Wilfried Idler

10.2 Tbit/s (256x42.7 Gbit/s PDM/WDM) transmission over 100 km TeraLight/sup TM/ fiber with 1.28 bit/s/Hz spectral efficiency

We demonstrate the transmission of 256 polarization-division and wavelength-division multiplexed channels at 42.7 Gbit/s rate over 100 km of TeraLight/sup TM/ fiber. An overall capacity of 10 Tbit/s is achieved in C and L bands at a record 1.28 bit/s/Hz spectral efficiency.

WDM transmission at 6-Tbit/s capacity over transatlantic distance, using 42.7-Gb/s differential phase-shift keying without pulse carver

We report the transmission of a record 6 Tbit/s capacity over 6120 km distance, involving channels modulated at 42.7-Gb/s bit-rate with differential phase-shift keying (DPSK). The performance is found similar to DPSK with subsequent pulse carving, namely RZ-DPSK.

Rate Adaptation and Reach Increase by Probabilistically Shaped 64-QAM: An Experimental Demonstration

A transmission system with adjustable data rate for single-carrier coherent optical transmission is proposed, which enables high-speed transmission close to the Shannon limit. The proposed system is based on probabilistically shaped 64-QAM modulation formats. Adjustable shaping is combined with a fixed-QAM modulation and a fixed forward-error correction code to realize a system with adjustable net data rate that can operate over a large reach range. At the transmitter, an adjustable distribution matcher performs the shaping. At the receiver, an inverse distribution matcher is used. Probabilistic shaping is implemented into a coherent optical transmission system for 64-QAM at 32 Gbaud to realize adjustable operation modes for net data rates ranging from 200 to 300 Gb/s. It is experimentally demonstrated that the optical transmission of probabilistically shaped 64-QAM signals outperforms the transmission reach of regular 16-QAM and regular 64-QAM signals by more than 40% in the transmission reach.

Influence of fiber nonlinearity on the phase noise to intensity noise conversion in fiber transmission: theoretical and experimental analysis

Intensity noise resulting from the phase modulation to intensity modulation conversion of laser phase noise can be a major impairment in direct detection systems. In this paper, we investigate theoretically and experimentally the influence of fiber nonlinearity on the conversion of laser and optical amplifier phase noise to intensity noise by fiber transmission. Very good agreement of relative intensity noise (RIN) spectra at the output of a standard singlemode fiber between experimental data and theoretical predictions has been achieved. Results reveal that the fiber nonlinearity can enhance significantly the RIN magnitude and lead to a shift of the RIN dips toward higher frequencies, and consequently to a broader RIN spectrum at fiber output.

Transmission of 256 wavelength-division and polarization-division-multiplexed channels at 42.7Gb/s (10.2Tb/s capacity) over 3/spl times/100km of TeraLight/spl trade/ fiber

10.2Tb/s capacity is demonstrated over 3/spl times/100km in C and L bands, using 42.7Gb/s channels. The wavelength allocation was chosen while taking into account narrow optical filtering at the transmitter and receiver ends and second-order Raman pumping is used to improve the signal-to-noise ratio.

Estimation of Soft FEC Performance in Optical Transmission Experiments

We investigate the feasibility of using hard-decision bit error rates or, alternatively, mutual information, both measured before a soft input forward error correction decoder, as a means to estimate performance after soft-decision decoding. Both methods are compared based on a large set of measurement data. We conclude that mutual information seems to be the more reliable measure to estimate soft-decision FEC performance.

Cost-optimized 6.3 Tbit/s-capacity terrestrial link over 17 /spl times/ 100 km using phase-shaped binary transmission in a conventional all-EDFA SMF-based system

We demonstrate the feasibility of 6.3 Tbit/s capacity over 17 /spl times/ 100 km using well-proven all-erbium-doped fiber amplifier technology over a typical ultra-long haul link based on standard fiber. This experiment emphasizes the advantages of our modulation format, namely phase-shaped binary transmission.

Experimental demonstration of nonlinear frequency division multiplexed transmission

We experimentally demonstrate an NFDM optical system with modulation over nonlinear discrete spectrum. Particularly, each symbol carries 4-bits from multiplexing two eigenvalues modulated by QPSK constellation. We show a low error performance using NFT detection with 4Gbps rate over 640km.

Influence of fiber nonlinearity on the fiber transfer function: theoretical and experimental analysis

The influence of fiber nonlinearity on the fiber transfer function is investigated theoretically and experimentally. A rigorous expression for the fiber transfer function using a directly modulated semiconductor laser as an optical transmitter is presented. Very good agreement of fiber transfer function between experimental data and theoretical predictions is achieved. Furthermore, the fiber parameter values extracted from fitting are the same as those obtained from relative intensity noise measurements, and the fiber nonlinearity coefficient value is compared with other published results. A thorough physical explanation for the effect of fiber nonlinearity on the fiber transfer function at low-medium frequencies is provided. Results reveal that in the anomalous dispersion regime the fiber nonlinearity enhances the high-pass behavior typical of the fiber transfer function using a directly modulated laser operating at high bias current, shifts the transfer function dips toward higher frequency, and consequently leads to a larger bandwidth. Furthermore, it is shown that the fiber nonlinearity can provide partial or total compensation of the nonuniform frequency response at low-medium frequencies resulting from a directly modulated laser operated at low bias current.

Transmission of 3×253-Gb/s OFDM-superchannels over 764 km field deployed single mode fibers

We demonstrate transmission of 3×253-Gb/s optical OFDM-superchannels in 100-GHz spacing co-propagating with 112-Gb/s NRZ-QPSK DWDM signals over 764 km field deployed fibers and compare system performance with and without inline DCF modules at the repeater amplifiers.