next Generation Networks

We report the results of a field trial carrying 400-Gb/s real-time dual-carrier PDM-16QAM signals over a 550-km-long commercial system. After the examination of the propagation nonlinear noise statistics nature, we analyze the accuracy of a performance prediction model based on Gaussian nonlinear distortions on the lab replica of on-the-field conditions. Further on, we demonstrate the compatibility of 400-Gb/s real-time dual-carrier PDM-16QAM signals with legacy systems based on a 50-GHz channel grid, yielding 4 b/s/Hz of spectral efficiency over 550-km transmission. In the last part of the paper, we review recently published field trials employing real time 400 Gb/s dual-carrier PDM-16 QAM channels and discuss the potential of such transponders to further increase spectral efficiency beyond 4 b/s/Hz forming superchannels and to be configured by software according to traffic demand.

400Gb/s trials on commercial systems using real-time bit-rate-adaptive transponders for next generation networks

We review recent field trials employing real time 400Gb/s dual-carrier PDM-16 QAM channels. The results demonstrate their compliance not only with nowadays 50-GHz grid network but also with next generation flexgrid networks carrying super-channels.